:pardon:
http://portland.craigslist.org/mlt/mcy/4359864003.html (http://portland.craigslist.org/mlt/mcy/4359864003.html)
.... and yes, I know, I should go to a 17" wheel ... :flag_of_truce: :flag_of_truce: :flag_of_truce:
but, until then, would these be an improvement?
Thanks!
from the CL ad:
" I have a good set of 1992 Yamaha FJ1200 dual piston Sumitomo calipers. Pads are in good shape. I was going to use these for my bike but it would require too much modification to my bike to make them work. On ebay, a set of 1992 FJ1200 calipers go for $80-$120. I am selling mine for $30. They may fit other bikes. "
Jeff, I have a set of 1990's I will give you !
George
I bought some blue dots for 45.00 a while back.
Why post up when you know what to do?
Quote from: FJ111200 on March 15, 2014, 04:38:56 PM
Why post up when you know what to do?
:dash2: I said I should go to the 17" wheel because that is the prevailing sentiment on this forum. I am happy with the stock wheels and tires but would like to get better braking if it is possible and cost effective. Free or $30 (₤18) seems pretty cost effective. :pardon:
George, Thank you for the offer. I will take you up on it if I get a positive response to my question about fitment and effectiveness. I might even ride over, take you to lunch and pick them up from you.
Jeff
The later model calipers are not a bolt-on swap for the early (anti-dive 16" wheel) models. :negative:
Your $30 would be better spent for a set of bluespots.
Or go ahead and get the ones from George to use when you have the funds for the 17" conversion. :pardon:
Quote from: movenon on March 15, 2014, 02:40:43 PM
Jeff, I have a set of 1990's I will give you !
George
Jeff, if you're doing this on a budget, the late model 4 piston calipers that George is offering are every bit as good as the blue spots, they just don't look quite as cool. Grab them! It is unlikely you will get a better price.
Noel
Quote from: ribbert on March 15, 2014, 07:20:57 PM
the late model 4 piston calipers that George is offering are every bit as good as the blue spots, they just don't look quite as cool.
Noel
Do tell... :boredom:
Quote from: CatTomb on March 15, 2014, 05:59:40 PM
Quote from: FJ111200 on March 15, 2014, 04:38:56 PM
Why post up when you know what to do?
:dash2: I said I should go to the 17" wheel because that is the prevailing sentiment on this forum. I am happy with the stock wheels and tires but would like to get better braking if it is possible and cost effective. Free or $30 (₤18) seems pretty cost effective. :pardon:
George, Thank you for the offer. I will take you up on it if I get a positive response to my question about fitment and effectiveness. I might even ride over, take you to lunch and pick them up from you.
Jeff
Heck if you ride over I will give you a 17 inch FJ front wheel..... The wheel doesn't have rotor's... I don't know if the calipers will fit on your lowers ?
Someone else with more data will have to chime in..
As for the calipers they might fit in one of the "if it fits 5.00 post office box's". Or I could possably drop off the wheel and caliper if I take a divert to Bend en-route to the WCR... I think I can get 2 bikes in the trailer... ? If I don't get busy mine will be a "trailer queen".... :dash2:
George
Quote from: not a lib on March 15, 2014, 08:09:19 PM
Quote from: ribbert on March 15, 2014, 07:20:57 PM
the late model 4 piston calipers that George is offering are every bit as good as the blue spots, they just don't look quite as cool.
Noel
Do tell... :boredom:
Hell, I got some blue anodized paint.............
George
No, the '89-93 calipers will not fit on Jeff's '87 forks.
The mounting holes are different.
Going by memory: the '84-87 are ~3.5"apart and the '89-93 are ~4.0"apart.
That's why we need to convert over to the '89 fork lowers if we want to mount the R-1/6 blue spots.
Unless you go with offset mounting plates on the early fork lowers.
Just because they have more pistons doesn't necessarily make them better. Buy some good brake pads for your stock calipers and you'll improve your brake performance.
Here's a test; which would provide more braking force, a caliper with 2 60mm diameter pistons or a caliper with a single 90mm diameter piston?
Quote from: FJ_Hooligan on March 16, 2014, 01:08:14 AM
Just because they have more pistons doesn't necessarily make them better. Buy some good brake pads for your stock calipers and you'll improve your brake performance.
Here's a test; which would provide more braking force, a caliper with 2 60mm diameter pistons or a caliper with a single 90mm diameter piston?
I don't have a clue but wish I did. The single 90 has more surface area, but I have no idea how the hydraulics are set up or how the effect of the distribution of that force across one large...or two smaller pistons applies to the realized braking force or feel. Would love to learn more on this and understand WHY everyone raves about the R1 blue/gold dots... How are they designed differently to get this better feel...or are they just a better design than the early calipers and just the same as the late model calipers? 1992 FJ1200 minds want to know! :yes:
Cap'n Ron. . .
Wouldn't 2 ,60mm pistons (120mm total) have more surface area than a single 90mm piston?
All I know is that I hated my stock 91 front brakes until I changed them out for the blue dots and FZ1 master cylinder.
Leon
"Going by memory: the '84-87 are ~3.5"apart and the '89-93 are ~4.0"apart."
Mine is bigger............:) :rofl:
I only went with the blue dots because I ran across a set with new pads for about the same price as putting pads on mine... However for the time being I have to use the the stock FJ master cylinder.... I will change that situation this summer.
I will say there is a small bonus, they are a lot lighter. A pound or so off the forks can't be all bad.
George
Ron, I'm assuming you have upgraded to SS brake lines. right? The difference in brake feel is due to (lack) of swelling/expansion of SS vs. rubber OEM lines. Now watch your (89) calipers (off my 89) swell as you squeeze the front brake. It's not much. But they DO flex! I saw them do it-I promise. The gold/blue dot calipers flex A LOT less. That's the difference!
I don't necessarily go along with group-think in general (no slight intended to my FJ brethren). But this is a case of group-think being spot-on.
Go blue dot, don't look back. ( sounds like this needs auto-tune)
Quote from: 1tinindian on March 16, 2014, 02:37:33 AM
Wouldn't 2 ,60mm pistons (120mm total) have more surface area than a single 90mm piston?
All I know is that I hated my stock 91 front brakes until I changed them out for the blue dots and FZ1 master cylinder.
Leon
It's not about hydraulics. If you increase the size of a single piston, you have to increase the size of the pad, and, with a round piston the pad needs to retain it's roughly square shape. The bigger it gets the more the pad contact area moves towards the centre of the disc and becomes proportionately less effective (like having discs that are an inch smaller in diameter)
By having side by side smaller pistons, allowing for a narrower and longer pad, you are using the most efficient part of the disc, the part with the greatest diameter (or maximum torque radius) This really does make a big difference. Think about rear sprocket size and the effect it has on acceleration, same deal, but for deceleration.
To
address offer a humble opinion on Simi Eds point.
I'm not a model expert but I believe the piston size is the same with late model caliper and the blue dots. That just leaves split vs monoblock as the difference. Technically, with enough force applied they will flex. I remain skeptical about observing this with the naked eye though. A sluggish or seized piston will cause the rotor to flex and may give the impression of the caliper spreading.
In the real world, IMO, the amount of force applied, especially with grippy pads, for maximum braking is insufficient to feel any difference between the two. Squeezing hard on the lever for the purpose of a demonstration applies many times more force than the two fingered load required to lock the front wheel and any observed abnormalities are not going to be experienced on the road.
I also think there are far more original calipers not working at 100% efficiency, some way under, than you would imagine. If they don't leak, they never get touched.
I believe the improvement attributed to the blue dots has more to do with the other components.
I would rate the order of improvement by component like this:
Pads (there are some terrible pads out there) The motorbike world seems to largely agree that the EBC HH pads are a standout
SS lines
Adjustable M/C ( I think the adjustable leverage makes a way bigger difference than the bore size)
Calipers
None of this is worth a cracker if your system is not bled properly.
These views are not just theoretical speculation. I have ridden for a considerable time with every configuration of these components letting me evaluate the impact of each one.
Noel
Disclaimer
Before anyone lets the attack dogs out, this is just my opinion.
Quote from: 1tinindian on March 16, 2014, 02:37:33 AM
Wouldn't 2 ,60mm pistons (120mm total) have more surface area than a single 90mm piston?
area of circle = Pi*(Radius)^2, so is 2*Pi*(30mm)^2>Pi*(45mm)^2... turns out not. The single 90mm piston has 12.5% more surface area than the 2 60mm pistons..
I think extending the pressure further along the rotor circumference combined with less flex is why the blue dots would work better objectively (here the linear 120mm is greater than the 90mm, so you press a longer pad more uniformly), but matching the right MC for the smaller piston area would be important to get the right "feel". Just slapping on the smaller piston area without changing the MC would give more travel for the force applied making the brakes feel worse most likely.
Frank
I have Blue dots, SST lines, HH pads and stock MC and my impression is less force is required with better feel. I don't notice any issue with lever travel. Perhaps it is not enough for me to notice. That is my $0.02
Don't forget unsprung weight.
Smaller multiple pistons allow the use of narrower pads, and thus narrower rotors, lighter in weight.
Noel...that makes a lot of sense to me with the better distribution of multiple smaller pads and where on a rotor they are applying force.
I'm already running the '92 calipers with stainless lines. They are serviced well and properly bled. Short of dropping a slight about of weight, I'm not compelled to change out the calipers and go through the ABS bleeding again!
Cap'n Ron. . .
Lots of good info coming through, but, has anyone addressed Jeff's original question? Was there an improvement from early to late model calipers? What year?
Cap'n Ron. . .
Quote from: Capn Ron on March 16, 2014, 12:47:00 PM
Lots of good info coming through, but, has anyone addressed Jeff's original question? Was there an improvement from early to late model calipers? What year?
Cap'n Ron. . .
Need to fine someone with stock 84-87 and a stock 88-93 to get an answer.
Jeff if I were you I would keep my eye out for a set of 88-93 front forks or at least 2 lowers from a bent set. Once you have those you have some options. Up grade to 88-93 brakes, 87-88 FZR wheel, blue dots etc..
You are welcome to the parts I have if and when you need them.
George
Quote from: Capn Ron on March 16, 2014, 12:47:00 PM
Lots of good info coming through, but, has anyone addressed Jeff's original question? Was there an improvement from early to late model calipers? What year?
Cap'n Ron. . .
I have both early and late model FJs and after riding both in stock form, comparing oem to oem (m/c, calipers and Yamaha pads) the late model brakes 'feel' better.
In the USA, FJ brake upgrade was made in '89 when they went to the 17" front rim and the lighter single faced rotors.
In fact the whole front end assembly on the late model FJ's is superior with a lighter wider rim and rotors.
The early 16" FJ rims are narrow and pig heavy.
Quote from: FJmonkey on March 16, 2014, 10:23:10 AM
I don't notice any issue with lever travel. Perhaps it is not enough for me to notice. That is my $0.02
The adjustability of the M/C is not about travel (although it does change) but it increases the mechanical advantage or leverage, that what improves the feel.
Noel
Quote from: Capn Ron on March 16, 2014, 12:47:00 PM
Lots of good info coming through, but, has anyone addressed Jeff's original question? Was there an improvement from early to late model calipers? What year?
Cap'n Ron. . .
My disclaimer may have been confusing. It applied to the second half of my post, blue dots vs standard calipers.
The first part about single piston vs multi piston (early vs late model) is fact. It is ALL about where the pad operates on the disc. It is not speculation or opinion. It has nothing to do with weight or flex or spreading load.
It allows more of the pad to operate on the most efficient part of the disc for reasons already explained.
Noel
Fjowners is like a box of chocolate hornets, you never know what you're gonna stir up and get in return.
Thanks for all of the feedback. Kelly and I got a great 130 mile ride in today. Beautiful day and great to be back on the bike. I rode four days in the last eight, two on the KTM in the dirt.
Today's loop took us past Smith Rock and the Prineville Reservoir. We stopped for a picnic in a OHV staging area. Loved the looks from the Offroaders as we pulled in.
https://goo.gl/maps/NEPIm
Bike ran great, brakes worked ... good?
I had the pleasure to ride Baldy's FJ one day at Randy's. It is a very different bike. I like the looks of stock and I like the feeling of riding something that is almost 30 years old.
But, it is no longer stock. RPM fork valves, springs, brace, oil filter, unipods, radials ...
:flag_of_truce: I guess 17" wheels and blue dots are gonna have to be next ... or right after the RPM rear shock :mail1:
I could definitely feel the difference in braking with Kelly on the back.
:bye: :bye:
Thanks again for the chocolates. :pardon:
Oh, and in the meantime I ordered some EBC HH pads :blum1:
Quote from: simi_ed on March 16, 2014, 05:48:58 AM
Ron, I'm assuming you have upgraded to SS brake lines. right? The difference in brake feel is due to (lack) of swelling/expansion of SS vs. rubber OEM lines. Now watch your (89) calipers (off my 89) swell as you squeeze the front brake. It's not much. But they DO flex! I saw them do it-I promise. The gold/blue dot calipers flex A LOT less. That's the difference!
I don't necessarily go along with group-think in general (no slight intended to my FJ brethren). But this is a case of group-think being spot-on.
Go blue dot, don't look back. ( sounds like this needs auto-tune)
Ed, I don't need to remind you of how I felt about the stock brakes on my 91, but to you others, I was a hard sell on updating the brakes on the FJ.
I did it, finally, and will never look back.
I now have two complete sets of 91 and 93 front calipers, never to be used again.
Leon
I have owned a 85' with a stock brake system. My 89' came with a stock brake system and a 16" front wheel. My 87' came with 89' forks, 17" front wheel and 89' calipers.
The 85', I bought in 88' so the brake system was still fairly fresh. It was always a complaint of mine that it needed stronger brakes. The bike could very easily over cook a corner with the lack of forceful brakes.
The bikes I currently own,
The 89', I slowly upgraded the brakes and the front wheel. First was the Blue spots with rubber lines and the 16" wheel and vented rotors. The 89' OEM calipers were an improvement over the 84'-87' calipers, but the switch over to the Blue spots made a large difference. Added the 17" wheel with new rotors and noticed a small improvement. Next was the braided lines, another noticeable step in braking force. Finally I added a 98' VFR800 master cylinder and WOW is all I can say for the stopping power of the whole system. The brake system easily overwhelmed the OEM suspension enough to have the fairing contact the fender. Resolved that with new springs and fork valves from Randy.
The 87' came with 89 forks, calipers and FZR wheel. The braking was very marginal when I purchased the bike. I never saw any fluid leaks, but I suspect the calipers needed to be rebuilt. I put a 10' ZX10 master cylinder, braided lines and gold dots on at the same time and cured the braking issues, braking power is almost on par as the 89'. The rotors still need to be addressed as they are near the end of their life.
Fred
Quote from: aviationfred on March 16, 2014, 10:50:04 PM
I put a 10' ZX10 master cylinder.........
Fred
Of course the brakes are going to be good with a 10 foot m/c!!
:dash2: :dash2: :dash2: :dash2: :dash2: :dash2: :dash2: :dash2:
It appears I don't know as much about brakes as I thought I did.
Could someone tell ME then, without anecdotes, why blue dots are better.
Noel
I think Fred brings up a good point, about the necessity of the 14mm m/c in the mix.
On my '84, when I did the late model fork lowers, FZR rim, R-1 blue spots and Spiegler lines, yet I was still using the FJ oem 5/8" m/c, I remember thinking, yea, these brakes are better....but still not that great.
It was only after I added the FZ1 14mm m/c did I really notice the improvement in being able to better modulate the front brakes. 2 finger braking at its best.
I've concluded that the front brake system is just that...a system. The synergy of parts working together.
Leave out one part, and your results will be less than optimal.
That said, I've always wondered if a modern radial m/c would improve things even better...? Comments?
I just can not get my head around at looking at a urine cup on my handle bars
Quote from: ribbert on March 16, 2014, 11:35:10 PM
:dash2: :dash2: :dash2: :dash2: :dash2: :dash2: :dash2: :dash2:
It appears I don't know as much about brakes as I thought I did.
Could someone tell ME then, without anecdotes, why blue dots are better.
Noel
Here's my take:
The 1 piece body is stiffer, stronger than a bolt together 2 piece caliper, and given the same amount of pressure from the m/c, thus able to transmit more hydraulic force to the pistons, thus the pads, thus the rotor.
Leon, I was thinking of our emails back & forth about updating to blue dots. You were a hard sell!!! Like me, you didn't want to drink the Kool-aid, yet you too are a convert to the Church of the Blue-Dot. Hallelujah :drinks:
Noel, I think that Frank's (Flynt) explanation of the reduce piston area with more linear area, more braking potential due to the use the outer rotor surfaces and my description of the visible flexing of the late model 4 piston calipers sum up what's happening and the improvements. If you don't believe, that's OK, you're entitled to your opinion.
Maybe refresh your memory of the "sales pitch" we had to do on Leon http://www.fjowners.com/index.php?topic=2057.0 (http://www.fjowners.com/index.php?topic=2057.0) to finally convince him to upgrade. I don't think he's going back to OEM calipers; in fact I've NEVER heard of anyone that has done the upgrade and them gone back to OEM.
Ed, you've combined the two things being discussed into the one post. Single vs multi piston and blue dot vs standard (late model) calipers.
The explanation about maximum effect being at the outer part of the disc and this being the sole reason for multi piston calipers and hence rectangular pads was mine not Franks.
A point that seems to have been widely missed is this is not my opinion, it is a fact.
Quote from: simi_ed on March 17, 2014, 01:50:14 AM
........If you don't believe, that's OK, you're entitled to your opinion..........
.........Maybe refresh your memory..........
FFS, words fail me!
(http://farm4.staticflickr.com/3730/13213336085_b5c80545bf_o.jpg)
This discussion is futile, forget I spoke, we are obviously on a different page here.
Noel
Quote from: Pat Conlon on March 17, 2014, 01:25:09 AM
I just can not get my head around at looking at a urine cup on my handle bars
Pat, these black anodised covers tend to "disappear" into all the other handlebar hardware. I have seen them in the flesh, not too bad if you're stuck with a urine cup. Way smarter looking than socks.
(http://m2.uxcell.com/photo_new/20130906/g/ux_a13090600ux0355_ux_g03.jpg)
Noel
Pat, Leon, Fred, Ed and Noel - Thank you! :good2:
After reading replies and rereading past posts, I'm thinking I should replace the brake fluid and, as Pat has been suggesting since I first considered the bike, SS lines. (insert brick-thick skull cartoon here)
I can't play the banjo, would this package work? I found the link in a previous post (thanks to Fred)
http://www.ebay.com/itm/86-87-YAMAHA-FJ-1200-Non-ABS-Front-Brake-Line-Kit-Braided-S-S-Brake-Lines-/400378230354?pt=Motorcycles_Parts_Accessories&hash=item5d3866f652&vxp=mtr (http://www.ebay.com/itm/86-87-YAMAHA-FJ-1200-Non-ABS-Front-Brake-Line-Kit-Braided-S-S-Brake-Lines-/400378230354?pt=Motorcycles_Parts_Accessories&hash=item5d3866f652&vxp=mtr)
I searched without success for a post of brake bleeding tips ... any FJ specific tips would be greatly appreciated.
Never Mind
:drinks:
Quote from: simi_ed on March 17, 2014, 01:50:14 AM
Leon, I was thinking of our emails back & forth about updating to blue dots. You were a hard sell!!! Like me, you didn't want to drink the Kool-aid, yet you too are a convert to the Church of the Blue-Dot. Hallelujah
Noel, I think that Frank's (Flynt) explanation of the reduce piston area with more linear area, more braking potential due to the use the outer rotor surfaces and my description of the visible flexing of the late model 4 piston calipers sum up what's happening and the improvements. If you don't believe, that's OK, you're entitled to your opinion.
Maybe refresh your memory of the "sales pitch" we had to do on Leon http://www.fjowners.com/index.php?topic=2057.0 (http://www.fjowners.com/index.php?topic=2057.0) to finally convince him to upgrade. I don't think he's going back to OEM calipers; in fact I've NEVER heard of anyone that has done the upgrade and them gone back to OEM.
Quote from: Pat Conlon on March 17, 2014, 01:25:09 AM
I've always wondered if a modern radial m/c would improve things even better...? Comments?
I have the one that was on Klavdy's bike... replaced it when I did the big overhaul on Wiz. IMHO that m/c felt like squeezing a 2X4 (no feel whatsoever) and the FZ1 MC is a 1 finger operation (with the 320 Brembo rotors and EBC HH in front). Night and day difference.
If you want to try a radial m/c, I'm happy to set you up.
Frank
Quote from: FJ_Hooligan on March 16, 2014, 01:08:14 AM
Just because they have more pistons doesn't necessarily make them better. Buy some good brake pads for your stock calipers and you'll improve your brake performance.
Here's a test; which would provide more braking force, a caliper with 2 60mm diameter pistons or a caliper with a single 90mm diameter piston?
A great mechanic friend of mine gave me some basic info about brakes that I've never forgotten. Brakes convert kinetic energy into heat. "Piston AREA not diameter affects the force." Quotes because they're not my words.
Rick
I think I also read somewhere in this thread that adjustable levers made a big difference in (his/her) braking. Again, I will quote, "for brakes to convert kinetic energy into heat they must be applied with great force...The primary mechanical principle used to increase the application force in every brake system is leverage." So kudos to that person who suggested adjustable levers to increase leverage. AMEN.
Quote from: RD56 on March 17, 2014, 12:39:00 PM
I think I also read somewhere in this thread that adjustable levers made a big difference in (his/her) braking. Again, I will quote, "for brakes to convert kinetic energy into heat they must be applied with great force...The primary mechanical principle used to increase the application force in every brake system is leverage." So kudos to that person who suggested adjustable levers to increase leverage. AMEN.
I don`t usually comment on things mechanical `cause I didn't want to remove all doubt on my expertise, but I can tell ya I first learned about leverage on my school push bike.
When ya turned tha thing upside down and spun a wheel it was far easier ta slow it down by placing the fingers against the spokes further out from the axle compared ta closer to the axle (which did make my fingers hotter!). I eventually developed this new found knowledge further into my combat strategy.
One particular bully use ta ride pass me real close from behind, whenever he had the opportunity on the way home from school. I practised it a bit before I got it right, but if you grabbed his rear tyre with confidence (The most outer distance from tha axle) with my strongest hand (Never did develop the grab inta two hands which woulda been better if he was going real fast!) followed by immediately lifting up (opposite ta Gravity) while swinging my mass directly behind his direction of force, I could easily stop dead the mass of said pushbike.
However my leverage was not enough to have the same affect on the riders body mass.....which continued forward.....this of course left me at a considerable advantage for the following heat!
True story, but Yeah I`m bored cause I got given a brand new 4 wheel drive at work yesterday (with two diff locks and massive tyres!)...and I`m not allowed ta play with it till 8.30am. Can`t wait ta take some pics too! :drinks:
+1 for diff locks!! :yahoo:
Quote from: RD56 on March 17, 2014, 12:27:14 PM
Quote from: FJ_Hooligan on March 16, 2014, 01:08:14 AM
Just because they have more pistons doesn't necessarily make them better. Buy some good brake pads for your stock calipers and you'll improve your brake performance.
Here's a test; which would provide more braking force, a caliper with 2 60mm diameter pistons or a caliper with a single 90mm diameter piston?
A great mechanic friend of mine gave me some basic info about brakes that I've never forgotten. Brakes convert kinetic energy into heat. "Piston AREA not diameter affects the force." Quotes because they're not my words
Rick
So what's (PI/4)*Diameter^2?
Quote from: RD56 on March 17, 2014, 12:39:00 PM
I think I also read somewhere in this thread that adjustable levers made a big difference in (his/her) braking. Again, I will quote, "for brakes to convert kinetic energy into heat they must be applied with great force...The primary mechanical principle used to increase the application force in every brake system is leverage." So kudos to that person who suggested adjustable levers to increase leverage. AMEN.
Adjustable levers don't change anything except the distance they are from the bar. Unless they are longer, the leverage is the same since the pivot point of the lever is fixed. The primary force multiplication in a braking system is hydraulic multiplication. You get that by applying force on a small diameter/area piston which creates a pressure in the fluid (psi). In the caliper, that pressure is applied to the larger area of the pad piston thus creating a force that presses the brake pad against the rotor.
Simple math. On the master cylinder side: Force/area = pressure. Higher force or smaller piston area increases pressure
In the caliper: Pressure * area = force. For a given amount of pressure, a larger piston generates more force.
You want the "great force" to be generated in the caliper, not with lever pull.
FJ piston diameter 5/8" (about 15.8 mm). I think the R1's / R6 etc. are 14mm diameter? When I get to that point I will go with a 14mm piston.
And stay with DOT 4 (popcorn) (popcorn).
George
Quote from: movenon on March 17, 2014, 04:44:09 PM
And stay with DOT 4 (popcorn) (popcorn).
George
Luddite. :biggrin: (popcorn)
Quote from: not a lib on March 17, 2014, 04:53:18 PM
Quote from: movenon on March 17, 2014, 04:44:09 PM
And stay with DOT 4 (popcorn) (popcorn).
George
Luddite. :biggrin: (popcorn)
It's all Jeff's fault, he stirred it up :drinks:
George
P.S. DOT 4 is the best...
I guess it would make sense to put a stop to this right now ... since it's about brakes. :rofl: :rofl: :rofl: :rofl: :rofl:
I would like to apologize to the forum and its members ... er ah ... participants for any undue stress or anxiety my simple question provoked.
I'm 53 years old, I've been married. I have kids, girls. I should know better. :dash1: :wacko3:
No blood no foul. Although it might appear differently this has been a healthy debate. I hope you were able to sift through the noise and get the info you were looking for.
Whatever you do, don't get'me going on the best oil to use :negative:
Quote from: FJscott on March 17, 2014, 10:28:35 PM
No blood no foul. Although it might appear differently this has been a healthy debate. I hope you were able to sift through the noise and get the info you were looking for.
Whatever you do, don't get'me going on the best oil to use :negative:
Aw geezzz now what are we going to do............ (popcorn) :lol:
George
Quote from: CatTomb on March 17, 2014, 09:30:39 PM
I guess it would make sense to put a stop to this right now ... since it's about brakes. :rofl: :rofl: :rofl: :rofl: :rofl:
I would like to apologize to the forum and its members ... er ah ... participants for any undue stress or anxiety my simple question provoked.
I'm 53 years old, I've been married. I have kids, girls. I should know better. :dash1: :wacko3:
For good or bad, I think these type of threads bring out all the views, and an educated decision can come out of it.
No apologies , we're all good here!
You will make your way to the 17" front wheel at some point, and all this will be moot!
Leon
No stress on my side of the pond. I offered my 2¢, apparently it wasn't worth that much. I hope my input was worth something ...
Quote from: simi_ed on March 18, 2014, 02:11:07 AM
..... I offered my 2¢, apparently it wasn't worth that much.
Apologies to Simi Ed. On re reading my post I realise it appears the latter comments were directed at you, they weren't. I was just airing my general frustration with the entire thread. Yours just happened to be the most recent and the one I replied to. I should have proof read it and made that distinction.
Noel
Quote from: CatTomb on March 17, 2014, 09:30:39 PM
I would like to apologize to the forum and its members ... er ah ... participants for any undue stress or anxiety my simple question provoked.
Why? Discussions like this are the life blood of the forum and occasionally some useful information comes from them. :lol:
You may have noticed that the discussions always remain civilised and never resort to abuse and name calling. (mostly)
People here remain respectful of each other, even if they disagree.
Noel
BTW, some adjustable levers also change tha fulcrum point.....Saves ya hav`en ta weld a crow bar extension on the brake "Lever" ta increase (durrh :scratch_one-s_head: ), tha leverage! :bye2:
:drinks:
Can someone tell me why on the blue dot (and late model) calipers the front piston is larger than the rear one?
Noel
Quote from: ribbert on March 18, 2014, 06:40:31 AM
Can someone tell me why on the blue dot (and late model) calipers the front piston is larger than the rear one?
Noel
Heat dissipation and clamping force. Depending how ya look at it tha leading edge heats the disc so the trailing edge has ta be bigger to get the same force before brake fade. (Okay, okay I googled it, but I already knew it was along that line.)
I guess if they were both tha same size the weakest point would be where it gets hottest, but best to have the weakest point even over the two pistons areas for more efficiency. ....yeah I`m off ta bed now. :drinks:
I could offer a theory ... :dash1:
Accepted. :good:
Just for information only.
This is from http://www.fjmods.co.uk/BrakeUpgrades.htm#Anchor96821 (http://www.fjmods.co.uk/BrakeUpgrades.htm#Anchor96821)
"Earlier 84-87 FJ's can benefit from four pot calipers from a FZR400RR. This mod was discovered by Piolo Martin from Chile. To my knowledge no-one's discovered this easy modification before. Piolo reports a terrific improvement upon his original calipers."
I don't know if anyone has done this but it might be worth a look.
George
Quote from: movenon on March 18, 2014, 02:43:47 PM
Just for information only.
This is from http://www.fjmods.co.uk/BrakeUpgrades.htm#Anchor96821 (http://www.fjmods.co.uk/BrakeUpgrades.htm#Anchor96821)
"Earlier 84-87 FJ's can benefit from four pot calipers from a FZR400RR. This mod was discovered by Piolo Martin from Chile. To my knowledge no-one's discovered this easy modification before. Piolo reports a terrific improvement upon his original calipers."
I don't know if anyone has done this but it might be worth a look.
George
This was batted about on the old FJ lists... good luck trying to find a pair of those.
IIRC, the FZR400RR didn't even make it Stateside.
Unobtainable. Rare as hen's teeth.
The FZR400RR was a special edition and never imported to the US, sold only in Europe and perhaps the JDM.
I checked back in the '90's. Plenty of FZR400's out there, but the RR version was not to be found.
Save your time and effort, trust me.
I recently read a web article that stated only about 30 FZR400RR are still registered in the UK. Rare as hen's teeth, spot on Pat...
My question is, why are we chasing phantom parts and pieces and ignoring the obvious and mostly readily available parts to get to the final solution?
89+ lower FJ forks and the stock 17" wheel, or the 3.5" FZR wheel, and the blue dots.
Problem and mystery solved.
I realize time and money have to find there way to the person doing the mods, but this has been such a well covered and proven upgrade, I'm surprised that we are even debating it.
Quote from: Capn Ron on March 16, 2014, 12:47:00 PM
Lots of good info coming through, but, has anyone addressed Jeff's original question? Was there an improvement from early to late model calipers? What year?
Cap'n Ron. . .
Great debate. My experience:
My son's 84 and my '92 blue spots, ss lines, original MC - two finger braking, great feel
My friends '84 ...all stock including anti-dive, original lines, no where near as good a feel as above and requires much more hand force.
Our '86 stock with anti dive eliminated, EBC high ends pads (from Pat C) - needs much more hand force for braking (calipers may not be all that good?)
Last summer the other 92 (now the project) MC started to leak so we replaced it with a 97 YZF 600 MC ("radial"?), SS lines. Brakes just as good as the blue spots above.
I would agree with Noel that the blue spots look better (and may be a bit lighter) but I am not sure they are much better than the original two piston FJ calipers. But hey, looks get the chicks, right?
If the snow ever melts, I will be interested in how the six pot R1 set-up stops the old girl. I have the 97 YZF 600 MC on it.
Jeff
Quote from: jscgdunn on March 18, 2014, 08:20:01 PM
`11
>>Last summer the other 92 (now the project) MC started to leak so we replaced it with a 97 YZF 600 MC ("radial"?), SS lines. <<
>>If the snow ever melts, I will be interested in how the six pot R1 set-up stops the old girl. I have the 97 YZF 600 MC on it.<<
Jeff
The YZF m/c isn't radial, but it
is 14mm.
No OEM R1 six-pot calipers that I'm aware of... YZF750, perhaps? :scratch_one-s_head:
(http://farm8.staticflickr.com/7372/11719653776_2ac4b19daf_c.jpg)
Jeff
Ah, the USD ones.. okay.
Forgot about those ones. :pardon:
Good update and info on the FZR400RR. I was just throwing out some information that was on the net.. I installed the blue dots this winter and will use the stock FJ MC until time and funds allow a MC upgrade. "Avaitionfred" steered me to using a Honda GL1800 MC. The brake line fitting is forward facing so you can use the FJ lines, no urine cup, adjustable lever, and has a 14mm piston. And for what ever it worth they make a replacement fluid cap with built in electrical switch's. Most stuff in the digital camp fire while on the subject.
Leon is correct, just go with what works. The problem is economically locating the 88-93 lowers or building adapter plates for the older FJ lowers. The blue dots are cheap.
George
To continue this:
What exactly is a radial MC? I did a bit of research but all I could come up with is that the urine cup style is a "radial". Probably a poor conclusion. When I looked at the R1 MCs they looked the same as the 1997 YZF 600 one I already had...so I stuck with it. I understand the 2009 R1 calipers are "radial" but I could not track down a good definition of a radial MC.
Thanks,
Jeff
(http://s7d2.scene7.com/is/image/Motosport/BRM-RCS-19_sw1?$NewPDP2$)
A radial master cylinder has the piston oriented in line with direction of the pull of the lever.
conventional (axial) master cylinders have the piston at right angle in direction of the pull of the lever.
Here's a good discussion: http://www.ducati.ms/forums/80-hall-wisdom/27159-conventional-axial-vs-radial-master-cylinders.html (http://www.ducati.ms/forums/80-hall-wisdom/27159-conventional-axial-vs-radial-master-cylinders.html)
Cheers
Quote from: Pat Conlon on March 19, 2014, 11:05:38 AM
(http://s7d2.scene7.com/is/image/Motosport/BRM-RCS-19_sw1?$NewPDP2$)
A radial master cylinder has the piston oriented in line with direction of the pull of the lever.
conventional (axial) master cylinders have the piston at right angle in direction of the pull of the lever.
Here's a good discussion: http://www.ducati.ms/forums/80-hall-wisdom/27159-conventional-axial-vs-radial-master-cylinders.html (http://www.ducati.ms/forums/80-hall-wisdom/27159-conventional-axial-vs-radial-master-cylinders.html)
Cheers
One thing that's hard to argue about is the beauty of the design.
Quote from: RD56 on March 19, 2014, 11:28:13 AM
Quote from: Pat Conlon on March 19, 2014, 11:05:38 AM
(http://s7d2.scene7.com/is/image/Motosport/BRM-RCS-19_sw1?$NewPDP2$)
A radial master cylinder has the piston oriented in line with direction of the pull of the lever.
conventional (axial) master cylinders have the piston at right angle in direction of the pull of the lever.
Here's a good discussion: http://www.ducati.ms/forums/80-hall-wisdom/27159-conventional-axial-vs-radial-master-cylinders.html (http://www.ducati.ms/forums/80-hall-wisdom/27159-conventional-axial-vs-radial-master-cylinders.html)
Cheers
One thing that's hard to argue about is the beauty of the design.
Or the ulgy-osity of the required urine cup/reservoir!!!
Asked and answered!. Thanks!
Quote from: simi_ed on March 19, 2014, 11:54:39 AM
Quote from: RD56 on March 19, 2014, 11:28:13 AM
Quote from: Pat Conlon on March 19, 2014, 11:05:38 AM
(http://s7d2.scene7.com/is/image/Motosport/BRM-RCS-19_sw1?$NewPDP2$)
A radial master cylinder has the piston oriented in line with direction of the pull of the lever.
conventional (axial) master cylinders have the piston at right angle in direction of the pull of the lever.
Here's a good discussion: http://www.ducati.ms/forums/80-hall-wisdom/27159-conventional-axial-vs-radial-master-cylinders.html (http://www.ducati.ms/forums/80-hall-wisdom/27159-conventional-axial-vs-radial-master-cylinders.html)
Cheers
One thing that's hard to argue about is the beauty of the design.
Or the ulgy-osity of the required urine cup/reservoir!!!
Obviously, you've never been stopped on the side of the road with no place to pee.
Quote from: Pat Conlon on March 19, 2014, 11:05:38 AM
(http://s7d2.scene7.com/is/image/Motosport/BRM-RCS-19_sw1?$NewPDP2$)
A radial master cylinder has the piston oriented in line with direction of the pull of the lever.
conventional (axial) master cylinders have the piston at right angle in direction of the pull of the lever.
Here's a good discussion: http://www.ducati.ms/forums/80-hall-wisdom/27159-conventional-axial-vs-radial-master-cylinders.html (http://www.ducati.ms/forums/80-hall-wisdom/27159-conventional-axial-vs-radial-master-cylinders.html)
Cheers
Thank you for posting that link Pat...It's exactly the tech information I was looking for in regards to why all the chatter about a 14mm M/C during the blue dot swap. I'm supposing it's a closer hydraulic match for the original blue dot setup?
As to Noel's point...What is the technical difference between the blue dot calipers and the late model factory calipers? Piston size, piston distribution, flex of the housing, and to some degree, weight?
I'm down with a cold at the moment and have SimiEd's old factory calipers ('89) in the garage. I'll go measure up the pistons (has this been done already?) and if someone with a set of blue or gold dots laying around could do the same, it'd help put this topic in perspective.
Cap'n Ron. . .
Ron, the best explanation on why the 14mm vs oem 16mm (5/8") m/c works better with the R1 blue spots was explained to me as follows:
The 28% smaller area of the 14mm piston means that the stroke has to be accordingly longer to move the same volume of fluid to exert the same pressure on the caliper pistons.
It's this longer stroke that gives better modulation (feel) to the brakes.
Both m/c's have the ability to lock the front wheel so overall force (pressure) is not the issue, it's all about the control, or feel of the lever prior to, or just below, the threshold.
Does that help?
I'm sure something is technically wrong with the above explanation, but fear not, Noel will chime in shortly. (popcorn)
Quote from: Pat Conlon on March 19, 2014, 06:07:35 PM
Ron, the best explanation on why the 14mm vs oem 16mm (5/8") m/c works better with the R1 blue spots was explained to me as follows:
The 28% smaller area of the 14mm piston means that the stroke has to be accordingly longer to move the same volume of fluid to exert the same pressure on the caliper pistons.
It's this longer stroke that gives better modulation (feel) to the brakes.
Both m/c's have the ability to lock the front wheel so overall force (pressure) is not the issue, it's all about the control, or feel of the lever prior to, or just below, the threshold.
Does that help?
I'm sure something is technically wrong with the above explanation, but fear not, Noel will chime in shortly. (popcorn)
Oh, yeah, I get that. On my earliest post in this thread, I mentioned the hydraulic issue mostly because a lot of folks change to the 14mm M/C along with the blue dot change. I wasn't aware of the factory size M/C being 16mm and in which direction (more or less modulation) this would take you. All this good information is trickling in in bits and pieces and I will be adding the factory caliper measurements in my next post.
So...would the modulation (lever feel) change from factory if one were to *just* change the calipers to blue dots? Or is that exactly the problem...that the OEM 16mm M/C pushes too much fluid for the blue dots making the lever too "hard"?
Cap'n Ron. . .
I can't answer that based on my experience.
I never tried the 14mm m/c with either the '84 or '92 oem calipers.
Just funneling in some more data...Not sure if this has been posted somewhere over the years, but I have a spare set of '92 front calipers in the stockpile so I did some measuring:
There are four moving pistons in each front caliper and they are 32mm in diameter each giving 1608mm^2 of piston area:
(http://fjowners.com/gallery/7/697_19_03_14_5_37_05_0.jpeg)
They are placed 10mm apart from each other:
(http://fjowners.com/gallery/7/697_19_03_14_5_37_07_1.jpeg)
Giving a total pad contact (including the 10mm gap) of 74mm long x 32mm high:
(http://fjowners.com/gallery/7/697_19_03_14_5_37_11_2.jpeg)
A single front caliper (minus the bleed screw) comes in at 1124 grams:
(http://fjowners.com/gallery/7/697_19_03_14_5_37_14_3.jpeg)
So far, all I can find on the blue dots shows the weight to be 720 grams?? :shok: Sheesh, that's getting near a pound of unsprung weight savings per caliper! The gold dots with the aluminum pistons are listed at 650 grams each...well over a pound savings each over OEM. Not bad at all!
They also appear to use different size pistons within the same caliper. 27mm and 30mm...both smaller than our OEM pistons and having 1279mm^2 of total piston area. This would certainly explain why folks would want to change to a 14mm master cylinder...the OEM 16mm M/C would give too hard a lever feel with just a caliper change.
There is talk of some heat advantage of having the trailing piston be larger than the leading piston...short of that, the blue dots have just over 20% *less* piston area contacting each brake pad than the factory caliper. Given that, WHY are they providing better braking? Is it the different sized pistons approach? Eh...maybe. Lighter weight? Nice, but no braking advantage there. Less flex? I'd buy that as it would allow more clamping force, but are they actually stiffer? ...and does that over-compensate for the smaller piston contact area? Is it just that we're changing 20+ year old setups that haven't been serviced in years with a complete brake system makeover (SS lines, fresh master cylinder, serviced calipers, fresh fluid, high-end pads (EBC HH) and a proper bleeding)?? :scratch_one-s_head:
Still looking for the smoking gun and obviously have too much time on my hands. :biggrin:
Oh...and don't anyone tell my girlfriend that I used her food scale to weigh greasy motorcycle parts...Thank you! :hi:
Cap'n Ron. . .
"So far, all I can find on the blue dots shows the weight to be 720 grams?? shok Sheesh, that's getting near a pound of unsprung weight savings per caliper! The gold dots with the aluminum pistons are listed at 650 grams each...well over a pound savings each over OEM. Not bad at all!"
On the weight issue, I also found that the Race Tech springs also take some weight out of the system. My FJ calipers weighed in at 1.065 kg each with pads. Not a big thing but it all adds up. I imagine aftermarket rotors are also lighter.
Talk to Mark, I think he is, or was running a stock 5/8 MC with the blue dots.
Good information Ron. Keep up the flow :good2:
George
Quote from: movenon on March 19, 2014, 08:49:45 PM
Talk to Mark, I think he is, or was running a stock 5/8 MC with the blue dots.
George, if you mean me as the Mark you refer to then yes, I have Blue dots, SST lines, HH pads, Arashi wave rotors and OEM master. I have not commented as I have no good reference that I think would help in the discussion. When I changed over it was a night and day difference, but considering that I changed nearly the entire front end at once. In addition to the above I also put on 89' fork lowers, new fork bushings and seals, RPM vales, straight rate springs, RPM fork brace. So it is no wonder it felt totally different, it was. My brake feel at the lever is stiffer, I feel like it needs less travel to apply the same amount of braking force. Is it from the SST lines? The HH pads, rotors? I have to imagine all the above contribute to the new stiffer feel. I like the stiffer feel and hesitate to try a 14mm master because I am used to the new feel of my brakes. I feel that I have good control over modulation of braking force without any over braking, even in corners when I enter a little too hot for comfort. I am not knocking the 14mm as I have no comparison, perhaps I will get bored and pull out the 14mm master and give it try. The problem is, when I get bored I suit and go for a ride. If we had an off season for riding in SoCal these projects would be easier to plan. So I hope this helps in some way.
Now back to your regular programming.... :bye2:
Quote from: FJmonkey on March 19, 2014, 11:27:14 PM
When I changed over it was a night and day difference, but considering that I changed nearly the entire front end at once. So it is no wonder it felt totally different, it was. My brake feel at the lever is stiffer, I feel like it needs less travel to apply the same amount of braking force. Is it from the SST lines? The HH pads, rotors? I have to imagine all the above contribute to the new stiffer feel. I like the stiffer feel and hesitate to try a 14mm master because I am used to the new feel of my brakes. I feel that I have good control over modulation of braking force without any over braking, even in corners when I enter a little too hot for comfort. I am not knocking the 14mm as I have no comparison, perhaps I will get bored and pull out the 14mm master and give it try. So I hope this helps in some way.
That's great feedback Mark! On the first point, you noticed a great improvement in handling and braking, but as you say...you changed out a LOT of components! On the other point, you noticed less brake lever throw with the new calipers and keeping the stock M/C. That aligns with the new hydraulic scheme. You have the OEM ~16mm master moving more fluid than the R1 Calipers...with their smaller piston area...need. That leads to a shorter throw and a "harder" lever feel. Based on the great info in the link that Pat provided, lever feel/modulation can be altered by M/C choice and is a personal preference.
Mind you, I'm not trying to be talked into...or out of...changing to blue dots over my OEM setup. I'm perfectly happy with the braking performance of my bike. That may well be because I've changed to all SS lines, a new OEM M/C, did a proper service on the calipers, fresh pads, fresh fluid and an anal-retentive bleeding job on the front end. I just like to understand things and if someone comes along with something more solid on the blue dot calipers than "way better than my old setup", I might just look into a pair for an improvement in braking I'm not even imagining at this point. Until then...for me anyway...the blue dots are a solution for which there is no problem.
Cap'n Ron. . .
Quote from: FJmonkey on March 19, 2014, 11:27:14 PM
Quote from: movenon on March 19, 2014, 08:49:45 PM
Talk to Mark, I think he is, or was running a stock 5/8 MC with the blue dots.
George, if you mean me as the Mark you refer to then yes, I have Blue dots, SST lines, HH pads, Arashi wave rotors and OEM master. I have not commented as I have no good reference that I think would help in the discussion. When I changed over it was a night and day difference, but considering that I changed nearly the entire front end at once. In addition to the above I also put on 89' fork lowers, new fork bushings and seals, RPM vales, straight rate springs, RPM fork brace. So it is no wonder it felt totally different, it was. My brake feel at the lever is stiffer, I feel like it needs less travel to apply the same amount of braking force. Is it from the SST lines? The HH pads, rotors? I have to imagine all the above contribute to the new stiffer feel. I like the stiffer feel and hesitate to try a 14mm master because I am used to the new feel of my brakes. I feel that I have good control over modulation of braking force without any over braking, even in corners when I enter a little too hot for comfort. I am not knocking the 14mm as I have no comparison, perhaps I will get bored and pull out the 14mm master and give it try. The problem is, when I get bored I suit and go for a ride. If we had an off season for riding in SoCal these projects would be easier to plan. So I hope this helps in some way.
Now back to your regular programming.... :bye2:
Yes I did mean you, and the input is helpful. I am going to use the stock MC to start with and when I come across a good deal on one of the 14mm GL 1800 MC 's I will go for that. Wish we could ride year around up here. The colder weather is a show stopper. And when the weather starts to clear up you have to contend with rain and sand plus a few pot holes........
George
In that case, I am happy to have helped. Just to make one thing clear, the stiffer feel does not mean I need to squeeze harder to stop. I can lock up the front with only two fingers, not something I felt I could do with the 86' OEM setup.
Quote from: FJmonkey on March 20, 2014, 12:58:44 AM
In that case, I am happy to have helped. Just to make one thing clear, the stiffer feel does not mean I need to squeeze harder to stop. I can lock up the front with only two fingers, not something I felt I could do with the 86' OEM setup.
Do you still have your '86 calipers? I'd love to get a look at those...
Cap'n Ron. . .
Quote from: Capn Ron on March 19, 2014, 07:38:16 PM
Just funneling in some more data...Not sure if this has been posted somewhere over the years, but I have a spare set of '92 front calipers in the stockpile so I did some measuring........
Cap'n Ron. . .
I suspect not.
Quote from: Pat Conlon on March 19, 2014, 06:07:35 PM
......... but fear not, Noel will chime in shortly. (popcorn)
I hate to disappoint you Pat, but sometimes it's better just to sit back and watch. A lot of people are enjoying this thread.
Noel
Quote from: movenon on March 19, 2014, 08:49:45 PM
"So far, all I can find on the blue dots shows the weight to be 720 grams?? shok Sheesh, that's getting near a pound of unsprung weight savings per caliper! The gold dots with the aluminum pistons are listed at 650 grams each...well over a pound savings each over OEM. Not bad at all!"
On the weight issue, I also found that the Race Tech springs also take some weight out of the system. My FJ calipers weighed in at 1.065 kg each with pads. Not a big thing but it all adds up. I imagine aftermarket rotors are also lighter.
Talk to Mark, I think he is, or was running a stock 5/8 MC with the blue dots.
Good information Ron. Keep up the flow :good2:
George
George or Cap'n Ron, can you find out the total unsprung weight of the front end (someone must have one in bits) Forks, wheel, discs, calipers (applied), tyre (inflated to max pressure) mudguard etc.
Thanks
Noel
Quote from: ribbert on March 20, 2014, 04:09:56 AM
George or Cap'n Ron, can you find out the total unsprung weight of the front end (someone must have one in bits) Forks, wheel, discs, calipers (applied), tyre (inflated to max pressure) mudguard etc.
Thanks
Noel
That's a fun question...I have two full sets of OEM wheels hanging around with tires and rotors mounted that would be easy to weigh out, but there would be variations in weight based on tire choice...I would certainly be splitting hairs over the weight of air pressure. I have already given OEM caliper weights with brake pads (new or worn?)... I have spare front fender halves lying around (pretty insignificant in the grand scheme, I'm sure)...Then there's the unsprung part of the front forks? How much of the spring do you consider "unsprung"? How much of a brake line do you weigh figuring one end is attached to an unsprung part and the other end is attached to a sprung part? What about the speedo cable? Are you looking to get accurate numbers or just a ballpark estimate?
I'm certainly not going to change calipers for a weight savings alone...but if there IS a yet-to-be-clarified improvement in clamping force to be realized with the blue dots, a weight savings just goes into the "pros" side of the pros/cons list.
I guess I'm saying that I can weigh out some of these things easily...but being completely accurate with unsprung weight will be difficult, so I can't furnish the full, accurate answer. Still want rough numbers?
Cap'n Ron. . .
Quote from: Capn Ron on March 20, 2014, 04:59:59 AM
Quote from: ribbert on March 20, 2014, 04:09:56 AM
George or Cap'n Ron, can you find out the total unsprung weight of the front end (someone must have one in bits) Forks, wheel, discs, calipers (applied), tyre (inflated to max pressure) mudguard etc.
Thanks
Noel
That's a fun question...I have two full sets of OEM wheels hanging around with tires and rotors mounted that would be easy to weigh out, but there would be variations in weight based on tire choice...I would certainly be splitting hairs over the weight of air pressure. I have already given OEM caliper weights with brake pads (new or worn?)... I have spare front fender halves lying around (pretty insignificant in the grand scheme, I'm sure)...Then there's the unsprung part of the front forks? How much of the spring do you consider "unsprung"? How much of a brake line do you weigh figuring one end is attached to an unsprung part and the other end is attached to a sprung part? What about the speedo cable? Are you looking to get accurate numbers or just a ballpark estimate?
I'm certainly not going to change calipers for a weight savings alone...but if there IS a yet-to-be-clarified improvement in clamping force to be realized with the blue dots, a weight savings just goes into the "pros" side of the pros/cons list.
I guess I'm saying that I can weigh out some of these things easily...but being completely accurate with unsprung weight will be difficult, so I can't furnish the full, accurate answer. Still want rough numbers?
Cap'n Ron. . .
Rough is fine, which I know in you case will be a very fine rough.
Noel
I have switched over to the blue dots and master cylinder from a 2005 FJR 1300. I took off the old brake system intact, the new system came intact as well. I weighed both systems with a digital scale and was shocked at how little less the new system weighed in comparison. Did I write down the numbers :dash1:? I may pull the new one off this weekend just to check..... Anyway, I am using the OEM rubber brake hoses and what appears to be OEM brake pads on the original FJ rotors. I feel that there was a significant ( not dramatic) improvement over the original brakes. Considering all that has really changed in my case was M/C diameter and piston diameters (and caliper construction), It just seems to me that the M/C to caliper area ratio is simply better matched to the human hand. I now never use more than 2 fingers to get all the stopping force that the Avon Storm will take. I commonly used 3 or 4 fingers on the lever before the change.
While we are discussing brakes, has anyone used the Venhill brake lines? The prices are very attractive, but the idea of brake hoses that you screw together is a little shakey in my mind. I know they are TUV approved and approved in the UK, so there had to be some testing to get those certifications. I'm just asking for any personal experiences.
Joe
Quote from: Country Joe on March 20, 2014, 06:13:41 AM
While we are discussing brakes, has anyone used the Venhill brake lines? The prices are very attractive, but the idea of brake hoses that you screw together is a little shakey in my mind. I know they are TUV approved and approved in the UK, so there had to be some testing to get those certifications. I'm just asking for any personal experiences.
Joe
Why? Your entire bike is held together with threads and it is a threaded connection that holds the banjo in and the calipers on and how they are joined on you car ...... That connection is no more likely to fail than any other.
Yes, they are very well priced and I had to change mine over (from Australia) and they did so without complaint and I only paid the return postage. The ones they recommend for for the FJ were miles to long.
(http://farm9.staticflickr.com/8198/8201727489_c9ef6eb6d5_c.jpg)
Mine see a lot of dirt roads (corrugations and the like) and get a lot of flexing. These have done a lot of miles.
What ever you choose it is important to have adjustable banjos.
(http://farm8.staticflickr.com/7338/12144183003_ef8d4200ab_c.jpg)
They also get a lot of hard use and repeated near full compression of the forks which is a lot of flexing. I have them clamped where the splitter was which is probably a bit tight and has them bending more than is ideal but there is no sign of fatigue.
Yep, I'd recommend them. The general feel when handling them is that of a quality product, good finish, good plating, good hardware. Nothing looks or feels cheap about them.
While people like using words such as Speigler, Galfer and Brembo when referring to their bikes, I don't really think premium brake lines are anything more than marketing hype.
I can feel it in by bones, someone will disagree with me!
Noel
Noel,
Thanks for the feedback on the Venhill lines. I agree that having adjustability on the banjo fittings is a good thing. I have all the lengths measured out for the lines that I need to replace. I need to quit dragging my feet and pull the trigger on the order. I think I have everything for the GSXR rear wheel swap except for the brake hose. It is way past time for this swap to be completed.
Totally agree with you Noel. the ship I work on has dozens of Hydraulic hoses, factory hydraulics, deck equipment, cranes, steering system,propellar shaft brakes, membrane hoses on reverse osmosis watermaker. I make all the hoses in house with re-usable threaded hose fittings. I see numerous hose failures but never at the threaded connection. Almost all failures are due to chaffing on something else.
Scott
Observations,theories,musings and maybe a few facts.
Facts. piston dia. monoblock. 30.2 and 27.mm
89-93 2 piece. 32.1 mm.
weight difference 130. gm. in favour of the monoblock per caliper
Observations. I got rid of my 86FJ in 98 and replaced it with a 93 at the same time. In both cases the brakes were in good condition and had stock pads and hoses and fresh fluid no sticking pistons. The 93 brakes were a definete improvement. Fast forward to 08. The abs system died and I decided to remove it and do some upgrades at the same time. Ditch the stock abs wheels new brake lines, pads etc. Rounded up a 17"600r rear wheel, Fzr front, 14mm. m/c etc. I already had some R1 calipers and had popped the pistons and replaced the seals plus had new pads ready. Did the wheel swap including new front rotors, Chinese Galfer knockoffs. The original calipers were gone through also with fresh pads, same brand and compound and were reinstalled along with the original 5/8 m/c. I made up some screw together braided lines and reinstalled a stock brake system with upgraded pads, braided lines, new rotors, calipers in perfect condtion and fresh dot4. The system was bled and the pads and rotors bedded in. Was there an improvement? Yes, not dramatic but a definite improvement. Next came the R1 calipers, rebuilt and same brand and compound pads. Was there another incremental improvement? No, I couldn't sense much difference. Next the 14mm. m/c. Big change, a bit more lever travel, much better modulation and less effort. I realize this has been gone over a multitude of times but I thought I'd offer it in the order I did it and show my observations. Now comes the speculation part. Since the original question by Jeff dealt with improving the braking performance on his 87 I wonder if the 14mm.m/c would improve the two piston system in terms of feel and modulation.
I bought another 93 FJ recently which still has stock brakes. I tried very hard squeezing as hard as I could but could not get any flex nor swelling of the calipers. Ed, I'm not saying you did not observe this but I could not duplicate this. Perhaps as Noel mentioned you had one or more sticking pistons and the movement you noticed was was the flexing at the mounting points cased by this reason. I've observed this on my gen.2 FZ1 when I had a sticking piston.Looking back I should have tried tried the 14mm. m/c with the original 2 piece calipers as a direct comparison to the monoblocks but I didn't so perhaps If I don't sell my extra FJ I might toss a 14mm. m/c at it and see what the results are like with the stock calipers.
Noel, your contention that a variable leverage m/c is a better way to go than the correct size unit is interesting, untill you price out one of these units. You still have to size out the m/c for the particular application and then fine tune it to your own taste. At the high end of the scale a very nice Brembo fully adjustable billet unit used by bucks up racers can set you back close to $3,000 ca.Reservoir,banjo bolt and washers not included. In theory a radial pump m/c does offer advantages. I'm sure guys like Marques, Pedrosa and Lorenzo are somewhat fussy when it comes down to braking components but for an average street rider the answer is not as clearcut.
I should leave well enough alone on the subject of dot4 versus 5 but I can't help it. Back in 78 HD started using dot5, then in about 08 with the introduction of abs on their bikes they reverted back to dot4. This is an observation and I draw no conclusion from this.
Note to Pat, Unless I'm wrong I believe that both the 16 and 17 FJ wheels were 3" wide but your right the 16 is pig heavy.
No oil comments, Hein
Quote from: ribbert on March 20, 2014, 06:01:43 AM
Quote from: Capn Ron on March 20, 2014, 04:59:59 AM
Quote from: ribbert on March 20, 2014, 04:09:56 AM
George or Cap'n Ron, can you find out the total unsprung weight of the front end (someone must have one in bits) Forks, wheel, discs, calipers (applied), tyre (inflated to max pressure) mudguard etc.
Thanks
Noel
I guess I'm saying that I can weigh out some of these things easily...but being completely accurate with unsprung weight will be difficult, so I can't furnish the full, accurate answer. Still want rough numbers?
Cap'n Ron. . .
Rough is fine, which I know in you case will be a very fine rough.
Noel
Here you go...
Disclaimers:
* This is a 1992 FJ1200 ABS model
* I directly weighed everything except the lower fork tubes...I took a WAG (Wild Ass Guess) at 5 lbs each.
* I took the average weight of a new Metzeller ME880 tire and a new Sport Demon tire in the stock 120/70-17.
* I cut the spring weight in half as technically, only half is "unsprung".
* I did not include the RPM fork brace which is on my bike, but isn't OEM.
* I didn't include the reflectors or the speedometer cable.
(http://fjowners.com/gallery/7/697_20_03_14_2_46_31.bmp)
File under "too much time on my hands" :yes:
Cap'n Ron. . .
Quote from: ribbert on March 20, 2014, 07:24:24 AM
While people like using words such as Speigler, Galfer and Brembo when referring to their bikes, I don't really think premium brake lines are anything more than marketing hype.
I can feel it in by bones, someone will disagree with me!
Noel
I completely agree. I used Galfer lines because they're around 20 miles from my house. There wasn't an ABS "kit" available from anyone, so I worked with them during my rebuild to duplicate all the lines required. This took several trips back and forth to get things just right...When all was said and done, one of the lines leaked at the banjo fitting so back I went. They knocked out a new one in a few minutes and all was good, but it drives home the point that if you have a bulk reel of SS brake line, a bin full of banjo fittings and a crimp press, any monkey could knock these things out! (No offense Mark) :biggrin:
Cap'n Ron. . .
That's great information Ron 69.16lbs is a lot. I wasn't much help in weighing things. I have a front wheel with a tire on it but no rotor and the wheel on the bike is a 87/88 FZR.
So the biggest gain in reducing the wieght would probably be evalution of a another front wheel and rotors. Somewhere I seen the FZR wheel weight. I will do some digging. Good facts for the camp fire Ron.
George
SimiEd PM'd me with a good suggestion to test the flex of the calipers. This did interrupt my busy schedule of sitting, but off I went to measure the flex. :good2:
I wasn't sure what to expect or what I was hoping to find other than some accurate number.
The setup:
(http://fjowners.com/gallery/7/697_20_03_14_3_42_28_0.jpeg)
I attached the dial indicator base to the rotor just below the caliper. I then aligned the dial indicator tip to the piece of flashing just below and between the two pots. This was as far away from the clamping bolts as possible to try to realize the most movement.
I then zeroed out the dial to make readings easier:
(http://fjowners.com/gallery/7/697_20_03_14_3_42_29_1.jpeg)
I then squeezed (squoze?) the front brake lever as hard as I could and noted the deflection of the dial:
(http://fjowners.com/gallery/7/697_20_03_14_3_42_29_2.jpeg)
Good lord, I thought I was going to snap the brake lever and I was reading .005" of flex. That's "five thousandths" of an inch. I repeated this several times and adjusted the markers on the dial face. I couldn't get the needle to swing any farther than what you see above. If I'm being honest, the needle start point was a smidgeon off the "zero" and it never quite touched the fifth line making the delta more like .0045".
To put things in perspective, that's less than the thickness of this piece of paper:
(http://fjowners.com/gallery/7/697_20_03_14_3_42_29_3.jpeg)
To be fair, I would just have to assume the other side of the caliper flexes the same amount for a total of ten-thousandths of an inch. I don't have a blue dot setup around to measure the flex of those and compare, but ten-thousandths seems like a scant amount of flex in the OEM setup. Or am I way off here and that's a HUGE amount of flex for a caliper? :scratch_one-s_head:
Cap'n Ron. . .
Quote from: movenon on March 20, 2014, 05:01:59 PM
That's great information Ron 69.16lbs is a lot. I wasn't much help in weighing things. I have a front wheel with a tire on it but no rotor and the wheel on the bike is a 87/88 FZR.
So the biggest gain in reducing the wieght would probably be evalution of a another front wheel and rotors. Somewhere I seen the FZR wheel weight. I will do some digging. Good facts for the camp fire Ron.
George
Hey George,
After reading your reply, I realized that I initially weighed the entire front wheel WITH tire and rotors at 29lbs. Then I weighed loose tires and removed a rotor to weigh it, but forgot to subtract them from the wheel weight. Here are the correct weights:
(http://fjowners.com/gallery/7/697_20_03_14_4_29_10.bmp)
So...the wheel itself is just under 10lbs, but the rotating mass (wheel, tire and both rotors is 29 lbs).
Cap'n Ron. . .
Quote from: Capn Ron on March 20, 2014, 04:03:05 PM
Here you go...
(http://fjowners.com/gallery/7/697_20_03_14_2_46_31.bmp)
File under "too much time on my hands" :yes:
Cap'n Ron. . .
That is fantastic, thanks Cap'n. But it gives rise to an even more perplexing question. How do go sailing (on your own yacht) get to ride all over the country AND have this much time? Time poor FJ'er needs to know.
It is interesting when you think of the speed and frequency that this weight (approx 1/3 of body weight) needs to be pushed back onto the road to maintain contact when travelling fast.
I believe MotoGP bikes lose up to 10% of their power down a main straight through the suspensions inability to keep the wheel planted.
There are certain roads and speeds where I have experienced this on the FJ, to the point of hearing and feeling it, but I suspect it has more to do with crappy suspension than 250hp/300kph.
Those fortuneate enough to live in the stratosphere of motorbike mods where money is no object and can afford composite wheels ( around $3000 a set) claim a transformation like no other to the bikes handling. Something I will never get the opportunity to have an opinion on.
Thanks again Cap'n, I will file that info into the data bank.
Noel
Quote from: Capn Ron on March 20, 2014, 05:16:14 PM
SimiEd PM'd me with a good suggestion to test the flex of the calipers. This did interrupt my busy schedule of sitting, but off I went to measure the flex. :good2:
I wasn't sure what to expect or what I was hoping to find other than some accurate number.
Cap'n Ron. . .
Cap'n, the real figure is likely less. You should measure it with no more pressure than required to lock the wheel, a couple of fingers worth. In reality, even that would be an exaggerated figure because nearly all braking done with road use is at way less than max. Very hard road riding is probably only going to see 75% of that.
It also remains possible that all or some of that measurement is disc flex.
Noel
I am of the opinion this is a HUGE amount of flex. Even if you're getting 1/2 of the total, 0.005", that's' probably 2-3x the pad movement. Consider how much clearance is there typically between a brake pad & rotor? My guess is ... 0.001" to 0.002" maximum. We've all had to pump up the brakes after pad replacement, then the new pads will squeal because they're riding the rotor. How about (extreme example, granted) the MotoGP guys that will blow a corner and run off the track after a headshake incident causes the pads to retract?
I also disagree that this an extreme amount of pressure. Now, I haven't seen Ron in several years, but as I remember he did have little girly-man hands, so his claim of " squeeze as hard as he can" is a bit dubious! :praising: (Ron, just kidding!) I typically ride 2 up and use a lot of front brake and 0 rear brake. Maybe that's why I noticed such a huge improvement.
Now, I'd measure the clearance between the pads & rotors, but my FJ is still doing the snowbird thing in Modesto, so I have no real point of reference.
(this is me doing my "no bike, I'm bored" shit-stirring :mail1: )
Ron. are you still free? :bomb:
I agree with Noel's statement about flex, but the rotor should be held steady by the opposed pistons. I have noticed caliper flex after a rebuild of a stock rear caliper. There was some excess fluid that I could see in the line where the two caliper halves join. When pressing the rear pedal, I could see very slight movement in the fluid between the halves. I'm sure it's not a big contributor in the performance difference. I suspect most people want to see this increase more than they are really experiencing it. They are also probably replacing worn out components with much fresher components.
Ron,
You had the same thought that I did, as far as checking flex of the calipers. I guess I can do a flex check of a blue dot caliper. Honestly, I don't think .010 flex is much at all.
George,
My FZR wheel just got delivered by the FedEx man today, I will hang it on my digital scale as soon as I get back home. It looks like Wills Rim Repair did a bang up job in straightening the pothole dent. t
Quote from: FJ_Hooligan on March 20, 2014, 06:14:56 PM
.....but the rotor should be held steady by the opposed pistons.
That's assuming a 100% equal
initial force by the pistons. A few thou initial deflection in the disc doesn't take much and with a dial indicator on one side only it's possible that as more force was applied and the pistons centred, the disc move back to it's resting position.
The fact these are floating discs may well account for some movement too, both visual and as a mount for measuring.
I can't believe I got sucked into this again.
No more.
I'm more fascinated by Arnie and CanDmans hair at the moment.
Noel
Quote from: ribbert on March 20, 2014, 06:00:08 PM
Cap'n, the real figure is likely less. You should measure it with no more pressure than required to lock the wheel, a couple of fingers worth. In reality, even that would be an exaggerated figure because nearly all braking done with road use is at way less than max. Very hard road riding is probably only going to see 75% of that.
It also remains possible that all or some of that measurement is disc flex.
Noel
Yeah Noel, that's exactly right. The flex in the real world would be FAR less as I was applying a *ridiculous* amount of lever force! My only purpose in going to the extreme was to establish a baseline of maximum flex of the OEM caliper in the worst case scenario. Which really isn't a riding or braking scenario at all...just how much stiffer might the blue dot calipers be in the same worst case scenario.
When FJMonkey gets back stateside, I might be able to talk him into letting me do the same test to his blue dots...then we might get a handle on a possible difference in stiffness between the two.
Any perceived "naked eye" flex would have to be the rotor flexing...at least part of it anyway. I'd be hard pressed to believe anyone could feel less than .005" of measured caliper movement by hand. In this test anyway, I'm discarding the disc flex variable as I'm mounting the dial indicator to the disc itself. The measurement remaining after the pads contact the rotor is the just the flex of the caliper.
Cap'n Ron. . .
Quote from: Country Joe on March 20, 2014, 06:24:57 PM
Ron,
You had the same thought that I did, as far as checking flex of the calipers. I guess I can do a flex check of a blue dot caliper. Honestly, I don't think .010 flex is much at all.
Yeah, I'm with you on this one. The other factor is that even with that tiny amount of flex at the near breaking point of the lever (or so it felt), the lever still had another inch before it hit the grip. It's as if the caliper will flex a tiny amount and then stop flexing...even as more force is applied. That would seem like the .010" of flex may add a tiny bit of "sponginess" to the system, but shouldn't limit it's ability to clamp the pads to the rotor.
Cap'n Ron. . .
Quote from: simi_ed on March 20, 2014, 06:09:33 PM
I am of the opinion this is a HUGE amount of flex. Even if you're getting 1/2 of the total, 0.005", that's' probably 2-3x the pad movement. Consider how much clearance is there typically between a brake pad & rotor? My guess is ... 0.001" to 0.002" maximum. We've all had to pump up the brakes after pad replacement, then the new pads will squeal because they're riding the rotor. How about (extreme example, granted) the MotoGP guys that will blow a corner and run off the track after a headshake incident causes the pads to retract?
I also disagree that this an extreme amount of pressure. Now, I haven't seen Ron in several years, but as I remember he did have little girly-man hands, so his claim of " squeeze as hard as he can" is a bit dubious! :praising: (Ron, just kidding!) I typically ride 2 up and use a lot of front brake and 0 rear brake. Maybe that's why I noticed such a huge improvement.
Now, I'd measure the clearance between the pads & rotors, but my FJ is still doing the snowbird thing in Modesto, so I have no real point of reference.
(this is me doing my "no bike, I'm bored" shit-stirring :mail1: )
Ron. are you still free? :bomb:
I'm with Noel at this point...I'm stepping out of this discussion until I can possibly measure a blue dot setup...until then, there's just a lot of supposition. "No decision is difficult once you have all the facts." I hope my input has helped some.
Cap'n Ron. . .
Quote from: Capn Ron on March 20, 2014, 05:16:14 PM
SimiEd PM'd me with a good suggestion to test the flex of the calipers. This did interrupt my busy schedule of sitting, but off I went to measure the flex. :good2:
I wasn't sure what to expect or what I was hoping to find other than some accurate number.
The setup:
(http://fjowners.com/gallery/7/697_20_03_14_3_42_28_0.jpeg)
I attached the dial indicator base to the rotor just below the caliper. I then aligned the dial indicator tip to the piece of flashing just below and between the two pots. This was as far away from the clamping bolts as possible to try to realize the most movement.
I then zeroed out the dial to make readings easier:
(http://fjowners.com/gallery/7/697_20_03_14_3_42_29_1.jpeg)
I then squeezed (squoze?) the front brake lever as hard as I could and noted the deflection of the dial:
(http://fjowners.com/gallery/7/697_20_03_14_3_42_29_2.jpeg)
Good lord, I thought I was going to snap the brake lever and I was reading .005" of flex. That's "five thousandths" of an inch. I repeated this several times and adjusted the markers on the dial face. I couldn't get the needle to swing any farther than what you see above. If I'm being honest, the needle start point was a smidgeon off the "zero" and it never quite touched the fifth line making the delta more like .0045".
To put things in perspective, that's less than the thickness of this piece of paper:
(http://fjowners.com/gallery/7/697_20_03_14_3_42_29_3.jpeg)
To be fair, I would just have to assume the other side of the caliper flexes the same amount for a total of ten-thousandths of an inch. I don't have a blue dot setup around to measure the flex of those and compare, but ten-thousandths seems like a scant amount of flex in the OEM setup. Or am I way off here and that's a HUGE amount of flex for a caliper? :scratch_one-s_head:
Cap'n Ron. . .
If you want to determine caliper flex should you not place the dial base on the floating rotor? I would think to get a true measurement of caliper flex the base should be fixed to something independent of the floating rotor...like the fork maybe?
I understand the mag base wont work on the lower fork but if you hose clamp the base around the fork and close to the caliper bracket as possible id bet you would get a much different and better representation of caliper flex.
lets get some more sticks on this horse, hes still movin!
I like my Blue Dots...they look cool
Scott
Quote from: movenon on March 20, 2014, 05:01:59 PM
That's great information Ron 69.16lbs is a lot. I wasn't much help in weighing things. I have a front wheel with a tire on it but no rotor and the wheel on the bike is a 87/88 FZR.
So the biggest gain in reducing the wieght would probably be evalution of a another front wheel and rotors. Somewhere I seen the FZR wheel weight. I will do some digging. Good facts for the camp fire Ron.
George
George,
I just weighed my FZR 1000 wheel without rotors but with bearings and center bearing spacer. I came up with 11.4 lbs.
Joe
Threads that go on for too long tend to go in strange tangents and this one is no different. From improving a 87 brake system we've gone to weighing fork components, which is at least usefull, to testing caliper deflection using a flawed and thus useless method.
Look for the elephant in the room. Its called the FJ fork assembly, complete with wheel and calipers. Its a long 41mm. damper rod fork cursed with a pencil dick 15 mm. axle and today would be considered suitable for a small displacement budget oriented entry level bike. If .005 deviation worries you do a dynamic deviation test on these forks, you won't need a dial indicator, a tape measure would be more suitable. The amount of movement in these forks will scare the crap out of you.
If you still want to test both styles of calipers for flex or swelling remove them from the forks and test them on their own.
Hein.
Is this the digital campfire way of saying "How about them Packers...? :dash2:
You're right Hein...Sorry I bothered...
yup!
To Ed and Ron
If I offended you I apologize, that was not my intent, neither did I say that a comparitive deflection test of the two different calipers was a waste of time. My intent was to show that a flexible reference point from which to measure was flawed. If I havn't bored the crap out of you please reread the last part of my post. Remove the caliper from the fork and test them on their own.
Hein.
Quote from: hein on March 21, 2014, 03:16:14 PM
To Ed and Ron
If I offended you I apologize, that was not my intent, neither did I say that a comparitive deflection test of the two different calipers was a waste of time. My intent was to show that a flexible reference point from which to measure was flawed. If I havn't bored the crap out of you please reread the last part of my post. Remove the caliper from the fork and test them on their own.
Hein.
Hein...Thanks for that. I definitely don't have the answers and really enjoy the process of figuring things out. Sometimes that leads to a circuitous path in a thread. Probably should have opened up a new thread for unsprung weight. I am gaining a better understanding on the brake system...an area I've never had a need to dig into.
After re-reading Noel's and Scott's replies about a flexing rotor, I pondered this in the garage for a bit last night. I tried to mount the dial indicator to read the inside half of the caliper, but it's just too crowded. I took a break from it and watched some show on the tube and then wondered if just pulling the two caliper bolts from the fork (as you're suggesting) would do the trick. Makes sense to me to isolate things. I may have been re-inspired. :good2:
Cap'n Ron. . .
Ron
Now that we've got our differences worked out maybe I can point out a way of testing the calipers. Removing just the caliper bolts will not help because now you have another moving reference point. One way would be to bolt the caliper to a chunk of aluminum mounted on a stable surface, milling machine bed comes to mind, then slip either a disc or a piece of steel the same thickness between the pads, hook up a m/c to this and using two dial indicators apply pressure and scan both sides of the caliper to check for deviation. This would get a bit complicated and time consuming. Another easier way might be to remove the rotor bolts so that the engagement part of the rotor would not have any tension from the wheel hub. Hooking up one or two dial indicators in this configuration will be a bitch.
The problem with you first method was that you assumed the caliper was at fault. Its like measuring for crankshaft runout and finding it exessive that you assume the crank is at fault. It could be a bearing or bearing bore thats bad. I've spent a good part of my working life diagnosing and measuring stuff and still end up walking down the wrong street.
Hein.
Spindly 41mm fork tubes and a pencil dick 15mm axle.....I just spit coffee on my keyboard...I hate that...
:lol:
I'm humbled :hi: and now convinced of disc side flex.
Hein,
I too thought that having a dial indicator on both sides of a caliper would be the best way of measuring, but as you said...that would be exceedingly difficult as I have just one dial indicator and about six other hobbies that need my attention (trying to get my rock crawler finished in time for Moab in three weeks :shok:). Given that, I re-set up the dial indicator attached to the rotor and detached the caliper from the fork allowing it to "float". Sure enough...it made a difference. Where I was reading .0045" of flex yesterday, I'm now reading about half of that. I'm calling it at .0025"...So, to some degree the caliper being fixed to the fork essentially "pulls" the rotor a bit to one side. Re-attaching the caliper to the forks, I'm again reading very near the original .0045"
That's close enough for me to compare to a blue dot caliper when I have access to one.
Cap'n Ron. . .
Ron
Remove rotor bolts to elimate some disc flex out of the equation.
Hein.
Quote from: hein on March 21, 2014, 04:28:52 PM
Ron
Remove rotor bolts to elimate some disc flex out of the equation.
Hein.
Someone once told me, "Don't let 'perfection' get in the way of 'good enough'." I clearly struggle with this...probably why he thought it was appropriate to tell me that. :yes:
In this case, I think I'm at "good enough" for what we're trying to solve. On the perfection front, you're the kind of machinist that I would want working on my engines. :good2:
For now, I'm spending the rest of the weekend under the rock crawler and riding the FJ to the Lancaster air show.
Cap'n Ron. . .
Seeing as how it was my suggestion that started all this perhaps I can bring it to a conclusion with this pearl.
"The reason they are marked 1.....5 is that it indicates the number of fingers you brake with. So, if you brake with two fingers, turn it to "2" and so on"
It's from a motorbike forum, so it must be true.
While some people are having a bit of fun with this discussion and the findings are interesting, I can't help but feel it is largely fuelled by cabin fever and the onset of the Northern riding season will see these types of threads consigned to the darkest corners of the forum until next Winter.
Strangely enough I look forward to our Southern Autumn/Winter as my favourite riding season. I don't like riding in the heat, but our Winters are not as savage as most of you are experiencing.
Noel