Hi All,
What is the difference between the OEM disc rotors?
Are they all the same and can the left be swapped with the right?
I have noticed the direction arrow and numbers, mine are 47A & 47B, all stamped on the outside as far as I could see.
B's are right and A's are left.
If I used a right disc and used it on the "left" and left the rotation arrow on the inside it seems to be the same but is it?
My reason is I can get only NOS right disc's.
Cheers Alan
Alan, my take on the difference between right and left, the directional angling of of the ventilation finning is opposite. That's my recollection from when I still had the misfortune of having standard rotors and callipers. That was quite a while ago so don't take it as a given.
Regards, Pete.
PS. I do recall using a front rotor on the rear, from the opposite side that Yamaha recommends. I had not problems with it at all.
Quote from: oldktmdude on September 25, 2017, 05:20:17 AM
when I still had the misfortune of having standard rotors and callipers.
That's a bit harsh Pete :dash2:
I'm a bit hurt now :sorry:
I've had no problems stopping and those red light camera's do test your emergency braking out regularly.
They do look the same except for the direction arrow.
Cheers Alan
Alan, look at the angling of the cooling vents between the discs. Turn the right hand side around as to simulate it being mounted on the left hand side and compare the direction of the cooling fins. I think you'll find they are facing opposite directions.
Once you have 320mm rotors, blue spots, EBC HH pads and a 14mm R1 master cylinder, the OEM brakes feel like absolute shit. Try mine in December and see what I mean. :good2:
If I turned it around I would have reversed rotation and the cooling although I reckon the cooling fins are angled the wrong way but I'm no engineer.
I was actually thinking of not turning it around but mounting it with the outside facing in, exactly as if you just moved it from right to left with no turning
Cheers Alan
You can buy two new aftermarket rotors for the price of one OEM and new rotors are supposedly better. RPM has them and there are other sources. I bought mine through a local bike shop before I knew about RPM as a source for parts. I'm hanging on the two OEM fronts in case the rear ever needs replacement.
I have ordered brake components from this seller in the past. Take a look at these rotors.
http://www.ebay.com/itm/Front-Brake-Disc-Rotor-x2-Fit-YAMAHA-FJ-1100-1984-1985-84-85-/352138310700?fits=Model%3AFJ1100&hash=item51fd14342c:g:BwwAAOSwrFJZyM4W&vxp=mtr (http://www.ebay.com/itm/Front-Brake-Disc-Rotor-x2-Fit-YAMAHA-FJ-1100-1984-1985-84-85-/352138310700?fits=Model%3AFJ1100&hash=item51fd14342c:g:BwwAAOSwrFJZyM4W&vxp=mtr)
Fred
I'd say your rotors look fine, why would you change them and change for the same ones?
Quote from: balky1 on September 25, 2017, 09:57:35 AM
I'd say your rotors look fine, why would you change them and change for the same ones?
Plenty of ridges Balky, just trying to keep the bike looking original
Cheers
Alan
Alan ,I think I have a set of FJ1100 Rotors hiding in my shed ,Not sure how worn they are,,If you are interested please measure your own Rotors with a set of Viner Calipers and advise how thick your Rotors are in mm,,I will then dig my FJ1100 Rotors out and see if they are any thicker / less worn than yours ,,that's if you are interested in them at all ,,cheers Phil
Thanks for the offer Phil,
I had a chance to buy some OEM but they were all right side ones that's why the post.
I will check thicknesses of both.
I've been also looking at the Metal Gear ones, they do look similar
Just thinking out aloud here, wouldn't all the ridges actually increase the braking surface area thus increasing braking performance? :scratch_one-s_head:
Cheers
Alan
Quote from: Sparky84 on September 28, 2017, 06:06:18 AM
Just thinking out aloud here, wouldn't all the ridges actually increase the braking surface area thus increasing braking performance? :scratch_one-s_head:
Cheers
Alan
Theoretically that might make sense, but in reality IMHO I wouldn't think you would notice the difference. However when you change pads you will notice less braking efficiency until they are bedded in. More so than with smoother rotors. Also the more scoring there is - the less steel on the disc - the hotter they get - the quicker they warp.
Quote from: PaulG on September 28, 2017, 09:56:35 AM]
Also the more scoring there is - the less steel on the disc - the hotter they get - the quicker they warp.
Maybe the sintered pads have scored the OEM discs :scratch_one-s_head: , I'm wondering if this is the case
Cheers Alan
I have still OEM rotors at home, will ensure if there is any offset and let you know.
As far as I remember, offset is 0, so if you do not mind to have rotation arrow on the inside, go ahead. :good2:
Quote from: wainot-Phil on September 28, 2017, 05:35:31 AM
measure your own Rotors with a set of Viner Calipers and advise how thick your Rotors are in mm
Hey Phil, finally got around to measuring them, 7.2 & 7.3.
Quote from: Bezmozek on October 01, 2017, 02:10:04 PM
I have still OEM rotors at home, will ensure if there is any offset and let you know.
As far as I remember, offset is 0, so if you do not mind to have rotation arrow on the inside, go ahead. :good2:
If that's the case No worries, as long as I fit them with the arrow the same as rotation I don't need to see it anymore.
Cheers Alan
Hi Alan , I found and measured the 2 x S/H FJ1100 Rotors that I have ,Looks like they are worn out ,They only measure about 6 to 6.1 mm ,, better off with the Rotors you have ,,cheers Phil
Quote from: oldktmdude on September 25, 2017, 06:24:12 AM
Once you have 320mm rotors, blue spots, EBC HH pads and a 14mm R1 master cylinder, the OEM brakes feel like absolute shit. Try mine in December and see what I mean. :good2:
This
how you doing Pete ?
Quote from: FJools on October 04, 2017, 11:37:26 PM
Quote from: oldktmdude on September 25, 2017, 06:24:12 AM
Once you have 320mm rotors, blue spots, EBC HH pads and a 14mm R1 master cylinder, the OEM brakes feel like absolute shit. Try mine in December and see what I mean. :good2:
This
how you doing Pete ?
G'day Jools, thought you'd dropped of the edge of the planet, been a long time.
It would be great to have you down here in December for our Manshed Day, still a bed or two up for grabs. My FJ has had a bit of work done to it since we last spoke. Won't go into it now but happy to fill you in when we see you in December. Hope you can make it.
Regards, Pete.
Quote from: oldktmdude on October 05, 2017, 05:40:10 AM
Quote from: FJools on October 04, 2017, 11:37:26 PM
Quote from: oldktmdude on September 25, 2017, 06:24:12 AM
Once you have 320mm rotors, blue spots, EBC HH pads and a 14mm R1 master cylinder, the OEM brakes feel like absolute shit. Try mine in December and see what I mean. :good2:
This
how you doing Pete ?
G'day Jools, thought you'd dropped of the edge of the planet, been a long time.
It would be great to have you down here in December for our Manshed Day, still a bed or two up for grabs. My FJ has had a bit of work done to it since we last spoke. Won't go into it now but happy to fill you in when we see you in December. Hope you can make it.
Regards, Pete.
I had !!
I'm not going to commit to anything till that bike is up and running sweet, but fingers crossed we can talk shit over a few coldies eh ?
Jools, just get it going good enough to get it down here in December. We'll make it sweet over the weekend. Even if you don't have it on the road by then, drive down in your car and either ride one of my bikes or I'm sure there are others willing to lend a spare bike.
Alan, my apologies for hi-jacking your thread.
Regards, Pete. :drinks:
Hi Alan
sorry to hijack your thread...............
Pete, refer to my other thread :good2:
No Worries Guys,
We are all in the same family. :drinks:
There is only so much that can be said about brake rotors
Cheers Alan
As long as you still have enough thickness to work with, one can resurface the disc surface with an angle grinder and an abrasive pad. Then new pads to break-in and you are down the road
Quote from: bigbore2 on November 08, 2017, 10:36:35 PM
As long as you still have enough thickness to work with, one can resurface the disc surface with an angle grinder and an abrasive pad. Then new pads to break-in and you are down the road
Angle grinder? Shouldn't it be done on a lathe?
To remove old brake pad transfer layers, I've had good results using my cordless drill and a Flex Hone brush
(http://www.brushresearch.com/images/cat2/rotors.jpg)
Spin the wheel one way, scrub, then spin the wheel the other way, scrub....leaves you with a nice cross hatched surface.
This is used for only cleaning the rotors. Not a replacement for turning your rotors on a lathe.
When changing brake pad compounds (e.g. going from organic to sintered pads or vice versa) you must remove the old material built up on the rotor (called the transfer layer) before bedding in the new pads.
Cheers laddies...
Quote from: bigbore2 on November 08, 2017, 10:36:35 PM
As long as you still have enough thickness to work with, one can resurface the disc surface with an angle grinder and an abrasive pad. Then new pads to break-in and you are down the road
"DO NOT TRY THIS AT HOME" or anywhere.
If you want to resurface your rotors this way, fine. To suggest on a public forum where someone might actually try it is not only a bad idea, it's dangerous. Removing pad material is another thing.
If you think there aren't people out there who consider a cutting/grinding wheel to be an abrasive pad, you'd be wrong. I've seen it.
Pat's on the money, cordless drill speed and a non aggressive tool that's not too senstive to angle or pressure. Not too harsh or hard. IMO an angle grinder is too fast and more likely to burnish than abrade.
There are people out there whose ignorance of all things mechanical beggars belief and there's nothing wrong with that if it's not your thing, until, they fancy the notion of having a go at a few jobs themselves, and that one sounds easy.
I wouldn't even bother commenting on this but we are talking about brakes and ripping into them with a hand held aggressive tool, possibly by a complete novice, on rotors that are only a few mm thick to start with.
IMO
Noel
Quote from: ribbert on November 09, 2017, 08:31:38 AM
"DO NOT TRY THIS AT HOME" or anywhere.
If you want to resurface your rotors this way, fine. To suggest on a public forum where someone might actually try it is not only a bad idea, it's dangerous.
There are people out there whose ignorance of all things mechanical beggars belief and there's nothing wrong with that if it's not your thing, until, they fancy the notion of having a go at a few jobs themselves
I wouldn't even bother commenting on this but we are talking about brakes and ripping into them with a hand held aggressive tool, possibly by a complete novice.
Noel
Couldn't the same reasoning also apply to those that showcase their bling, such as an automatic chain oiler, stainless steel braided brake lines, or a GPS unit? It's not a stretch to envison a mechanical novice installing items like these and having disastrous results. Either with their install or use.
Where is the line drawn for those that post for the benefit of others, but shouldn't because of it being deemed a dangerous practice by others?
Marty, do you have an angle grinder?
If you do, then you know what Noel's talking about. Those puppies spin at 7,000 rpm, along with an abrasive pad would be a bit aggressive I'd say.
Get the right tool for the right job.
Brakes are important.
Quote from: Pat Conlon on November 09, 2017, 11:17:32 AM
Get the right tool for the right job.
Exactly
(http://fjowners.com/gallery/10/1388_09_11_17_12_18_19.jpeg)
Quote from: Pat Conlon on November 09, 2017, 11:17:32 AM
Get the right tool for the right job.
Yep, See reply #5. You're welcome. (http://www.fjowners.com/index.php?topic=5356.0)
Quote from: Pat Conlon on November 09, 2017, 11:17:32 AM
Marty, do you have an angle grinder?
No, but I've spent some time using them over the years.
Quote from: FJ1100mjk on November 09, 2017, 12:27:12 PM
Quote from: Pat Conlon on November 09, 2017, 11:17:32 AM
Get the right tool for the right job.
Exactly
(http://fjowners.com/gallery/10/1388_09_11_17_12_18_19.jpeg)
So Marty, you, personally, would use this on your brake rotors?
I plan to buy one of the flex hone brushes Pat posted earlier.
Pat - you should post that in the new tools section
Quote from: Pat Conlon on November 09, 2017, 01:35:28 PM
Quote from: FJ1100mjk on November 09, 2017, 12:27:12 PM
Quote from: Pat Conlon on November 09, 2017, 11:17:32 AM
Get the right tool for the right job.
Exactly
(http://fjowners.com/gallery/10/1388_09_11_17_12_18_19.jpeg)
So Marty, you, personally, would use this on your brake rotors?
If that's all I had, then sure, I'd give it a go. Sure beats the other, more labor intensive, method that I used in the past before coming across the Flex-Hone rotor tool seven or so years ago.
My past method I will not divulge, due to fear of it not being compliant with the FJowners.com approved methods and tooling. :rofl:
Quote from: FJ1100mjk on November 09, 2017, 10:36:13 AM
Couldn't the same reasoning also apply to those that showcase their bling, such as an automatic chain oiler, stainless steel braided brake lines, or a GPS unit? It's not a stretch to envison a mechanical novice installing items like these and having disastrous results. Either with their install or use.
Where is the line drawn for those that post for the benefit of others, but shouldn't because of it being deemed a dangerous practice by others?
Where indeed?
Only a few weeks back we had someone post up about tightening clutch bolts until the spring was compressed, the bolt bottomed out and then cracked the clutch basket -
with a tension wrench! Do we suggest not using a tension wrench? No. Imagine if that had been rotor bolts or caliper bolts or banjo bolts.
You can't guard against everything. The examples you mentioned Marty, the installation of a chain oiler or GPS, like most other jobs on the bike, isn't going to kill you if done badly. I have however seen poorly routed and over clamped brake lines fail.
There are a number of things I try to consider with every post, one of them is, what's the most trouble the most mechanically challenged person to read this can get into following my advice. I do not post a lot of the stuff I do for this very reason. Suggesting an angle grinder and brake rotor in the same sentence is IMO ill advised, especially when it's not necessary. As sure as the sun coming up tomorrow there will be someone out there who will read that and take an angle grinder and cutting/grinding wheel to their rotors, and that could kill you.
I remember two occasions where owners have followed the instruction "Fill the engine with oil" literally. One of them, when buying oil, commented that while his owners book said 5 litres, he'd already put 3 times that much in and it still wasn't full!
I have seen an owner put oil so thick in his engine it sheared the drive off the oil pump when he started it. Someone had suggested it might run better on thicker oil, they just didn't say how thick. The owner thought if thick is good, thicker must be better.
I've seen a piece of water pipe used instead of a king pin on the advice of a mate and so on....
More recently, and on a lighter note, someone I know pulled over on a country road and called roadside assistance when a warning light came up on the dash of her new Audi. The bemused mechanic explained the symbol was a stylised cup of coffee, the car was telling her she had been driving for 2 hours and needed a break.
You can't draw a line nor protect everyone from themselves but common sense suggests that failed brakes are dangerous and just think when posting about the possibilities of what some mechanically inept DIYer could with that snippet of information and how he might interpret it based on the tools at hand and complete lack of knowledge. This only matters if it's potentially dangerous, if not, let 'em rip.
IMO
Noel
Holy cow! She deserves a party for not simply ignoring the light!
Hey, at least she's paying attention to her dash board..... :good2:
Driving a new $80,000 Audi and a red dash light comes on...is that a coffee cup, or an oil symbol? Yes, I know, read the owners manual..still...
It's ignoring CEL's that frosts me...
Quote from: ribbert on November 10, 2017, 08:16:50 AM
As sure as the sun coming up tomorrow there will be someone out there who will read that and take an angle grinder and cutting/grinding wheel to their rotors, and that could kill you.
No angle grinder, cutting/grinder wheel will ever touch my disc's that I would Using, only if I was making a sculpture :good:
Slight rub with wet and dry would be the closest I'd go to a grinding disc, but I do have one of those
Flex Hone Tools
Quote from: ribbert on November 10, 2017, 08:16:50 AM
I've seen a piece of water pipe used instead of a king pin on the advice of a mate and so on....
I've seen a nail used as a fuse wire, they couldn't fit it in the fuse so they removed the whole fuse and wrapped the wires to it! :dash2:
Quote from: ribbert on November 10, 2017, 08:16:50 AM
it based on the tools at hand and complete lack of knowledge.
And common sense
Cheers Alan
Brakes just slow you down. Too many snowflakes these days...
I use the "Flex-Hone" tools that Pat had posted.
I have both a medium grit one, and a coarse one.
I use them as Pat had described, in both directions. I usually use both grits also. Start with the coarse, then finish with the medium.
An electric drill is all you need, and they actually work best on the slowest speed settings.
Gentlemen, gentlemen. I knew if I posted that I would get opinions.
One of you, with an opinion, but no experience in doing this, hows about listing WHY this is a bad idea?
You say its a bad idea, but why? I have a successful application of this method, all 3 rotors on my 84 were done this way, carefully watched while breaking in, and over 15,000 mi of success on my stock setup.
I have done many sets of car brakes and understand the idea here on how brakes work.
I originally was looking for a shop who turned rotors, but could not find any who did motorcycle rotors.
A lifetime mechanic introduced me to this method many years ago as we were rebuilding a car together.
I decided to try it on my bike rotors, successfully applied to 1 dirt bike and my 84.
So I guess being successful doing this is not good enough criteria for some of you. Fine. I owe you a beer.
but please tell me why this is a bad idea. And you better be able to back up that rebuttal with something more than just an opinion....
and just to say, I love this site and the many members here. You guys crack me up sometimes.
Quote from: bigbore2 on November 11, 2017, 11:09:46 AM
One of you, with an opinion, but no experience ....
I don't need to place my bare hand into a pot of boiling water to know it's a bad idea. I know about power tools and metal. Experience? Yes, I have that - and qualifications.
Quote from: bigbore2 on November 11, 2017, 11:09:46 AM
I originally was looking for a shop who turned rotors, but could not find any who did motorcycle rotors.
The reason you couldn't find a shop to turn bike rotors is because you don't. No brake shop would do it. They are a single use consumeable, wear them down, throw them out. They are not like cast iron car rotors.
Quote from: bigbore2 on November 11, 2017, 11:09:46 AM
..... And you better be able to back up that rebuttal with something more than just an opinion....
Bigbore, if you can
uniformly remove metal over the entire surface of a rotor with a hand held tool you are indeed a legend. :biggrin:
Anyway, you have rolled two subjects into one, the merits of the procedure and the wisdom of putting it on the forum.
What you do to you own brakes is your business, my concern is limited to posting a dodgy and potentially dangerous procedure on line that someone else without your skill might try. If it was anything other than brakes I wouldn't care.
Why are you doing it the first place? Perhaps you could explain that for the "inexperienced"
As for "backing up the rebuttal with something more than just an opinion" It's not required, the folly of the procedure speaks for itself, and that's a fact.
Noel
Quote from: Pat Conlon on November 09, 2017, 01:35:28 PM
Quote from: FJ1100mjk on November 09, 2017, 12:27:12 PM
Quote from: Pat Conlon on November 09, 2017, 11:17:32 AM
Get the right tool for the right job.
Exactly
(http://fjowners.com/gallery/10/1388_09_11_17_12_18_19.jpeg)
So Marty, you, personally, would use this on your brake rotors?
Too answer this question.... Using the soft abrasive fiber discs that Marty posted....I would..... Using a pneumatic 20000 rpm angle grinder. Again, the right tool for the job,
Plus the skill set to use it properlyI am going to weigh in on this, as I believe there are two different tools being talked about. I believe what most are envisioning with the mention of a die grinder is.
An electric die grinder. 7000-10000 rpm with a huge amount of torque. Pictured in photo #1. I will agree with Noel and Pat. To use this tool to grind a few microns off of your rotors is highly ill advised.
On the other hand, I believe what Marty is referring to is a pneumatic die/angle grinder. Pictured in photo #2. These normally spin in the neighborhood of 12000 to 25000 rpm, but with very little torque. Using the blue scotch brite type pads that are available for these grinders and a very light touch, removing the brake pad glaze from a set of rotors is very easily done.
IMO, the tool Pat posted is still the best option.
Fred
FYI, reply 22 is the mention of an Angle Grinder by Bigbore2. Marty was only questioning where we draw the line with offering advise/tools/techniques. With the definition of what an Angle Grinder is, not being the same in everyone's head, the assumptions began. In spite of the confusion, some good options have been presented and are readily available around the world. Grind away...
Quote from: aviationfred on November 12, 2017, 11:19:38 PM
I am going to weigh in on this, as I believe there are two different tools being talked about. I believe what most are envisioning with the mention of a die grinder is.....
Fred
Fred, no one mentioned a die grinder, he said
angle grinder. Many wouldn't know what a die grinder was anyway.
Noel
Quote from: FJmonkey on November 13, 2017, 10:29:00 AM
.... With the definition of what an Angle Grinder is, not being the same in everyone's head....
Mark, shirley you can't be serious. Drill, circular saw, angle grinder. The three most identifiable and owned handyman tools on the planet. This whole notion of hand grinding rotors gets scarier by the minute. :biggrin:
Noel
To take this back a step, I have always been curious as to why folks do this anyway. What is the advantage and do you put your pads on a belt sander so they are matched to your now smooth discs or hit the road with smooth rotors and grooved pads?
Seriously, I've never understood why people do this.
Perhaps someone can explain.
Noel
Quote from: ribbert on November 14, 2017, 06:13:10 AM
Quote from: FJmonkey on November 13, 2017, 10:29:00 AM
.... With the definition of what an Angle Grinder is, not being the same in everyone's head....
2000 Watt 240 Volt 8" Angle Grinder pops straight into my head, :crazy:
Quote from: ribbert on November 14, 2017, 06:13:10 AM
Mark, shirley you can't be serious. Drill, circular saw, angle grinder. The three most identifiable and owned handyman tools on the planet. This whole notion of hand grinding rotors gets scarier by the minute. :biggrin:
Noel
I am quite familiar with angle grinders thank you, and don't call me Shirley... :shok:
Quote from: ribbert on November 14, 2017, 06:26:32 AM
To take this back a step, I have always been curious as to why folks do this anyway.
Seriously, I've never understood why people do this.
Perhaps someone can explain.
Noel
I would have thought this was the most pertinent question on this subject, why folks do it rather than what tool to do it.
Noel
To clean dissimilar pad compounds (transfer layer) off the rotor.
Quote from: Pat Conlon on November 15, 2017, 04:59:58 PM
To clean dissimilar pad compounds (transfer layer) off the rotor.
Pat, I meant those (including yourself IIRC) who do it reguarly, not just when changing pad compounds, however the lack of reponses sort of answers my question.
Noel
Quote from: ribbert on November 16, 2017, 07:58:53 AM
however the lack of reponses sort of answers my question.
Noel
I'd venture to say that it is more the below, than anything else.
(http://fjowners.com/gallery/10/1388_13_11_16_7_09_31.gif)
Quote from: FJ1100mjk on November 16, 2017, 08:17:16 AM
Quote from: ribbert on November 16, 2017, 07:58:53 AM
however the lack of reponses sort of answers my question.
Noel
I'd venture to say that it is more the below, than anything else.
(http://fjowners.com/gallery/10/1388_13_11_16_7_09_31.gif)
Haha, perhaps Marty, but it barely had a heart beat to start with, just one reply.
Noel
I think we should add that alongside the giant *
fuel reserve face palm one. *(humour warning)
Quote from: ribbert on November 16, 2017, 08:33:49 AM
Quote from: FJ1100mjk on November 16, 2017, 08:17:16 AM
(http://fjowners.com/gallery/10/1388_13_11_16_7_09_31.gif)
Haha, perhaps Marty, but it barely had a heart beat to start with, just one reply.
Noel
I think we should add that alongside the giant *fuel reserve face palm one. *(humour warning)
Great idea Noel!
If it comes to fruition, it may be used as much as, if not more than than the Face Palm emoji. :rofl:
Or another potential candidate for submission:
(http://fjowners.com/gallery/10/1388_03_02_17_4_25_31.jpeg)
I used a 3M Roloc yellow bristle disc. I don't think i removed any metal. I had no problem with the new pads although it took more time than the brake hone would have taken.
Chris