Needing to make the upgrade to the front forks on my 84 FJ! Decisions decisions. What do you guys recommend, keep the stock 84s adding Randy's valves & springs, getting a pair of 89s with blue dots added (would I still need rpm valves)?, fzr forks. Ooooorrrrrrr what other options do I have.
I can be known to ride a little aggressively but also take some trips.
Thanks Tom
Quote from: Thmsdoyle on January 13, 2013, 06:51:48 PM
I went the FZR1000 87/88 front end route, I also went Blue dots and SST lines, HH pads, RPM valves with RPM fork brace and 89 forks...... I am one happy Monkey right now.... But it cost me some $$$, it was worth it.....
Hey Tom, I gotta ask....how much money do you want to spend?
The minimum would be stiffer springs....preferably straight rate springs, not progressive, .90-1.0kg/mm
A good solution: Bypass buying Race Tech cartridge emulators and go straight to RPM valves and springs.
A better solution: Get some RPM valves and '89+ fork lowers so you can run a modern light weight 17" wheel, modern radial tires (wide selection) and the far superior R-1 brake calipers.
A more better solution: Transplant on a USD front end like I have on my '84 from the '91-'93 FZR.
The ultimate itchy bombino set up would be a externally adjustable USD setup from the YZF750 or YZF-R1
How much work do you want to do...and how much do you want to spend?
Has anyone successfully grafted a set of Big Piston Forks (BPF) on an FJ yet? I asked this a while back and got no one chiming in.
I suspect it would take some significant surgery (perhaps too much?) to do so.
Dan
I don't mind spending cash as long as I see results? If I go with 89s and rpm valves and springs, vs say yzf forks what kind of difference could I see. If I would need to postpone till next winter to gather parts & $$ that would be doable. Looking at all options right now & weighing options.
I to am pondering mods to the front end. I am busy with rear end mods (GSXR wheel etc.) at the moment. The front end will have to wait till next fall. But if I were you I would locate a couple of 89+ forks to rebuild using RPM's valves and use his recommend springs. When completed, just change out your forks. Then think about wheels/tires/brakes/rear shock. Oh, then the engine mods, spin on filter adapter, air filters, carbs.... Then you get near polish..... Its a pit of want and desire :)
At present as finances will allow I will try to locate a serviceable 88-87 FZR front rim so I can come up to speed with the rear GSXR mod. Then upgrade my front forks.
I really like the looks of the USD forks (a lot) (lust after) but the cost is a bit to high for me and I think for my kind of riding that I will stick with the RPM valves and springs. It really depends on what you want, your riding style, and how much you want to spend.
I resisted this "Moditus" thing for a while and when it started I find no end to it...... I have spent more money and time on fleabay in the last 4 weeks than I have in the last 4 years. :dash1: Got to go now and check on fleabay.
Quote from: Dan Filetti on January 13, 2013, 07:57:52 PM
Has anyone successfully grafted a set of Big Piston Forks (BPF) on an FJ yet? I asked this a while back and got no one chiming in.
I suspect it would take some significant surgery (perhaps too much?) to do so.
Dan
I was just looking into doing this. I have already done the 2008 gsxr 1000 front on my 86. The biggest thing is extensions you need 2 1/2" The big piston forks tapper in just above the bottom clamp so you can't slide the forks down enough.
Quote from: Pat Conlon on January 13, 2013, 07:17:14 PM
Hey Tom, I gotta ask....how much money do you want to spend?
The minimum would be stiffer springs....preferably straight rate springs, not progressive, .90-1.0kg/mm
A good solution: Bypass buying Race Tech cartridge emulators and go straight to RPM valves and springs.
A better solution: Get some RPM valves and '89+ fork lowers so you can run a modern light weight 17" wheel, modern radial tires (wide selection) and the far superior R-1 brake calipers.
A more better solution: Transplant on a USD front end like I have on my '84 from the '91-'93 FZR.
The ultimate itchy bombino set up would be a externally adjustable USD setup from the YZF750 or YZF-R1
How much work do you want to do...and how much do you want to spend?
Pat, could you please explain what USD is a short for? Diden't understand what it means...
Hehe.. You could do it in norwegian though :good2:
Like the idea of using the FZR or YZF front, but is there more then the tripleclamps you need to change to mount the frontend on the FJ?
Hi Ken, USD means Upside Down, a design which is superior to conventional fork design, just as cartridge internals are superior to damper rod forks.
My FZR1000 USD conversion was relativity painless as the FZR triple clamps and stem fit the FJ's steering neck just fine.
See picts on page 19 of the Bike Gallery.
Marc Rittner did a nice write up on Barry Edward's FJ site, detailing his YZF750 USD fork conversion: http://www.fjmods.co.uk/MarcRittner2.htm (http://www.fjmods.co.uk/MarcRittner2.htm)
Take a close look at Barry Edward's site, cruise around, lot's of neat things there...
:dash2: Should have known that.. :yes:
Steering neck was the word i was looking for in my last post.
I might just start looking for parts to a mod like this. I do think those USD forks do look a bit better:-)
Thanks Pat.
I have a 90 FZR 1000 Front end with a the 17" rim, 320mm rotors, and a good tire for sale. here's what they look like.
(http://fjowners.com/gallery/3/421_06_07_12_3_16_50.jpeg)
The forks need the upgraded 1.0Kg/mm springs and valves from Randy, but they are in good shape. let me know if your interested.
I might be :good2:
Price?
That is a option if you want to stay with a conventional design.
The 1990 FZR1000's used stiffer 43mm stanchion tubes (vs. FJ's 41mm) and a stiffer axle 17mm (vs FJ 15mm) with a wider front rim (3.5") and bigger brake rotors 320mm (vs FJ 298mm)
However, the '90 FZR forks are still damper rod forks, so you need (at the least) Race Tech cartridge emulators.
The YZF600 is another popular option for a conventional design fork upgrade that comes with very nice full compression/rebound cartridge internals, although they use skinny 41mm stanchion tubes.
It is interesting to note that all the modern bikes (still) with conventional forks, in our weight class (500lbs+) use at least 43mm stanchion tubes, FJR, etc,
If you are going to go to all the work of a fork swap, at least get a fork with full cartridge internals. Damper rod forks suck, Race Tech emulators improve the damper rod forks to a point where they are tolerable, however because compression/rebound cartridges can be tuned via external adjustments (or internal shim stacks) they can be dialed in to exactly where you want them, that makes IMHO cartridges superior.
Time to confess....Knowing now what I know, and most importantly based on my riding style and abilities... I would have been just fine with the '89+ FJ lowers, R-1 brakes, wider '87/88 FZR rim, with RPM's valves, springs and fork brace.
But, then again, the USD forks gets the chicks (and annoys Mike R)
Okey, the only thing that is stuck in my mind after reading your post Pat:
Quote from: Pat Conlon on January 14, 2013, 01:17:14 PM
But, then again, the USD forks gets the chicks (and annoys Mike R)
:biggrin:
Well, you do have a good point. As of this moment I am happy with what I've got (89' forks, blue dots, Rims etc.)
As you say, damper rods can be improved, but If I first decide to change the front end (again) it should be with full cartridge internals..
I have to ride the bike this season an se how it feels before decide anything i guess...
And by the way.. I do want the chicks! :good2: (hopefully my wife's not reading this.. he he... )
I've got the best components available in my '89 FJ damper rod forks.
While the ride is MUCH better than stock, they still SUCK compared to the stock cartridge forks on my FZ1. It's not even close.
However, suspension performance is highly variable depending on your frame of reference and what you've ridden to compare against..
DavidR.
I would take $250 for it, but i plan on keeping my Ducati rotors and R1 brakes.
"While the ride is MUCH better than stock, they still SUCK compared to the stock cartridge forks on my FZ1"
That's why some of us have gone to properly sprung FZ1 front forks. Very nice indeed and looks stock.
Eric M
Quote from: SlowOldGuy on January 14, 2013, 04:11:04 PM
I've got the best components available in my '89 FJ damper rod forks.
See this is what I need qualified. Does this include the RPM valves?
Quote from: skymasteres on January 15, 2013, 05:34:49 PM
Quote from: SlowOldGuy on January 14, 2013, 04:11:04 PM
I've got the best components available in my '89 FJ damper rod forks.
See this is what I need qualified. Does this include the RPM valves?
Short answer: Yes.
However, it's all relative. If you're on a time/money budget or your fabrication skills/facilities are limited, then spending $300 on RPM valves and springs gets you one hell of a performance improvement over stock components.
Unfortunately, the FJ fork will never be as good as a true cartridge fork. At least this has been my direct experience. My FZ is more compliant and better damped than either of my FJs. But suspension performance is highly subjective. What one person loves (or is comfortable with) the next rider may consider it trash.
And, it all depends on your budget. A full suspension conversion can be expensive and time consuming. But some people are willing to do it anyway. A spring/valve/fluid change can be accomplished in less than an hour.
DavidR.
Of the know or documented USD conversions which offers the most external adjustability?
2 USDs that I know are the YZF750 and the YZF-R1 have both external rebound and compression adjusters.
Tim (axiom-r) has the R-1 USDs and Frank (Flynt) has the YZF750s
Quote from: Pat Conlon on January 16, 2013, 01:13:02 AM
2 USDs that I know are the YZF750 and the YZF-R1 have both external rebound and compression adjusters.
Tim (axiom-r) has the R-1 USDs and Frank (Flynt) has the YZF750s
Thanks, so I'll assume your FZR1000 forks do not have external rebound and compression adjusters. I know the 91-93 FZR1000 are a candidate and I've seen the write ups on the YZF750s but I haven't seen what year(s) YZF750s make good candidates or the same for the R-1. I've also seen pics of the R-1 mod but no write up on the same. Am I missing that somewhere?
If I recall correctly the YZF750 forks were from the years '97/98.... Frank can you confirm?
What I like about the YZF750 forks (along with external adjustments) is that, unlike the later YZF-R1 forks, the 750 USDs have a mechanical drive where you can still use your oem FJ speedometer.
Correct, my FZR1000 USD forks have no external adjustments for rebound/compression. That is set internally by altering the shim stacks on the Race tech cartridge. Kind of a hassle, I had to r/r my forks a couple of times to get the shims where I wanted it, but once dialed in to my liking, I have left them alone. I do slightly adjust the 1.0kg/mm spring pre-load depending on solo riding vs touring with luggage loads.
Tim, (axiom-r) has a write up here in this forum on his totally bitchen YZF-R1 front and rear end transplant.
Cheers
Quote from: Pat Conlon on January 16, 2013, 04:20:38 PM
Tim, (axiom-r) has a write up here in this forum on his totally bitchen YZF-R1 front and rear end transplant.
Tim did an awsome job on his rear transplant as well. A very modern FJ he has now, FJ porn.
Quote from: FJmonkey on January 16, 2013, 05:11:38 PM
Quote from: Pat Conlon on January 16, 2013, 04:20:38 PM
Tim, (axiom-r) has a write up here in this forum on his totally bitchen YZF-R1 front and rear end transplant.
Tim did an awsome job on his rear transplant as well. A very modern FJ he has now, FJ porn.
This is very true....And to top it off...Tim is a hell of a nice guy...All he needs now is a trip to Oakdale, Ca. for some 1350cc magic from RPM.
I think for over all performance and beauty the top 3 FJs on my tally sheet would be:
Tied for 1st place would be FJs owned by Frank and Frank, both 1350 engines, I like Frank (Flynt) USD forks and I like Frank Moore's custom paint and hard luggage on Brutus.
A close second place would go to Tim's beauty. If/when Tim goes to the 1350cc stump puller, he would move to the top of the tally sheet.
There you have it....the top 3 FJs *in the world*
Thanks again guys. Actually once I found Tim's write up, again, I did remember reading/following that when he was doing it. I just forgot it was an R-1 front end he was grafting on. I was initially tentative about that mod due to the use of the fork extenders. Not a technical reservation by any means just one of those gut feeling things. I'm sure the dam thing is probably stout as all hell and it certainly looks so from the pics.
Quote from: Pat Conlon on January 16, 2013, 05:38:12 PM
...the top 3 FJs *in the world*
I'm blushing Pat. Just wish I could ride the fucking thing! :yahoo:
Frank
Quote from: zero26tb4u on January 16, 2013, 01:52:14 PM
what year(s) YZF750s make good candidates
http://www.fjmods.co.uk/MarcRittner2.htm (http://www.fjmods.co.uk/MarcRittner2.htm) for the run down.
Good question Pat... You want to get the YZF750R forks and the only ones sold in the US. I thought '97 and '98, but that's a guess. YZF750 was '93 -'98.
Frank
Thanks Paddy i happen to think your FJ is a damn fine example as well!
gratuitus Rider, bike, scenery shot in hot rod gentleman's express mode.
(http://i47.photobucket.com/albums/f198/Racerman27410/DAYFIVE062.jpg)
not too shabby for some "beater" bodywork
(http://i47.photobucket.com/albums/f198/Racerman27410/IMG_0856c.jpg)
Looking stock.... I'm glad all this bodywork is safely put away.
(http://i47.photobucket.com/albums/f198/Racerman27410/FrankBike.jpg)
in keeping with the thread i happen to really like the FZ1 forks...looks pretty stock, super easy install and a whole lot of handling/braking improvements in one fell swoop but losing the speedo drive is a deal breaker for a lot of people.... of course if one is modifying then why stop when you can solve a problem AND make everything better...... :good2:
(http://i47.photobucket.com/albums/f198/Racerman27410/IMG_0738.jpg)
KOokaloo!
should be a warning with pics like that,, beware fj porn :biggrin:
I believe Henry, with Hippie Cain's help, modified a set of CBR600 cartridge fork internals to fit inside the FJ forks on his '89. He seemed pretty pleased with the result.
Quote from: Pat Conlon on January 13, 2013, 07:17:14 PM
Hey Tom, I gotta ask....how much money do you want to spend?
The minimum would be stiffer springs....preferably straight rate springs, not progressive, .90-1.0kg/mm
A good solution: Bypass buying Race Tech cartridge emulators and go straight to RPM valves and springs.
A better solution: Get some RPM valves and '89+ fork lowers so you can run a modern light weight 17" wheel, modern radial tires (wide selection) and the far superior R-1 brake calipers.
A more better solution: Transplant on a USD front end like I have on my '84 from the '91-'93 FZR.
The ultimate itchy bombino set up would be a externally adjustable USD setup from the YZF750 or YZF-R1
How much work do you want to do...and how much do you want to spend?
So I'm assuming 89 and up forks will work on my 84? I'm thinking this the route I'll go along with the blue dots and a 17 inch wheel.
Tom
Yep, that's what we are saying....
Good morning,
Re: the fork discussion - No doubt relative to strength, the USD's are stronger and perhaps the larger diameter fork tubes are as well. However, as a practical matter SPECIFIC TO FJ's, it is not likely that they perform better than the stock forks with the Fork Valves from RPM when strengthened with the Fork Brace. Although I have not ridden a motorcycle with USD forks, I have ridden with quite a few late model motorcycles that do have them & in comparison the set up provided by RPM has a performed quite well.
In reading the postings it appears that the replacement forks being recommended are from 1990 through 1998, units from 15 to 23 years old. While no doubt an improvement over stock, I question how technology that dated surpasses a more modern concept.
Remember, the Fork Valves are designed using a different concept than adjustable port size & blow off valves. Inherent in their design is the ability to follow the road surface so well that the front wheel 'pushing' is, if not eliminated entirely, minimized to be almost unnoticeable, regardless of speed or road surface.
Based on my experience over many thousands of miles over a WIDE variety of road conditions the Valves adapt to almost every situation [If you review the Colorado video, the forks are working very well; it was an 1100 mile ride to Colorado and the same settings that worked so well while riding IN Colorado without the added weight of luggage were unchanged from the ride TRAVELING there with luggage]. The same with the ECFR - the suspension settings never changed. I travel from far the northern California mountains to the San Francisco Bay Area periodically where the roads are often not in good repair yet I do not change suspension settings.
Another attribute is that while the Valves do minimize front end dive, they also control very well the "spring back" when the brakes are released, eliminating almost all of the chassis upset that would normally occur.
I wish to emphasize I am not denigrating any fork modification(s); as it pertains to my experience & as it relates to FJ's the Fork Valves are not out performed.
I trust the rear shock in development will offer the same attributes; however how will the surface area of one valve small enough to fit within a shock body perform as well as two front valves with their larger combined circumference? No doubt it will be addressed in fine fashion by the gentleman from R.P. M. I certainly hope the wait is not too long.
Ride safe & keep smiling,
Mike Ramos.
I have to agree with Mike on this. Unless you are using your bike for track days or really wringing the hell outta her on the back roads, the USD upgrade is not going to be much benefit.
However, I do not have the RPM valves in my bike, my forks are not stock by any means. One day, I will take them apart and see exactly what is in there, but this being my 3rd FJ and I know that Progressive springs were installed in the 1st 2, the current forks are far superior. And I really doubt that it's just the brace that's giving them that feel.
I will say that if I had the coin and the inclination, I would upgrade to the USD forks because as Pat said, the USD forks get the chicks... :good2:
CraigO
Heh heh, I knew Mike would chime in.....
I do notice the difference with USDs on roads requiring quick side to side transisions...
Now lets talk maintance....
Did you know that the shim stacks on my cartridges breaks down the fork oil quickly?
Do you really want to *have to* take apart your front end, remove your forks, open up the end caps and turn them upside down to drain them, re-fill 'em, and reassemble everything....Every 7,000 to 10,000 miles?
I use top of the line Golden Spectro synthetic cartridge oil and still the fork oil has the consistency of water when I drain it back out.
The suspension gurus tell me that "shear" is the main cause of my fork oil degradation, which is common to cartridges using shim stacks.
I can really tell the difference in the performance of the front end when the oil needs changing...
I have to think that the RPM valves have to be easier on fork oil...than my Race Tech cartridges.
Even stretching it out to 10, 000 miles, it's still a PIA to have to change the fork oil....
Something to consider..
Quote from: Pat Conlon on January 18, 2013, 11:44:26 AM
Heh heh, I knew Mike would chime in.....
I do notice the difference with USDs on roads requiring quick side to side transisions...
Now lets talk maintance....
Did you know that the shim stacks on my cartridges breaks down the fork oil quickly?
Do you really want to *have to* take apart your front end, remove your forks, open up the end caps and turn them upside down to drain them, re-fill 'em, and reassemble everything....Every 7,000 to 10,000 miles?
I use top of the line Golden Spectro synthetic cartridge oil and still the fork oil has the consistency of water when I drain it back out.
The suspension gurus tell me that "shear" is the main cause of my fork oil degradation, which is common to cartridges using shim stacks.
I can really tell the difference in the performance of the front end when the oil needs changing...
I have to think that the RPM valves have to be easier on fork oil...than my Race Tech cartridges.
Even stretching it out to 10, 000 miles, it's still a PIA to have to change the fork oil....
Something to consider..
Remember Pat, I do not believe you have ridden a bike with my RPM fork valves, so you really have nothing to compare to. Maybe it is time to convert over your 92 so you have something to compare with. Maybe when you come up for the valve adjust, instead of riding one, put both of them in the trailer and we can do the front end on the 92 at the same time.
Okay, lets talk maintenance.
While your USD shim stack forks require the oil to be passed through the shim stack all the time, it is going to breakdown the oil rather quickly. So, you have to change out your fork oil for maintenance at the intervals you mention above. So, you remove the cap & cartridge, drain the oil and refill I presume.
Now, let look at the RPM valves for maintenance.
Mike has now put over 20,000miles on the fork valves and recommended Motul synthetic fork oil since they were installed. He was concerned about the oil and we dropped it at about 7000 miles before he headed off to the 2012 ECR. The oil came out of the forks the same color it went in, with a slight discoloration. The viscosity was visually the same based on a pour test out of a bottle I poured the oil into.
So, we put that oil back in and it has now covered more that 20,000 miles and there is no difference in performance. The next time Mike is over he should have 25,000+ miles on the fork valves & Motul oil and the plan is to drain it to see how it looks.
The Motul oil is not breaking down because the of the bypass technology in the RPM valve that offers superior ride quality coupled with excellent performance. The oil is not forced through a shim stack all of the time, only when required.
So, when we change out the fork oil, the process is the same as your USD forks. No need or
*have to* to disassemble anything from the bike to turn the forks over to drain them.
Remove the caps, pull the springs and use a parts grabber/claw to lift the RPM fork valve and let the fluid run past the valve. Pull the drain plug and let them drain. Refill with clean oil, install the valve & spring put the cap on and you are done.
Easy peasyDepending on the color of the oil on Mike's bike this time, the oil might just go back in. Heck if we can get 50,000 miles out of the oil, we have bypassed the service interval of the USD forks by leaps & bounds.
On another note about shim stack suspension components, since the greatest rear shock option on the planet, the Penske is a shim stack shock, does that mean you need to change the oil in it because it is broken down by having to pass through the shim stack as well. That is not a very good service interval.
If not, can anyone explain why the USD shim stack forks break down the oil faster than the Penske shim stack rear shock?
I will post up tonight regarding the original inquiry on what is the better options based on the actual function of the fork. I have read all of the justifications of the reasons the USD fork is superior to everything else, but after I break it down, there really is only a single benefit, but that benefit is of no use with the latest patented technology. The RPM valves have that technology and there is not a USD fork in the world that does, thus they need the added benefit they offer...
More to come
Randy - RPM
Thanks for the explanation Randy. Good to know about how well your valves treat the fork oil, just as I suspected.
My USDs, by design, have no drain screw, unlike conventional forks, so you got to turn them (or the bike) upside down to drain them.....sigh.....
Alas, no RPM valves in the future for my '92. I have those forks already converted to the Honda F3 cartridges with the special adaptor hats from Jon Cain. Those Race Tech cartridges a just a bit kinder on my fork oil as they only have compression shims. The rebound is valved thru external adjustment via set screw at the cap.
This is what sold me on cartridge forks.....they are a very nice set up. Kudos to Jon Cain.
You've got to remember, this was done (in the dark ages) many, many years before RPM.
Randy, I understand that your valves may be comparable to cartridges, and in some ways superior (fork oil longevity)
However, setting aside for a moment, cartridge vs RPM valve damping characteristics, you can not convince me that a 550lb motorcycle with a conventional fork using 41mm stanchion tubes is structurally equal to the same motorcycle with a USD front end. It Ain't gonna happen.
I have both and I know what I know.
By design the USDs are stronger and suffer less flex. It's just fundamental engineering. The heavier the bike, the more apparent the difference....especially on roads needing quick transitions.
The question that I've come to realize, and I mentioned earlier.....At my age and with my abilities...Am I the kind of rider that can push hard enough to *really* need USDs?
Rest assured, so you guys have the first hand data you need....You and Mike are gonna put some miles on my bike at the next Petaluma WCR.
Cheers..
Quote from: Pat Conlon on January 18, 2013, 01:37:19 PM
Randy, I understand that your valves may be comparable to cartridges, and in some ways superior (fork oil longevity)
However, setting aside for a moment, cartridge vs RPM valve damping characteristics, you can not convince me that a 550lb motorcycle with a conventional fork using 41mm stanchion tubes is structurally equal to the same motorcycle with a USD front end. It Ain't gonna happen.
I have both and I know what I know.
By design the USDs are stronger and suffer less flex. It's just fundamental engineering. The heavier the bike, the more apparent the difference....especially on roads needing quick transitions.
The reason USD forks were introduced was because they eliminate whole boatloads of flex from the front end. It is the ONLY reason they were introduced. Conventional cartridge forks are otherwise equal....
Take two...
Well Pat, I would have responded sooner but I misplaced my wallet which contains my user name. But alas I found it...
Okay, I agree with you that the smaller stanchion tubes are not structurally equal to the USD forks. But as it pertains to the FJ's, that is not the issue. Any benefit of the strengthened USD forks will be minimized by the limitations of the frame itself.
It is the performance/reaction of the forks to the various road surfaces. As experienced first hand while competing against late model motorcycles with USD forks, the Fork Valves leave nothing to be desired and are on par with any of the latest offerings. There is a posting from the Cherohola that shows how the FJ was overpowered by the late model motorcycles, however once the turns were entered, the old FJ with the skinny stanchion tubes and skinny axle axle performed very well, and well beyond all expectations.
Concerning the fork oil issue which has been recently discussed: prior to installing the Fork valves I would normally change the fork oil when I cleaned the air filters. However, when I voiced my reservations to Randy, he drained the fork oil and sure enough it was like new.
I do thank you for the opportunity to ride your motorcycle at the West Coast Rally. However I must respectfully decline - just as with drinking & smoking, my parents suggest that I do not date the chicks before I turn twenty one. They fear that I may be corrupted by undue influences.
Respectfully,
Mike Ramos.
Quote from: racerrad8 on January 18, 2013, 01:06:24 PM
More to come
Randy - RPM
I like the sound of that... could I have the stiffer forks (to go with the stiffer '92 frame)
and the superior valving technology? I hate
or!
Frank
Quote from: Flynt on January 18, 2013, 10:25:46 PM
I like the sound of that... could I have the stiffer forks (to go with the stiffer '92 frame) and the superior valving technology? I hate or!
Frank
Nope, you are stuck with
OR for now. The cartridge technology has not been broached by the manufacture. USD forks have dual pistons and they have not established a way to incorporate the IAT bypass into the valve(s) and they tell me they do not have enough time to venture that way as they cannot keep up with the demand for the products they manufacture now.
On another note, I am going to be testing forks tubes, 41 & 43mm for flex. I have already gotten the specs on the FJ 41mm fork tubes and have plenty on hand, and I have a call into a couple of places to obtain a 43mm fork tube for testing the flex.
Once I get the 43mm tube in hand I will do the testing and we can have solid numbers to compare the two for flex.
I can tell you, that since the RPM fork valve has come onto the market and they use a much softer spring than the old school design products which has significantly reduced the flex of the FJ forks as well. If there is not a big, stiff spring controlling the travel, the tube is able to travel more freely and there is not as much induced flex due to spring resistance.
Randy - RPM
Wow Pat and Mark- thanks for the props on my FJ! I have to agree your bike holds a slot on that list and it is only a matter of taste on which one it might be... we should all be proud and happy to bring these FJ's up to "awesome".
I will say that one of the benefits I enjoy with the USD front is the way the fork sliders are stashed away behind the fender- I do long miles on my bike and I flog it in the turns too (albeit not quite as hard as some of our own here) when the bike had OEM forks on it they got ruined twice just by touring. The sliders got badly pitted from rock impacts and I could not keep seals in them - even after careful de-burring. I replaced them and it happened again.... I even used those plastic guards- to no avail. I was envious of the newer bikes that had that problem eliminated with the USD design. I won't even bring up the 6 piston calipers and huge floating discs which was by far the most dramatic difference with the conversion. It took the longest adjustment period as well - the brakes are freaking amazing compared to stock.
About the mechanical drive for the speedo- I think you could chose to use any USD fork set from a modern bike and then use the most modern front wheel that still has the mech drive (can't recall the YZF750 wheel I think) and make spacers to align it.
For me the simplicity of keeping the entire front end together from the 07 R1 was more important and when (see, now I say "when" instead of "if") I launch into the next set of mods (*****1350*****) I will also endeavor to add a Cable X Box to get my speedo working.....
I have been reading and rereading the threads from both the 1350 builds - Thanks Franks & Randy too!! - for blazing a trail to follow! :good:
Cheers to all!
PS - Monkey! Glad to hear about your front end work !!
Ok, starting my search for 89 or newer forks for my 84 upgrade. If anyone comes accross a set let me know.
Quote from: Thmsdoyle on January 21, 2013, 01:48:28 PM
Ok, starting my search for 89 or newer forks for my 84 upgrade. If anyone comes accross a set let me know.
A big thank you for all the fork talk, has helped with my decision.
Thms
Damn it!!!!!!!!!!!! I think I'm getting sick. Just when I thought I was for sure going with the 89 fork mod. Now I've found a complete 2001 yzf r1 front end. What to do what to do??? Moditis sucks. As I type this I can feel my wallet getting thinner. :hang1:
Quote from: Thmsdoyle on January 22, 2013, 03:42:31 PM
Damn it!!!!!!!!!!!! I think I'm getting sick. Just when I thought I was for sure going with the 89 fork mod. Now I've found a complete 2001 yzf r1 front end. What to do what to do??? Moditis sucks. As I type this I can feel my wallet getting thinner. :hang1:
Well, depends on how straight forward you want things to be. I've done a few early R1 fork conversions, but they are more work - and require you to gather a lot more parts to do the job well -- but it is possible to keep the gear driven speedo if you adapt a YZF1000 ThunderAce wheel. I'll follow with more details if you are interested.
And I don't consider moditis a disease...more that its just the natural order of things!!
Quote from: Thmsdoyle on January 22, 2013, 03:42:31 PM
Damn it!!!!!!!!!!!! I think I'm getting sick. Just when I thought I was for sure going with the 89 fork mod. Now I've found a complete 2001 yzf r1 front end. What to do what to do??? Moditis sucks. As I type this I can feel my wallet getting thinner. :hang1:
My wallet is thinner too, but I smile more often. :biggrin:
Quote from: FJmonkey on January 22, 2013, 05:55:51 PM
Quote from: Thmsdoyle on January 22, 2013, 03:42:31 PM
Damn it!!!!!!!!!!!! I think I'm getting sick. Just when I thought I was for sure going with the 89 fork mod. Now I've found a complete 2001 yzf r1 front end. What to do what to do??? Moditis sucks. As I type this I can feel my wallet getting thinner. :hang1:
My wallet is thinner too, but I smile more often. :biggrin:
I have no wallet left! :good2:
Quote from: keand3 on January 23, 2013, 05:20:17 AM
Quote from: FJmonkey on January 22, 2013, 05:55:51 PM
Quote from: Thmsdoyle on January 22, 2013, 03:42:31 PM
Damn it!!!!!!!!!!!! I think I'm getting sick. Just when I thought I was for sure going with the 89 fork mod. Now I've found a complete 2001 yzf r1 front end. What to do what to do??? Moditis sucks. As I type this I can feel my wallet getting thinner. :hang1:
My wallet is thinner too, but I smile more often. :biggrin:
I have no wallet left! :good2:
:drinks:
I recall this post from David and wanted to make sure it was present in the actual conversation about the RPM fork valves.
Randy - RPM
Quote from: SlowOldGuy on January 23, 2013, 09:55:24 PM
Just a clarification to a previous post I made regarding RPM fork valves.
I installed the valves on my '85 FJ a few months ago and was initially struggling to get the anticipated performance out of them. Randy was great, of course, working with me to get things straightened out.
My main complaint was what felt like a pogoing front end. I changed from the 5wt fork oil to 10wt and the response seemed to be better. The weather has been really cold here for the last few weeks, so I haven't been able to do any additional tuning.
Last Saturday, the weather finally broke so I took the '85 out to lunch. The suspension was absolutely terrible, worse than I remember it being. At a stop light I decided to check the sag so I pulled up on the rear end to gauge the sag. The rear end didn't budge so I bounced down on the seat. Again, NO movement at all from the rear end! Evidently my high $$$ Penske had locked up solid for some unknown reason (probably mostly due to non use).
I limped home, pulled the shock off, and sure enough it was locked up solid. I removed the spring and a few blows with a rubber hammer managed to free up the plunger. I was not impressed.
Sunday was another good day so I took the FJ on an extended ride. Needless to say, the suspension action from both ends was much better. I have no idea when the Penske froze up or whether it was a gradual thing or did it while sitting for the last few weeks.
I still have some more adjusting to do to the RPM valves (mostly to get back to Randy's recommended settings), but my statement that the RPM valves were not even close to the performance of my FZ1 suspension was not exactly accurate. With a proper working rear shock, I feel the RPM valves are now far closer to the FZ1 cartridge performance than I previously experienced.
My apologies to Randy for casting doubt on his product. For anyone considering the RPM valves, I would highly recommend them for a huge performance boost over the stock components.
DavidR.
Clarification on a Comment I Posted on RPM Fork Valves (http://www.fjowners.com/index.php?topic=8291.msg76440#msg76440)
I found it once and can't seem to find it again about if the 85 1100 trees the same as the 1200 trees ? Reason I ask is I've update the rear with a R6 wheel and am planning on going with a USD front from a yzf1000 and from what I have read most are done on 1200s . My. Question is can I use the 1100 stem in the YzF yoke following ritters set up instead of the 1200s ? Either way its getting done just trying to save money where I can :mail1:
Quote from: DreadRock on November 27, 2013, 09:54:31 AM
can I use the 1100 stem in the YzF yoke following ritters set up instead of the 1200s ?
Yes, stem is same.
Frank
Quote from: DreadRock on November 27, 2013, 09:54:31 AM
can I use the 1100 stem in the YzF yoke following ritters set up instead of the 1200s ?
BTW - Marc used yzf750 forks, not the 1000 version. I think all of the USD YZF1000 forks are shorter and require an extension to give you the right length for the front of the FJ.
Marc also spent $$ with GP Suspension getting the valving tuned for the FJ and for him. I did the same when I rebuilt them...
Also, the stock yzf750 tubes feature crappy chrome work that wears through in a distressing display of scratching and overheated/purple-blue appearance (this may be true for all early KYB USD tubes). Getting that fixed was also several hundred $$ in new Racetech tubes and fork rebuild.
I think they are a wonderful upgrade... very tunable and supple, improved stiffness, just great looking, etc. However I would not say they are cheap at all.
Frank
Good info thanks guys !
I've got all winter to get it done ! And that's a very good point between the 750 and 1000 lengths ! Think any good upgrade costs at some point or other and if your going to go for it then go for it !
Again thanks will get a write up on the rear wheel and fork set up when I'm done as I see alot of guys asking about the 1100s but seems to be way more info on the 1200s !
Pat has yzf1000 USD on his '84 I believe... maybe he can share some details with you.
Frank
Negative, I used the '92 FZR1000 front end. Plug and play.
On the back I used the 1997 YZF1000 (aka:ThunderAce) swing arm and wheel assembly (just like yours)
I used 2008 gsxr front end on mine the gsxr1000 front end is a little over sprung. (Stift) from the factory. So I thought on a heavier fj they would work. Actually had to back off the settings a little. Have a little weld added to the bottom of the fj stem and have it machined down to fit the gixxer triple botom and a collar to fill in the space on the top triple. I've got 3 1/3" extensions made. They give me about an inch of adjustment on handle bar hieght. I used the gixxer clippons flipped them over. Cut off the bars made risers to match the fj bars exactly. Made the risers with a jigsaw and belt sander in my garage. I used a trailtech vapor for speedo and tachometer also has shift lights maintenance reminder engine oil temp and a bunch of other stuff.for $117 off ebay. Used the stock idiot lights. And a round digital fuel gauge in stock location and digital voltmeter on the other side. I weighed the complete gixxer front, wheel fender everything. Against the stock fj components. The gixxer front was only 9.8lbs lighter than the fj's I thought it would be more. Oh yah the digital gauge set up is alot lighter too so even more weight savings.
Quote from: Flynt on November 27, 2013, 10:10:52 AM
Quote from: DreadRock on November 27, 2013, 09:54:31 AM
can I use the 1100 stem in the YzF yoke following ritters set up instead of the 1200s ?
BTW - Marc used yzf750 forks, not the 1000 version. I think all of the USD YZF1000 forks are shorter and require an extension to give you the right length for the front of the FJ.
Marc also spent $$ with GP Suspension getting the valving tuned for the FJ and for him. I did the same when I rebuilt them...
Also, the stock yzf750 tubes feature crappy chrome work that wears through in a distressing display of scratching and overheated/purple-blue appearance (this may be true for all early KYB USD tubes). Getting that fixed was also several hundred $$ in new Racetech tubes and fork rebuild.
I think they are a wonderful upgrade... very tunable and supple, improved stiffness, just great looking, etc. However I would not say they are cheap at all.
Frank
Frank, is any of the improved stiffness from a fork brace, or is it purely a function of the forks themselves?
Ed, Frank was describing his YZF750 USD forks....no fork brace on USD's.... Don't need no stinkin fork brace... :sarcastic:
Quote from: simi_ed on November 27, 2013, 02:37:17 PM
is any of the improved stiffness from a fork brace...
USD... no brace....
Frank
Quote from: Pat Conlon on November 27, 2013, 11:19:55 AM
'92 FZR1000 front end.
that's right... another option.
Frank
Having been down the USD path...without a doubt I would go with 89+ forks, new bushings, RPM valves, springs and new Yamaha seals. Add blue or gold dots and maybe an 87/88 FZR 17x3.0 rim. I think with the new RPM inertial style valves, no need to go USD. Hell, I wasn't planning to do USD forks when I did, just at the time they were a lot less expensive than the YZF600. Conversion I planned to do. Now, I'd just do the RPM valves and springs.