Fork upgrade decisions???????

[Thmsdoyle]

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

[FJmonkey]

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.....

[Pat Conlon]

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?

[Dan Filetti]

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

[Thmsdoyle]

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.

[movenon]

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.   Got to go now and check on fleabay.

[giantkiller]

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. 

[keand3]

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

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?

[Pat Conlon]

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

Take a close look at Barry Edward's site, cruise around, lot's of neat things there...

[keand3]

  Should have known that.. 
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.

[candieandy]

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.         
       
             

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.

[keand3]

I might be
Price?

[Pat Conlon]

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)

[keand3]

Okey, the only thing that is stuck in my mind after reading your post Pat:

But, then again, the USD forks gets the chicks (and annoys Mike R)

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!    (hopefully my wife's not reading this.. he he... )

[SlowOldGuy]

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.