USD forks on my 1990

[Mike 86 in San Dimas]

that number seems realistic. Assuming you are doing most labor yourself and or slaving some buds. Add some polishing, caliper and fork rebuild and so on, on that used stuff  you buy and it adds up. I'm taking it slow just to spread the spending out over several months. Once all the stuff is accumulated and ready to bolt up, I'll try to hijack Pat and Mark for a week end...or two.

[Pat Conlon]

If Tina's making lunch....I'm there!  Major yum!

[woodcreekpete]

If Tina's making lunch....I'm there!  Major yum!

Here's a question for ya Pat. I'm swapping a 91 Fzr 1000 front end onto the FJ. What wisdom can you impart as far as springs are concerned? I'm assuming the stock FZR springs are a bit weak for the extra weight of the FJ. Any preferred brand? Also, were there any mods needed to the fork stops? Any other tidbits of experience would be much appreciated. Thanks, Peter

[Pat Conlon]

Hello Peter,  The '91/92 FZR1000 USD conversion is the easiest to do....no screwing around with steering stems and the mechanical drive on the FZR wheel plugs right in to your FJ's speedo cable. I followed the info on Barry Edward's site: http://www.fjmods.co.uk/usdforks.htm

You are correct, I found the stock FZR springs are a bit light for the FJ. They are .77 kg/mm and I wanted ~.95 kg/mm. I got the Race tech fork springs (see link below) The stock FZR cartridge fork valve can work with the .95 springs, but remember.....
The FZR is Yamaha's de-tuned version of the YZF product line (read: less expensive) Here is the downside of the FZR1000 USD forks....unlike the YZF (or GSXR) forks, there is no provision for external adjustment of compression or rebound. All you have on the FZR forks is a provision for spring preload, so....

I went ahead and bought some Race Tech cartridges and set the compression and rebound via shim stacks on the Race Tech cartridge.
http://www.racetech.com/ProductSearch/12/Yamaha/FZR1000/1991

Once I got the shim stacks where I wanted, I found no need for further adjustment, so external adjustment was not really needed after all..

Steering stop mod was straight forward (you will see) as was the grinding on the FZR top triple for the ignition key barrel fitting. The trick was figuring out how to mount the FZ-1 handle bar. I pressed in steel sleeved rubber bushings on the top FZR triple for the thru bolt on the bar clamps and used back up plates on the underside of the top triple for secure bolting of the bar clamps. I've tried other handle bars, but I keep coming back to the  7/8" FZ-1 bar that has threaded ends for my Vibranator bar end weights (or stock FJ bar ends if you wish)

Cheers   Pat

[woodcreekpete]

Hello Peter,  The '91/92 FZR1000 USD conversion is the easiest to do....no screwing around with steering stems and the mechanical drive on the FZR wheel plugs right in to your FJ's speedo cable. I followed the info on Barry Edward's site: http://www.fjmods.co.uk/usdforks.htm

You are correct, I found the stock FZR springs are a bit light for the FJ. They are .77 kg/mm and I wanted ~.95 kg/mm. I got the Race tech fork springs (see link below) The stock FZR cartridge fork valve can work with the .95 springs, but remember.....
The FZR is Yamaha's de-tuned version of the YZF product line (read: less expensive) Here is the downside of the FZR1000 USD forks....unlike the YZF (or GSXR) forks, there is no provision for external adjustment of compression or rebound. All you have on the FZR forks is a provision for spring preload, so....

I went ahead and bought some Race Tech cartridges and set the compression and rebound via shim stacks on the Race Tech cartridge.
http://www.racetech.com/ProductSearch/12/Yamaha/FZR1000/1991

Once I got the shim stacks where I wanted, I found no need for further adjustment, so external adjustment was not really needed after all..

Steering stop mod was straight forward (you will see) as was the grinding on the FZR top triple for the ignition key barrel fitting. The trick was figuring out how to mount the FZ-1 handle bar. I pressed in steel sleeved rubber bushings on the top FZR triple for the thru bolt on the bar clamps and used back up plates on the underside of the top triple for secure bolting of the bar clamps. I've tried other handle bars, but I keep coming back to the  7/8" FZ-1 bar that has threaded ends for my Vibranator bar end weights (or stock FJ bar ends if you wish)

Cheers   Pat

One look at the top triple and it looks like it was designed for rubber mount risers. I want to try to keep the FJ clip-ons though. A quick measurement makes it look possible to weld a 43mm piece of 1/8" wall tubing to the tube cap to mount the clip-on and still be able to adjust the preload and tighten the caps. All depends on having enough meat for a good weld. Haven't got it home yet to do a more accurate assessment.

[Pat Conlon]

Please be careful.
The thought of a weld failure while leaned over in a 80 mph sweeper, gives me the heebee geebies.

[oldktmdude]

   My opinion of the best method to retain your original clip on bars is to fabricate an adaptor plate to bolt to the top triple clamp plate.
Fairly simple to make if you have the tools to do so. I used 6mm plate steel and some stock tube to mount the bars.
I made some caps out of aluminium to cover the holes in the end of the tubes. . (not fitted in the pic below)
Like Pat, I don't recommend welding tubes to the fork caps.
   Regards, Pete.

                   

[woodcreekpete]

   My opinion of the best method to retain your original clip on bars is to fabricate an adaptor plate to bolt to the top triple clamp plate.
Fairly simple to make if you have the tools to do so. I used 6mm plate steel and some stock tube to mount the bars.
I made some caps out of aluminium to cover the holes in the end of the tubes. . (not fitted in the pic below)
Like Pat, I don't recommend welding tubes to the fork caps.
   Regards, Pete.

                   

Yea, I think I'm gonna have to throw in the towel on this idea. I figured a wall thickness of .125 would have been enough meat for a serious weld but figuring an inner diameter of around 1.6", my stubs wouldn't be much thicker than heavy gauge tin foil. Looks like it's back to the drawing board. Thanks for the input guys!

[fj1289]

My first thought is to machine new fork caps with mounts for the FJ bars.  But not sure I'd want to always be trying to loosen the right fork cap every time I counter steer into a right hand turn...

[giantkiller]

My latest design for fork extensions. For the Gixxer forks was welding them to the top nut on the forks. Done by a professional extremely good welder and then machined down by a professional machinist. Both. Racers themselves. One is now factory sponsored snow cross racer. Use to be super bike racer. So they know about the stress it's under.

[giantkiller]

They're clamped by the upper tripple clamp no spinning them off.
Oh and I made bars to mach the fj. With the clamps from the Gixxer clippons. Some 7/8 round aluminum bar. And aluminum rectangular bar.

[giantkiller]

I made the bars with a Craftsman jigsaw and hf belt sander.

[woodcreekpete]

I made the bars with a Craftsman jigsaw and hf belt sander.

Next great thought - bear with me here, I just woke up
1. Remove the adjuster from the cap and machine the head of it round. And as small as possible
2. Weld a large  (14mm?) aluminum allen head to it to take over the adjusting function
3. This will give back the thickness of the stub and then some. I was losing thickness due to the extra space needed to get a socket in there
4. Machine the stub with a serious bevel for welding
5.Hire somone other than me to lay down some high strength beads

Anybody got a spare set of caps just in case?

[fj1289]

They're clamped by the upper tripple clamp no spinning them off.
Oh and I made bars to mach the fj. With the clamps from the Gixxer clippons. Some 7/8 round aluminum bar. And aluminum rectangular bar.

That is the essential difference with this design - the extension is gripped by the top clamp. I'd have no worries at all with these.