FZ1 rear shock into an 89 FJ

[SILVERGOAT]

Hey Guys,
              I am attempting to install an 05 FZ1 shock into my 89 FJ. The FZ1 shock is only about 5/8" longer but both mounts bolt right into the FJ. I cut off the lower battery box bracket and had to notch the upper Mount to accept the reservoir. I just got a set of Soupy's adjustable links to compensate for the longer shock. After I got it all together, it looked great on the side stand(all jacked up), but alas, it sank like a stone when I sat on it. So, all you who have swapped in the FZ1 rear ends, which shock are you using and what weight spring are you using?
               My shock left Monday to go to Racetech with instructions for a 9.8kg spring. If anyone has better info let me know. I am 185lbs plus the extra 115-125lbs of the FJ plus Givi luggage and an occasional two up.

[the fan]

on the 89, the stock rear spring rate is 19.2 kg/mm; 1075 lbs/in.

on that model a 1000lbs/in (17.8kg/mm) to 1100 lbs/in (19.6 kg/mm) is correct for your weight.

Keep in mind that the FJ has not only greater weight, but a completely different leverage rate than the more modern FZ1.

[tqmx1]

and also when you send it to Racetech have them install gold valves in it. The stock valving will not hold up to the extra spring rate the FJ requires

[simi_ed]

Good luck with that!  RaceTech didn't know anything about linkage ratios and required damping or spring rates when I tried to do the GSXR>FJ shock swap.  I finally walked (ran!) away & bought a Penske.

Let us know how it works out, though ...

[racerman_27410]

MAx at traxxion will work with you on getting a custom setup for your shock.

i used a Penske on my FZ1 swingarm.


Kookaloo!


Frank

[tqmx1]

If you want to run a shorter shock the YZF R6R shock is about 1/2" shorter than the FZ1 and has a stiffer spring. They are cheep as heck on Ebay.

[fj1289]

Swapping a different knuckle may also help with the spring rate issue.  An 89-94? FZR1000 linkage should help firm up the spring rate and offer a less progressive ratio like on the newer bikes.  You will have to cut off the centerstand mounting tabs to clear the knuckle where the link arms mount.  FZR600 or YZF600 linkages may also be an alternative - something to experiment with to see how the rate changes. 

[SILVERGOAT]

I am thinking along the same lines. I have a YZF600 swingarm and linkage and I am thinking about acquiring an FZ1 link.  Any help is GREATLY appreciated.