Honda Motorcycles - FireBlades.org banner

92 blade front fork suspension oil?

5K views 10 replies 4 participants last post by  Soulie89 
#1 ·
I m doing the oil seals on my bike and i was wondering what is the best oil to use in the forks as i drive on rough roads half the time other than what the manual specifies of course.
 
#4 ·
October 1993 issue of SportRider magazine has a "home fix" for the twitchyness the magazine guys complained about. I see the old issue for sale on ebay. They recommend 7 weight, cut a few coils from the springs, make up preload spacers and drop the forks through the clamps til the cap is flush, etc. If your interested I'll go get the old magazine from my garage and pm you every word from the article.
 
#6 ·
Ok, here we go, this is from SportRider Oct 93 article by Eric Putter after talking to Jim Lindemann of Lindemann Engineering and Jeff Favorite of Fox Factory suspension. "Hondas cbr900rr has the most confused front end of any sport bike." Favorite believes the 900 comes undersprung, overdamped and underpreloaded, with tons of friction from its massive 45mm tubes and large cartridges. Triple clamps with too much offset and too little trail and the equally confused choice of a 16 inch front wheel. "The abundance of low speed damping makes the front end skip around on the most minor of bumps. The lack of high speed damping allows the front end to bob up and down on abrupt transitions Finally the soft initial spring rate allows the fork to dive too quickly through the travel into the stiffer final rate, which retaliates by rebounding too fast. Cranking up the preload only exacerbates this problem, especially under power."
 
#7 ·
" The Home Fix" For starters, both Lindemann and Favorite suggest you purchase a high quality steering damper. If there was ever a stock motorcycle that needed one, its the big cbr 900rr. A good damper would hide some of the 900's nervous behavior, combined with the following.....( I going to skip the dismantle procedure) Jeff Favorite suggests cutting 2 coils off the tightly wound end of each spring to increase its rate. Fluid, Jim Lindemann recommends Showa SS-7m (get at Dealership) while Favorite swears by 7w Maxima Racing cartridge fluid. Lindemann suggest filling the bottomed out fork by literally pumping fluid into it until its 115mm from the top of the fork.
 
#8 ·
To get the proper amount of preload, make up sets of spacers from PVC tubing (probably schedule 40 pvc because it has thicker wall thicknees but the article doesnt specify) the same diameter as the springs. They should be 2.75 to 3 inches tall depending upon your weight. Install the springs and spacers then button the fork back up. Another trick Lindemann let us in on is to pull the fork down in the triple clamps until it is flush with the edge of the fork cap, but no further. This will increase the rake and remove some of the twitchiness. Once you reassemble the fork and have it fixed in the proper position within the clamps, set the sag for 1.25 inches.
 
#9 ·
Jeff Favorite maintains this quick fix will speed up the damping overall and make the bike ride better-----the available travel will be more towards the middle of the range (whereas the stocker rides too low in the travel) where it can be used effectively heavier spring will also help cure the twitchiness and smooth out bump absorption.
 
#10 ·
Theres also the "ship it out for a professional fix, but that suggest new triple clamps and revalve, but the home fix should make a noticeable difference. And finally Jeff Favorite says " Any fine tuning of your 900's fork will produce immediate results that will help produce the world beating motorcycle the CBR900RR was destined to be in the first place."
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top