Track Day Winner
Join Date: Jun 2001
Location: Madrid, Spain
Motorcycle: GSXR 750 K5 Anniversary
Have I screwed up my forks?
A few weeks back I took the front end off the bike to put new steering bearings and fork seals in. Bike is s 750 K5.
Long story short, but the bike was handling like a pig on a stick. In fast bends I was getting the front end bouncing and weaving all over the place.
Once I had made sure that the steering bearings were correctly adjusted (they were a bit tight I admit), I turned to the suspension. As a first step I put all the settings, front and rear back to factory, comp. rebound and springs, but if anything it made it worse (I am "Moto 3" size, so usually have to soften everything when I get a new bike).
So I read through the Suspension 101 thread (great info there) and set about checking everything and very quickly discovered that I had no / very little front end rebound damping. Compressing the forks by grabbing the brake and pushing down hard would result in the forks springing back up till they topped out and then dropping down again.
The issue seems to be something to do with the rebound adjustment on the forks. The manual says to wind the adjusters all the way in, then back them out to the factory setting, but when I do this, they don't wind in and stop at a noticeable stopping point as I would expect, they just get harder to turn as the adjuster is wound in, I ended up having to use a fair amount of force on the screwdriver to get them to what seemed to be the fully wound in position.
Then, on winding them back out, the adjusters are stiff to turn to a point, then seem to free up completely and turn very easily, without any resistance.
At the factory setting (1.5 turns out) the adjusters are very free and seem to give very very little rebound damping. I wound them in to where they start getting stiffer to turn (0.75 turns) and I have now got sufficient rebound damping to make the bike OK to ride at a moderately fast pace, but I am concerned.
I re-read the manual and it states that before removing the fork caps, you should adjust the rebound adjuster to the softest position, then on re-assembly there is a measurement to be taken of the rebound adjuster before putting the fork cap / rebound adjuster back together. But I did not do any of this... I just unscrewed the cap, leaving the rebound damping adjuster as it was and then reassembled everything after changing the seals.
Have I screwed it up? It is not entirely clear to me how the long needle of the rebound adjuster interacts with the damper, so I am having trouble visualising what may have happened in there...
Anyone any clues?