am finding the front end on my 1991 vfr a bit on the soft side and thinking of putting a slightly heavier grade of oil in the forks or fitting graduated springs. anyone tried either? also, the opportunities to use top speed around here are very limited and was thinking of fitting smaller front sprocket.Whats the best size and does it make much difference and how much do you actually lose on top speed?
I am not sure how to advise on the forks. They can be adjusted at the top. On top of the forks you will see a slot for a screwdriver and the opst that slot is on has circular marks on it. Those are for adjusting the frimness or softness of the forks. I think the third mark from the top is the standard setting, and turning clockwise increases firmness and counter-clockwise makes it softer. On the sprocket, most posts I have read the riders have gone to a 15 tooth front sprocket. Check witht the local dealer about the possibility of having to shorten the chain by removing one or more links. Vinny
The 91 didn't have adjustable preload on the front forks like the 93, so you have to change oil and or springs and or both to make an improvement. I found that fresh oil of the factory spec worked fine for about two seasons and then flush and fill again. I don't know what is available on the aftermarket to improve these forks but you could upgrade to the units off of a 93 model as I believe that they are also cartridge style internals in them as well as having preload adjustability.
I was talking to a bike suspension guru the other day as I'm looking to replace the existing rear spring with a higher rate. He strongly advised to check and make sure that the front springs were not going to be out of balance with the new rear. Its all about setting up the sag of both the rear and front - in that order - something which until recently I had no real idea about. A quick search on the Net gave me plenty of info - change the spring rate and your also looking at revalving the dampening. Following thru with the process for setting up sag on both the front and rear had two results - yes I do need to up my spring rates but even with the existing springs I got a better set up for sharper handling than I did before. Check out Robert Kehl's article for suspension setup - good value!
Er well, kinda.. Not really Vman, turning the preload in or out does NOT make the forks stiffer or softer, all it does is extend or shorten the "starting point" of the height of the fork. Consider this : the fork spring is compressed between two points inside the fork, at the top is the preload adjuster. When you wind this into the fork you are making the fork leg (as a whole) extend relative to the weight acting on the fork at that point, since the fork is not fully extended in the at rest position. It takes no greater force to move the fork another 2" in compression than it does to move it the initial 2". (Disregarding the harder sprung section of spring used to prevent bottoming or topping out of the forks). Most springs are linear ie the same force is required to compress the coils throughout the length of the spring, but progressive springs are also available which do get stiffer as they become compressed. Turning in the preload adjuster on a fork with progressive springs will still not make the fork stiffer - merely extend the fork further toward the top of it's travel. Rod
Hello....the previous fella that owned my '91 put racetech (spelling?) in the front end of my VFR and it works quite well!!
