Join Date: Dec 2009
Location: central mississippi 39180
are you talking about the rattle on decelleration and when holding a constant RPM after accelerating?
its usually the rollers rattling around in the roller valleys. when you get a set of 8 rollers, nine times out of ten at least one or two in the bunch is going to be a different weight. i've seen MANY clutch setups that have had weights that were 1-2 grams out of specs from the others. what happens is this:
when your rollers roll out to the ends of the roller valleys from centrifugal force, the RPMs of the engine turning the movable sheave pull the rollers outward against the fixed plate and in turn pushing the movable sheave inward, if you have 7 rollers that are 20grams, all 7 of those rollers are going to be pushing against the fixed plate with the same amount of force, but if you have 1 that is a 19 gram roller, that one lonely 19 gram roller is not going to be pushing against the fixed plate with the same amount of force. usually this causes the lighter rollers to actually fall out of contact with the fixed plate on decelleration. a lighter roller will try to roll back down in its roller valley before the other heavier weights roll back downward. so what happens is you get the lighter roller halfway down in the roller valley all by itself, not pushing against the fixed plate at all since the centrifugal force is not great enough to hold it against the fixed plate, and the roller that is just sitting in the roller valley with no resistance on it rattles horribly against the walls of the roller valleys. that is the main reason the yamahas use grease in their roller valleys to keep the noise down from roller rattle. if you have a gram scale, and i mean a GOOD gram scale, you can weight match therollers and they'll stop doingthat. when you get all the rollers to the exact same weight, they'll all push against the fixed plate with the same force, and you wont ever have one hanging out by himself in the roller valley not doing his job.