Why do front tires cup? So we are all talking about the same thing, cupping is a hi lo wear pattern. Right?
How does this happen? The tire must be bouncing to some degree, or not evenly weighted. Each different tire has a different springs constant, or natural frequency comprised of construction and air pressure. Most people are using stock yamaha springs and shocks, my guess? Certain tires, from the archives tend to cup more than others. I suggest that these problem tires, inflated properly have a natural frequency that isn't properly dampened by the suspension components, front and rear. Other factors are compatible rear tire frequency, as a fore and aft pitching motion will overload the smaller tire, and start the evil wear, once started, which will exacerbate the quickly. Tire size is also in there. Road conditions can also create a problem, and the ABS could be at fault also. What is the frequency of the cups, does it match the ABS frequency? Lost damping, worn pivot points, worn shock mounts all will contribute to the problem. Find tire combos that have been tested, lots of info in the archive. Make sure suspension is in proper order, see that pressures are kept up. For the stock shock folks , check with lindeman or any good shock rebuilder. Most stock shocks that are gas pressurized at the factory, can be rebuilt by adding a valve to the body after disassembly. The rebuild won't be free, if it can be done, but it will be less expensive than good aftermarket units. Just thought I'd put it down in one msg, and I'm sure there will be comments. Does one of the GTS websites have a tire page? Seem like the collection of facts should be somewhere. I don't why I'm still standing up here, I best get down :^) silhouette on the target.... Jerry Wills
