CrashTestDanny
Registered
Well, I probably wouldn't bother to even post this since I'm riding an ST, but I've talked with more than a few of y'all about my suspension and cupping problems and want to see what you think of my theory.
I've got 20k miles on my ST and have replaced 4 rear tires with moderate to severe cupping and more than 50% of the tread left. Until now, I have been able to see cupping on the tires as early as 1k miles. The last tire was the worst - in 2500 miles it was shot and even though I could have repaired the screw hole in it, I decided not to because of the cupping.
The rear suspension on the ST has two adjusters; spring preload and a "mystery meat adjuster" which is documented to have "Hard" and "Soft" adjustments. I'm pretty sure that the screw controls damping for either compression damping or both compression and rebound damping. I had adjusted this screw halfway from the stock setting to the full "Hard" setting when I put the last tire on, thinking this would help the bike handle the twisties better. When I saw how bad the last tire was in such a short distance, I immediately blamed that adjustment, so I set it to halfway from the stock position to the "Soft" position. As of yesterday, I have about 1300 miles on the new Avon Storm (same as the last tire) and can not see or feel any signs of cupping. Therefore, I believe that the suspension adjustment has corrected the problem.
Ok, so here's my theory - y'all who know about this stuff, please give me your thoughts: I think that when compression damping is too great, the rear shock and spring no longer absorb the dynamic loads caused by the road and that forces the tire to flex to absorb those loads. This flexing, according to my theory, causes cupping? Sound reasonable?
I've got 20k miles on my ST and have replaced 4 rear tires with moderate to severe cupping and more than 50% of the tread left. Until now, I have been able to see cupping on the tires as early as 1k miles. The last tire was the worst - in 2500 miles it was shot and even though I could have repaired the screw hole in it, I decided not to because of the cupping.
The rear suspension on the ST has two adjusters; spring preload and a "mystery meat adjuster" which is documented to have "Hard" and "Soft" adjustments. I'm pretty sure that the screw controls damping for either compression damping or both compression and rebound damping. I had adjusted this screw halfway from the stock setting to the full "Hard" setting when I put the last tire on, thinking this would help the bike handle the twisties better. When I saw how bad the last tire was in such a short distance, I immediately blamed that adjustment, so I set it to halfway from the stock position to the "Soft" position. As of yesterday, I have about 1300 miles on the new Avon Storm (same as the last tire) and can not see or feel any signs of cupping. Therefore, I believe that the suspension adjustment has corrected the problem.
Ok, so here's my theory - y'all who know about this stuff, please give me your thoughts: I think that when compression damping is too great, the rear shock and spring no longer absorb the dynamic loads caused by the road and that forces the tire to flex to absorb those loads. This flexing, according to my theory, causes cupping? Sound reasonable?
