PIRELLI TIRE WEAR QUESTION

Hi Dave,

I am learning more about suspension and reading tires, and purchasedyour videos from onthethrottle - they're great! I also have seen yourtire web page http://www.feelthetrack.com/tire-wear.html. But I stillhave a question that I was hoping you could clear up. I am a ControlRider with NESBA and would consider myself of decently proficient rider.I happen to be using a Pirelli Diablo Corsa III tire this past weekend(as it is our sponsored Control Rider tire), and it showed somethinginteresting that I would not have caught on a DOT race tire like theSupercorsa. I saw what looks exactly like the rebound cupping. Butsince the DCIII has tread that goes all the way to the edge of the tire,I saw that from the very edge of the tire to about an inch in, the tirehas the trailing edge raised. But then from about an inch off the edgeof the tire to the center of the tire, it has the leading edge raised.Seems odd that it switched like that. And I never would have caughtthis with my DOT race tires as the tread stops about an inch from theedge. Any idea what would cause this?Thanks in advance!

Matt


REPLY:

Hi Matt,

Thanks for the email and the kind words. Good eye you have too when looking at tires and yes on race dot's there would not have been any evidence of the changes.

The change on the leading edge from tall to rounded on the side of the tire is due to the valving in the shock itself. It is not uncommon to see both patterns on tires, and in general my thoughts are that when the bike is straight up and down, I don't worry about tire wear too much at that point in the tire. However, we are most vulnerable when we are on the side/edge of the tire so the shock has to work perfectly at that time. Therefore I will always adjust rebound damping based on this criteria to make sure the bike is behaving correctly.

As with all tuning, to get something ou have to compromise with something else, so you can over damp the rear shock in trying to get "perfect tire wear" when seeing this pattern. It is better to make sure that the bike works well at all angles and too much or too little rebound damping which wil affect handling both on corner entry and corner exit.
Please let me know if you have any other questions!

Dave