Cal Moto Industry Tips & Tricks - Technical Tips Tire wear...
how it looks, how it occurs. Why is it that your front tire
wears more on the left side than the right? It is because most
of the roads in America have a significant crown, and when
driving straight ahead, you are traversing a side hill, and must
constantly correct to the left to keep the bike rolling
straight. This affects only the left side of the front tire. A
further characteristic of front tire wear is that front tires
wear mainly in the area about 1/3 of the way around the profile
of the tire. (A worn front tire has a profile like a snowplow,
rather than a round arc.) The center of the tire almost never
shows much wear. The sides wear because they take all the forces
of directional control, and the tread of the tire at the edges
of the contact patch also squirms laterally as the tire rolls
straight down the road. The rear tire, on the other hand, almost
always shows the greatest wear right in the middle, since the
main forces on the rear tire