Did you know that virtually every motorcycle tire will wear more rapidly on the left side than the right? So what’s the cause? The rotation of the earth? Strange motorcycle voodoo? Well, no. There are actually two distinct factors that cause this phenomenon.
The first reason for accelerated left side tire wear is the nature of our roads. Virtually every road in America is crowned for water runoff. A road needs to shed water to the sides for safe driving in wet conditions. The severity of the crown varies widely by road type and region, but you are almost always riding on the side of an asphalt hill. Since we drive on the right side of the road, the left sides of our tires carry more of the traction burden.
The second reason for increased left-side tire wear is also a result of driving on the right side of the road. Every normal left turn (to a right-side rider) is wider than the corresponding right turn. Since left turns are wider, most riders carry substantially more speed into them. With increased cornering speed comes increased side tread wear. The slower pace of the tighter right turns creates less wear.
So there you have it - there are tangible reasons as to why you reach the tread-wear indicator faster on the left side of your tires, and it has nothing to do with the rotation of the earth!
