By: Anonymous: Harvey () Tuesday, 27 January 2015 @ 06:40 AM ICT (Read 665 times)
Why are the tread patterns on some front motorcycle tires reversed compared to rear tires, and to the tread patterns on car tires? It seems like the tread channels water toward the center of the tire rather than away from it.
The reason we have tread patterns on tires is to give water a place to go when we ride in the wet. The trade-off with having patterns of grooves on our tires is that the patterns can concentrate wear and sometimes lead to irregular wear.
How a tire helps get us through water is very complicated, and although there is an aspect of the tire 'pushing water out of the way,' the pattern doesn't channel water as much as it just gives the remaining water a place to go. So, although a 'reversed' front pattern may look like it will channel water 'in,' it really doesn't.
This leads us to the reason that the front patterns generally are 'reversed' from the rear tire patterns. It has to do with the other aspect of tread patterns – wear – and the forces acting on fron and rear tires. The main force acting on a front tire is a braking force, while the main force acting on a rear tire is traction force. These two forces act in the opposite direction from each other, and basically that is why the patterns are opposite of each other, to best resist these forces leading to irregular wear.