Originally Posted by
Tourist in MSN
I always want my best tire on the front. When the rear wears out, the front goes to the back and the new one goes on the front.
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I've seen this advice a lot of places, including if I am not mistaken from Sheldon Brown.
The idea is that the front tire does more of the work of braking and steering - safety critical functions - so you don't want to move a worn tire from the back to the front.