I replaced the rear tire on my bike today, and took the opportunity to add milk jug shims. I should have added four per cush instead of two... maybe next time.
What is the normal shape of the fore and aft section of rubber? Should they have the same dimensions, or is one side thinner than the other? One side of each one was visibly thinner than the other side, and I was wondering if that is from the factory, or from being squished more on one side.