Originally Posted by
700wheel
We are discussing different things. I was talking about tooth thicknesses. I just measured 3/32 and 1/8 Campagnolo cogs; dimensions were 0.085 and 0.112 respectively. So actual contact area for 1/8 tooth is 32% greater than 3/32 tooth.
It doesn't matter, tooth thickness and roller/inner width are two titles on a same story.
A chain doesn't elongate due to wear of the outside of a roller or a tooth, it elongates due to wear on the mating surfaces between certain inner parts of the links and next links. Thicker plates and accordingly longer pins increase those surfaces, which decreases elongation for a same amount of worn off material.