Originally Posted by
RubeRad
It's an issue of width.
Single-speeds/fixies use I believe the oldest chainwidth standard, same as the old ten-speeds (5 cogs).
No, ten-speed bikes (with 5 cogs in rear) use 3/32" chains whereas bikes with single cogs in the rear (one-speeds, three-speeds, etc) use 1/8" chains. The 1/32" difference in width makes a big difference in durability. So does the fact that you don't shift a 1/8" chain, as shifting causes wear.