Drivetrains - 3/32 vs 1/8

cog Most modern bike drivetrains use gears 3/32" (inch) wide, and chains to match.  Some, however, use gears 1/8" wide.

As we add more speeds, the cogs get squished closer together, but they're still 3/32".  That means the plates of the chain need to get thinner, because the inside gap must stay at 3/32".   That's why the tolerance for error on a 10 speed chain installation is much less than that of an 8 speed. 

1/8" drivetrains are usually used on BMX bikes and sometimes track bikes.  Everything is a little more beefy, which makes the chainrings and cogs a little more durable.  It's questionable if a 1/8" chain is stronger than a 3/32" chain, not factoring in crazy stuff like grinding a chain on a railing or something like that.  It's best to just match your drivetrain (sprokets and cogs).

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8 speed FTW!
# Posted By Steven | 2/7/08 5:38 AM