On my commuter bike I get insane life out of a chain, but it's an 1/8" singlespeed drivetrain. Built for a beatdown.
My CX bike is the same setup, but due to CX race conditions (lots of stompy sprints, sand, mud, crashing in a big heap of bicycles) the race chain will last a single season.
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"I feel like my world was classier before I found cyclocross."
- Mandi M.