Help me understand chainline and crankset compatibility
 

Hoping someone can clarify something for me. Assuming the chainring and single-speed freewheel are both 1/8" or 3/32", is the compatibility for a singlespeed build or conversion simply a matter of making sure the chainlines for the crankset and the freewheel are identical? Let's say I have a wheel with one of the Surly flip-flop hubs with a chainline of 53.5mm – can I just use any crankset that has a similar chainline?

That's all there is to it!

Keep in mind it doesn't have to be exactly the same. I've run 3/32" drivetrains with 4-5mm of mismatch in chainline and never had any issues. 1/8" or dedicated singlespeed 3/32" chains are going to be a little less tolerant since they don't flex as much laterally but I've only ever used regular 3/32" multispeed chains with no issues. You can have a pretty large mismatch - just think about how much chain deflection modern mountain bike drivetrains have to deal with, but the straighter the chain the better. Straight chains make a quiet drivetrain :thumb:

Thanks! Appreciate it.