Chainline is the angle of a bicycle chain relative to the centerline of the bicycle frame.[1] A bicycle is said to have perfect chainline if the chain is parallel to the centerline of the frame, which means that the rear sprocket is directly behind the front chainring.[1] Chainline also refers to the distance between a sprocket and the centerline of the frame.

Chainline on a fixed-gear bicycle

Bicycles without a straight chainline are slightly less efficient due to frictional losses incurred by running the chain at an angle between the front chainring and rear sprocket.[1] This is the main reason that a single-speed bicycle can be more efficient than a derailleur geared bicycle. Single-speed bicycles should have the straightest possible chainline.[2]

See alsoEdit


  1. ^ a b c Sheldon Brown, John Allen (04/05/2012). "About Bicycle Chainline". Retrieved 2013-03-16. Check date values in: |date= (help)
  2. ^ Sheldon Brown (2011-11-22). "Fixed Gear Conversions". Retrieved 2013-03-16. with a fixed-gear setup. It is quite important to get the chain line just right.