Cycle information - Cranks with 4 chainring bolts
Use these bolt spacings to identify your crank's pcd and smallest chainring.
For other 4 bolt cranks: pcd = 1.4142 × bolt spacing.
- Not all 4 arm 104mm chainrings are interchangeable because their centre diameters vary.
- The minimum size of an Oval depends on its ovality - it is greater for ovalities more than 20% and smaller when less than 20%. The minimum number of teeth for 4-bolt cranks may be estimated as follows:
minimum Oval = minimum round
1 - ( 0.0025 × ovality )
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