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Gearing & Sprockets

Chain Length Calculator

Estimate chain links from sprocket sizes, center distance, and pitch (420 / 428 / 520 / 525). Rounds to an even link count.

Inputs
Results
Live

  • Recommended links

    104links

  • Chain length

    65in

  • Chain length

    1,651mm

  • With +2 spare

    106links

  • Pitch used

    0.625in

Formula

L = 2C + (N+n)/2 + (N−n)² / (4π²C) (C in pitches)

Always confirm with the slack spec in the manual. Add 2 links if you want extra for a larger rear later.

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