Motorcycle Chain Wear Calculator
Check if your motorcycle chain is worn and needs replacement.
Enter measured chain length and compare to spec to calculate stretch percentage and remaining life.
Motorcycle Chain Wear Formula
Stretch % = ((Measured Length − Spec Length) / Spec Length) × 100
Chains are typically measured across a fixed number of links (usually 20 or 21 links) with the chain tensioned but not under load.
Replacement thresholds:
- Under 0.5% stretch: Like new — keep riding
- 0.5% to 1.0% stretch: Monitor closely — inspect sprockets
- 1.0% to 1.5% stretch: Replace chain and inspect sprockets
- Over 1.5% stretch: Replace immediately — chain and sprockets
The standard measurement: Most manuals give a spec in mm for a set number of pins/links (e.g., “20 links = 317.5 mm new”). Measure yours with the same link count and compare.
Chain pitch: 520, 525, and 530 are common motorcycle chain sizes. Each link pitch is slightly different.
- 520 chain: 15.875 mm pitch (20 links = 317.5 mm new)
- 525 chain: 15.875 mm pitch (same pitch as 520, stronger plates)
- 530 chain: 15.875 mm pitch
Always replace sprockets with the chain — worn sprockets destroy new chains within miles.