Motorcycle Chain Wear Calculator
Check if your motorcycle chain is worn and needs replacement.
Enter measured chain length 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.