3.1 drivetrain

Measuring Chain Wear

A chain that exceeds wear limits will accelerate cassette and chainring wear. Check every 500–1000 km, more often on e-bikes.

Difficulty ★☆☆ easy
Time ~2 min
Applies to All bikes
Chain wear indicator measurement and replacement thresholds

Tools

  • Chain wear indicator (Park CC-3.2 for 11-speed and below, CC-4 for 12-speed)

Procedure

  1. Wipe the chain clean

    with a rag. Grit hides wear and gives false readings.

  2. Drop the wear indicator into the chain

    — pointed end into one link, the indicator drops into another link several inches away.

  3. Read the result:

    - Indicator falls in completely on the **0.5%** side → the chain has reached 0.5% elongation. For 11-12 speed drivetrains, replace now. - Indicator falls in on the **0.75%** side → chain is fully worn. Cassette is likely also worn. - Indicator does **not** drop in → chain is still good.

  4. For 12-speed chains

    (Shimano 12sp, SRAM Eagle, AXS): use the 0.5% mark as your replacement threshold. These chains are more sensitive to stretch.

  5. Log the date and mileage

    at replacement so the app knows when this chain is due. > If the indicator drops in on the 0.75% side, expect the new chain to skip on the worn cassette. Plan to replace both. ---

A chain that exceeds wear limits will accelerate cassette and chainring wear. Check every 500–1000 km, more often on e-bikes.

Procedure #

  1. Wipe the chain clean with a rag. Grit hides wear and gives false readings.
  2. Drop the wear indicator into the chain — pointed end into one link, the indicator drops into another link several inches away.
  3. Read the result:
    • Indicator falls in completely on the 0.5% side → the chain has reached 0.5% elongation. For 11-12 speed drivetrains, replace now.
    • Indicator falls in on the 0.75% side → chain is fully worn. Cassette is likely also worn.
    • Indicator does not drop in → chain is still good.
  4. For 12-speed chains (Shimano 12sp, SRAM Eagle, AXS): use the 0.5% mark as your replacement threshold. These chains are more sensitive to stretch.
  5. Log the date and mileage at replacement so the app knows when this chain is due.

If the indicator drops in on the 0.75% side, expect the new chain to skip on the worn cassette. Plan to replace both.