TUTO - How can you tell if your cassette and chain are worn ? | Decathlon, by Decathlon EN on YouTube. 3 min.
- Video length
- 3 min
- Time to do it
- 10 minutes
- Difficulty
- Easy
- Steps
- 9
What you need
Steps
Shift onto the big chainring at the front and the smallest sprocket at the back. This puts the chain under tension so the measurement is accurate.
Wipe the chain with a rag so grit does not throw off the tool. Check the chain is clean and dry before you measure.
Push the tool's first pin into a chain link. Let the tool sit flat against the chain so both pins line up with the rollers.
Drop the second pin into the chain a few links away. The tool should sit straight, not tilted, for a true reading.
Read the result. If the tool sits flat and drops in easily with no gap, the chain is still healthy and in the OK zone.
If the tool shows moderate wear in zone 1, plan to replace the chain soon. A worn chain wears the cassette faster.
If the tool falls into zone 2, the chain is critically worn. Replace the chain and the cassette together to avoid skipping.
Look at the cassette teeth. Pointed, hooked or shark fin shapes mean the cogs are worn and need replacing.
Check the chain again every few hundred kilometres, or sooner if shifting feels rough or you hear rattling.
Tips and common mistakes
A worn chain is the main cause of cassette damage, so check it often rather than waiting for symptoms.
Measure at several points around the chain, since wear can be uneven.
Replace the chain before it reaches zone 2 to save the cost of a new cassette.
Keep the chain clean and lubricated to slow stretch and keep shifting crisp.
Questions
How often should I check my chain?
Check it every few hundred kilometres, and always when shifting gets rough or you hear new noises. A quick check takes under a minute.
Can I replace just the chain if my cassette looks fine?
Yes, if the tool shows only moderate wear and the teeth look even. If the chain is in zone 2 or the teeth are pointed, replace both together.
What are shark teeth on a cassette?
They are cogs whose teeth have worn into pointed, hooked shapes. That means the cassette is worn and will not hold a new chain well.
This guide was drafted from the video's details and general task knowledge. It has not been checked against the full video. Check the video and relevant product instructions before following a procedure. Report a correction.
