How to identify the signs of a worn drivetrain

Warning signs from a high stress area of the bike


The freehub isn’t part of the drivetrain, but replacing a worn cassette will involve correctly mounting new sprockets upon it.

Andy warns of the need to install a spacer ‘behind’ the cassette on wheelsets where such is required (the recently tested Swiss Side Franc, and the newly-arrived Mavic Aksium, to name but two). Failure to do so could lead to the cassette damaging the hub, in extreme cases.

Some wheelsets are supplied with a spacer to mount on the freehbu and prevent the cassette from damaging the hub

At the other end of the cassette, Andy advises to check the tightness of the lockring after a first ride. “They can ‘settle’,” he says. An excessively loosened lockring would allow the smallest sprocket to fall off the freehub and damage the frame.

Freehub bodies are highly unlikely to suffer excessive wear. Aluminium bodies are likely to be marked by the pressure of a steel cassette, but such ‘damage’ typically is cosmetic only. Some, higher quality wheelsets have a lightweight steel freehub body. Additionally, higher quality cassettes will contain a ‘carrier’ for some if not all of the sprockets. The Shimano 105 cassette pictured on the previous page has an alloy ‘carrier’ for the three largest sprockets. The remaining seven are individual units, separated by plastic spacers.

Discuss in the forum

Newsletter Terms & Conditions

Please enter your email so we can keep you updated with news, features and the latest offers. If you are not interested you can unsubscribe at any time. We will never sell your data and you'll only get messages from us and our partners whose products and services we think you'll enjoy.

Read our full Privacy Policy as well as Terms & Conditions.