Safe to keep ridingWarning sign
Rattling From the Derailleur
A metallic rattle from around the rear wheel, worse over bumps.
What's happening
A loose, tinny rattling noise that seems to come from down by the cassette, especially noticeable over rough ground.
Likely causes
- •Worn jockey wheel bearings inside the derailleur cage
- •A loose derailleur mounting bolt
- •A bent derailleur hanger allowing extra movement
What to do
Safe to ride, but get it checked soon — a derailleur that's moving more than it should risks a chain jam or a snapped hanger.
Heads up: Bikeautonomy is for general guidance only. If your bike is behaving oddly, get it inspected by a qualified bike mechanic.