Symptoms
- Derailleur visibly angled inward toward the wheel
- Loud clicking or grinding from the derailleur touching spokes
- Shifting suddenly got much worse after a fall or chain jam
- Chain skips badly in multiple gears
Likely causes
- CommonBent derailleur hangerThis small, intentionally sacrificial part bends to protect the frame and derailleur in a fall or jam.
- PossibleBent derailleur cage itselfA harder impact can bend the derailleur body, not just the hanger.
- PossibleBroken derailleur from severe impactIn serious cases, the derailleur can crack or shatter, especially if it got caught in the spokes at speed.
What to do
- Stop riding immediately if you hear grinding or see the derailleur near the spokes, since continuing can cause more damage or a wheel lock-up.
- Inspect the derailleur hanger visually by looking at it from behind the bike to see if it's bent inward or outward.
- If a hanger alignment tool is available, use it to check and correct minor bends per the tool's instructions.
- Check the derailleur cage and pulleys for cracks or bending, which indicate a more serious impact.
- If the hanger is only slightly bent, careful hand pressure can sometimes correct it, but this risks snapping it if forced too far.
- Shift through all gears carefully after any adjustment to confirm the chain isn't rubbing or skipping.
- For anything beyond a very minor bend, or if the derailleur itself looks damaged, take it to a bike shop rather than risk further damage.
Tools and parts
- Derailleur hanger alignment tool (for bike shop use)
Derailleur hangerSearch: “bicycle derailleur hanger replacement”
Rear derailleurSearch: “bicycle rear derailleur replacement”
When to call a pro
A bike shop can straighten a hanger precisely with the correct tool or replace it, since hangers are inexpensive and specific to your frame.
Safety
Use caution
Stop riding if the derailleur is contacting the spokes, since it can lock the rear wheel suddenly and cause a fall.