Why hangers bend
By design — sacrificial part to protect the frame in a crash.
Symptoms
Sloppy shifting on big sprockets, derailleur cage rubs spokes, chain jumps off, cage visually leans toward the wheel.
Back|4 minMay 14, 2026 
RepairBike
Bent derailleur hanger: diagnose and straighten
M
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L'Atelier Assistant
Source: Official workshop manuals
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Method
Visual check from behind, then Park Tool DAG-2.2 for accurate alignment. Straighten with long 5mm Allen key — but if you're unsure, replace (10-30€).
Ask the AI mechanic — share your frame brand and exact model, the AI finds the compatible hanger reference.
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