Symptoms
- Shifting becomes inconsistent or stops working in one direction
- Visible frayed strands at the cable end
- Cable snapped completely, leaving the bike stuck in one gear
- Cable catches or binds inside the housing
Likely causes
- CommonNormal wear and fatigue over timeCables flex thousands of times and eventually fray, especially at sharp bend points.
- CommonRust from water exposure without maintenanceMoisture inside the housing can corrode and weaken the cable strands.
- PossibleSharp bend or kink point in the housing routingA tight bend concentrates stress and accelerates fraying at that point.
What to do
- If the cable has snapped, note which gear the bike is stuck in, since this helps with the repair process.
- Remove the remaining cable pieces from the shifter and derailleur, noting the routing through the frame and housing.
- Purchase a replacement cable and matching housing if the old housing is also worn or corroded.
- Thread the new cable through the shifter, through the housing sections, and to the derailleur pinch bolt.
- Set initial cable tension with the barrel adjuster and secure the cable at the derailleur pinch bolt.
- Shift through all gears to fine-tune tension and confirm smooth, accurate shifting.
- If you're not comfortable with cable routing and tensioning, a bike shop can replace the cable and tune the shifting quickly.
Tools and parts
- Cable cutters
- Allen key set
- Replacement cable and housing
Derailleur shift cable and housingSearch: “bicycle shift cable and housing kit”
When to call a pro
A bike shop can replace the cable and properly tune the derailleur indexing, which sometimes takes a few small adjustments to get exactly right.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.