Gear indexing and derailleur repair
Indexing, cable replacement, hanger alignment and full gear sets — front and rear.
Gear problems frustrate riders more than almost anything else on a bike, partly because the obvious suspect is usually innocent. The derailleur gets blamed; the chain is normally the culprit.
The single most useful diagnostic is when it goes wrong. Skipping only under power is wear. Hesitating or refusing to reach certain gears regardless of effort is adjustment — cable tension, limit screws, or a bent hanger.
Why we measure before quoting
Chain wear is measurable, not a matter of opinion. A gauge tells us in seconds whether you are looking at a AED 45 adjustment or a AED 135 drivetrain job, and the difference matters. Anyone quoting for skipping gears without measuring the chain first is guessing.
Sand and cable housing
Gear cables run in housing that is open at both ends. Fine sand gets in, packs down, and the cable starts dragging. The symptom looks exactly like cable stretch — shifting that got gradually worse — but tightening the barrel adjuster only masks it. New housing is the fix, and it lasts.
What the job involves
Diagnosis first
- Chain wear measuredWith a gauge, before anything is quoted. It decides whether this is an adjustment or a drivetrain job.
- Hanger checked for alignmentA bent hanger makes indexing impossible to hold, and it is invisible by eye.
The adjustment
- Limits resetHigh and low stops set so the chain cannot reach the spokes or drop off the small sprocket.
- Indexed under loadSet up while pedalling against resistance, because that is when skipping actually happens.
- B-tension setJockey wheel spacing corrected so the biggest sprocket shifts cleanly.
When this is not the job you need
A repair business that only ever says "book it in" is not worth trusting on anything else. These are the cases where you should not.
- If the chain is past its wear limit, indexing will not hold and we will tell you so rather than take the money twice.
- Skipping only in one gear on an otherwise healthy drivetrain is often a single damaged sprocket, not a full replacement.
- A dropped chain at the front is a limit-screw job, not a gear service.
Symptoms that lead here
Common questions
Why do my gears skip only when I pedal hard?
Light pedalling does not put enough force on the chain to make it climb worn teeth. Load is what exposes wear, which is why it shows up on hills and pulling away from lights first. That pattern usually means drivetrain wear rather than adjustment.
Can you index gears at my home?
Yes. Indexing, cable replacement and hanger alignment are all done at your door on a workstand. It is one of the most common jobs we do.
Do I need a new cassette as well as a chain?
Only if the chain was ridden well past its wear limit, in which case the cassette has worn to match and a new chain will skip on it immediately. We measure before quoting so you are not paying for both unnecessarily.