Fix guide · Chain & gears

How to Fix Gears That Won't Shift Right

Barrel adjuster, cable and hanger checks

Quick answer

Most shifting problems are fixed by turning the barrel adjuster a quarter turn at a time. If that doesn't work, check the cable and the derailleur hanger.

Close-up of a rear derailleur showing its cable clamp and small adjustment screws — A rear derailleur up close: the cable clamp and the small screws used to set the gears. Photo: Armchair, CC BY-SA 3.0, via Wikimedia Commons (resized)

Try this first

Free, and each takes under 5 minutes.

Shift through every gear
Look at the derailleur from behind

In plain English

Gears shift by a cable pulling the rear derailleur. As the cable stretches or the derailleur gets knocked, the gears get out of tune: slow shifts, noise, or skipping. A small barrel adjuster fixes most of this. A bent derailleur hanger (often from the bike falling over) needs a shop tool.

Watch how it's done

How to Adjust a Rear Derailleur – Limit Screws & Indexing Park Tool · YouTube · loads when you tap play

Video by Park Tool. It may show a regular bike: on an e-bike, switch off and remove the battery first, and unplug the motor cable before taking off a hub-motor wheel.

Step-by-step checklist

Work from the top. Steps go from free and easy to shop jobs. Switch the bike off before touching any connector. Tick each step as you go. Your progress is saved on this device.

1Shift through every gearFree Lift the back wheel, turn the pedals by hand, and shift through all gears. Note where it hesitates or makes noise.
2Look at the derailleur from behindFree Stand behind the bike. The derailleur should hang straight down in line with the cogs. If it leans toward the wheel, the hanger is bent.
3Turn the barrel adjusterEasy If shifting to bigger cogs is slow, turn the barrel adjuster (on the shifter or derailleur) a quarter turn counter-clockwise. If shifting to smaller cogs is slow, turn it clockwise. Test after each quarter turn.
4Check the cableEasy Look for fraying, rust or kinks in the cable and its housing. A dirty or frayed cable makes shifting sluggish and needs replacing.
5Have the gears and chain checkedShop job A shop can straighten a bent derailleur hanger, set the gear limits and replace worn chains and cassettes.

Parts you might need

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Only buy a part if the free steps didn't fix it. Always match the voltage and connector type to your bike.

Brake and shift cable set
Replaces frayed or rusty cables on mechanical brakes and gears.
Link coming soon
Bike multi-tool or hex key set
Fits nearly every bolt on a bike. Useful for almost every guide here.
Link coming soon

Still not fixed?

Pages to try next:

When it's time for a shop: if you've worked through every step and the problem is still there, take the bike to an e-bike shop. Bring your notes on when it happens, plus the code.

Words on this page: UART

Quick answer

Try this first

In plain English

Watch how it's done

Step-by-step checklist

Parts you might need

Brake and shift cable set

Bike multi-tool or hex key set

Still not fixed?