CoachingAnswer

HOW DO I INDEX MY GEARS PROPERLY?

By Anthony WalshRoadman CyclingUpdated 10 July 2026

ANSWER

Gear indexing aligns the derailleur with each sprocket so shifts are clean and silent. The process involves checking cable tension via the barrel adjuster on the rear derailleur or shifter. If the chain hesitates shifting to a larger cog (harder to pedal direction), turn the barrel adjuster anti-clockwise by quarter-turns to increase tension. If it hesitates shifting to a smaller cog, turn clockwise to reduce tension. The adjustment is small — a quarter-turn at a time — and should produce immediate improvement. Most indexing problems stem from cable stretch, which occurs naturally in the first few hundred kilometres on a new cable.

KEY TAKEAWAYS

Barrel adjuster adjustments are the primary tool — quarter-turn increments are usually sufficient.
Chain hesitating upward (to larger cogs) means not enough cable tension — turn anti-clockwise.
Chain hesitating downward (to smaller cogs) means too much tension — turn clockwise.
New cables stretch in the first 200-500km, causing indexing to drift — a single barrel adjuster tweak typically fixes it.

WHO THIS IS FOR

IS THIS YOU?

Riders with noisy or imprecise shifting who want to fix it themselves

Your gears click, hesitate, or skip under load and you want to resolve it without a trip to the bike shop.

Cyclists with a new bike or new cables experiencing shifting drift

Your bike shifted perfectly when new but has gradually become less precise as cables bedded in.

THE ROADMAN VIEW

Gear indexing is one of those skills that sounds technical but is actually one of the simplest adjustments on a bike. If your gears are clicking or hesitating, 90% of the time it is a cable tension issue that takes 30 seconds to fix with a barrel adjuster. You do not need special tools and you do not need to be mechanically gifted.

The key insight is that the barrel adjuster is all you need for routine adjustment. Limit screws and B-tension only come into play during initial setup or after a derailleur replacement. If your gears were working and have gradually drifted, the barrel adjuster alone will bring them back.

EXPERT EVIDENCE

WHAT THE EXPERTS SAY

Calvin JonesDirector of education, Park Tool
The vast majority of shifting problems brought to bike shops are resolved with a quarter to half turn of the barrel adjuster — a 30-second fix. Cable tension is the single most common cause of poor shifting, and it occurs naturally as cables stretch and housing compresses over the first few hundred kilometres of use. Teaching riders to make this adjustment themselves eliminates the most frequent reason for a workshop visit.

PRACTICAL APPLICATION

DO THIS WEEK

Identify the shifting problem while riding or on a stand
Shift through the full cassette while pedalling. Note whether the chain hesitates moving to larger cogs (toward the wheel) or smaller cogs (toward the frame). Hesitation upward means cable tension is too low; hesitation downward means tension is too high. If the chain shifts well in one direction but not the other, it is almost certainly a tension issue.
Adjust cable tension with the barrel adjuster
Locate the barrel adjuster — it is the knurled ring where the cable enters the rear derailleur or on the shifter body. Turn it anti-clockwise (away from you, viewing from behind) in quarter-turn increments if shifting up is hesitant. Turn clockwise if shifting down is hesitant. Pedal and shift after each quarter-turn to test. The correct setting produces silent, instant shifts across all gears.
Check cable and housing if barrel adjustment does not resolve the issue
If a full range of barrel adjustment does not fix the shifting, inspect the cable for fraying (especially at the pinch bolt) and the housing for kinks or splits. Contaminated or corroded cables create friction that mimics a tension problem. Replace cables and housing every 12-18 months or sooner if exposed to heavy rain and grit.

COMMON MISTAKES

WHAT CYCLISTS GET WRONG

MISTAKEAdjusting limit screws when the problem is cable tension.
FIXLimit screws prevent the derailleur from shifting the chain off the cassette. They rarely need adjustment after initial setup. If your gears were working and have drifted, the barrel adjuster is the correct fix. Touching limit screws when cable tension is the issue creates additional problems.
MISTAKEMaking large adjustments instead of quarter-turn increments.
FIXGear indexing is precise — a full turn of the barrel adjuster is a large change. Start with a quarter-turn, test by shifting, then add another quarter-turn if needed. Overshooting creates the opposite problem and sends you back and forth.
MISTAKENot checking the derailleur hanger alignment.
FIXA bent derailleur hanger causes inconsistent shifting that no amount of cable adjustment can fix. If your bike has been crashed or the derailleur has been hit, check the hanger alignment with a hanger alignment gauge or have a shop do it. A replacement hanger costs £15-30 and is specific to your frame.

FAQ

FREQUENTLY ASKED QUESTIONS

How often do gears need indexing?

New cables typically need re-indexing after 200-500km as they stretch. After that, cable tension remains stable for months unless exposed to extreme conditions. Most riders need a barrel adjuster tweak every few months at most. If your gears need constant re-indexing, suspect a cable, housing, or hanger problem.

Is indexing electronic gears different?

Electronic groupsets (Shimano Di2, SRAM AXS, Campagnolo EPS) do not use cable tension. Indexing is done through the electronic interface — Di2 uses junction-box button presses, SRAM AXS uses the app. The principle is the same (aligning the derailleur with the cogs) but the adjustment is digital rather than mechanical.

Can I index gears without a bike stand?

Yes. Lean the bike against a wall, lift the rear wheel, and pedal by hand while shifting. Alternatively, flip the bike upside down (use a towel under the saddle and bars to prevent scratching). A bike stand makes it easier but is not required for a barrel adjuster tweak.