Fix a flat on a tube-type wheel
The core off-road repair. Practise it once in the garage before you need it on a hillside, and time yourself.
What you need
- — Tire levers (2–3) and rim protectors
- — Axle wrench for your bike, plus a 12/13 mm for the rim lock and valve nut
- — Spare tube and/or patch kit with fresh vulcanising glue
- — Trail stand or something to prop the bike
- — Pump, compressor or CO2 and a pressure gauge
Steps
- 01Get the wheel off the ground on the stand, note the chain adjuster position, and pull the axle.
- 02Deflate fully: remove the valve core, then loosen the rim lock nut so the bead can drop into the well.
- 03Break both beads by standing on the tire, then lever one side off using short strokes and rim protectors.
- 04Pull the old tube, then run your fingers around the inside of the carcass to find the thorn, nail or spoke end that caused it — otherwise the new tube fails within kilometres.
- 05Dust the new tube with talc, fit it with a little air in it so it holds shape, and start the valve through the rim first.
- 06Lever the bead back on working away from the valve, keeping the tube pushed away from the bead so you don't pinch it.
- 07Inflate to seat the beads, check the bead line is even all the way round, then set pressure and tighten the rim lock.
- 08Refit the wheel, reset chain tension to your marks, and torque the axle as hard as your kit allows. Recheck after 20 minutes of riding.
Watch out
- — A pinched tube is the most common failed repair — never lever near the valve with the tube unsupported.
- — Patch the tube you removed and keep it as the next spare, rather than carrying a dead tube around.