How do I fix a bike puncture?

Fixing the tube is straightforward. The part that determines whether the repair lasts is finding the thorn, glass fragment or spoke end still in the tyre — which is invisible from outside and obvious from within.

What you'll need

• Tyre levers
• Spare tube or patch kit
• Pump
• Bowl of water (optional)

Step by step

1. Remove the wheel and let all the air out.Fully deflate before trying to get the tyre off. A partly inflated tyre is far harder to remove.
2. Lever the tyre off one side only.Two levers, a few centimetres apart, working around the rim. Leaving the other side seated makes refitting much easier.
3. Pull out the tube and inflate it to find the hole.Listen and feel for escaping air. If you cannot find it, pass it through water and look for bubbles.
4. Note where the hole is relative to the valve.This is the key step. It tells you exactly where on the tyre to look for the cause.
5. Run your fingers carefully around the inside of the tyre.Slowly, and be careful of sharp objects. You are looking for a thorn, glass, wire or a protruding spoke. This is the step that makes the repair last.
6. Check the rim tape too.A hole on the rim side of the tube means the rim tape has slipped and a spoke hole is cutting it. Replace or reposition the tape.
7. Fit the new or patched tube with just enough air to hold its shape.It stops it twisting and reduces the chance of pinching it under the tyre bead.
8. Refit the tyre by hand where possible and inflate gradually.Levers can pinch the tube. Inflate part way, check the bead is seated evenly all round, then inflate fully to the pressure on the sidewall.

Tips

• Carry a spare tube rather than only a patch kit. Swapping a tube at the roadside is far quicker; patch the old one at home.
• Two punctures close together on the inner side, often called a snakebite, means the tyre was under-inflated and pinched against the rim. Check your pressures.
• Inflate tyres to the pressure printed on the sidewall. Correct pressure prevents most punctures and makes riding noticeably easier.

Common mistakes

• Not finding what caused the puncture — The thorn or glass is still in the tyre, and the new tube punctures in the same place within a short distance.
• Using tyre levers to force the tyre back on — They pinch the tube against the rim and cause a new puncture immediately. Get it on by hand where you can.
• Inflating fully before checking the bead — An unevenly seated bead causes a bulge and can blow the tyre off the rim. Check at low pressure first.

Questions people ask