How to Fix a Puncture, Step-by-Step Guide

Introduction

Punctures happen. They happen on cold Tuesday commutes, on Sunday rides twenty miles from home, and five minutes into the ride you have been looking forward to all week. Knowing how to fix one transforms a puncture from a disaster into a ten minute pause. It is the single most useful mechanical skill any cyclist can learn.

The good news is that fixing a puncture requires no special talent. If you can peel a sticker, you can patch a tube. The key is practising at home before you need to do it on the roadside in the rain with numb fingers.

What You Need

Carry these on every ride. No exceptions.

Spare inner tube. Matched to your wheel size and valve type (Presta or Schrader). Costs around five pounds. A spare is faster than patching roadside.

Tyre levers. Plastic, not metal. Metal levers damage rims and pinch tubes. Three is ideal. Two works. Park Tool or Pedro's make good ones for under five pounds.

Mini pump or CO2 inflator. A pump is slower but never runs out. CO2 cartridges are fast but single use. Carry at least two cartridges if going the CO2 route.

Patch kit. Backup for your spare tube. Includes self-adhesive patches, sandpaper, and glue patches. Rema TIP TOP is the gold standard.

Tyre boot. A section of old tyre or a Park Tool tyre boot, for when the tyre itself has a cut. Rare but saves your ride when it happens.

Removing the Wheel

Rear Wheel

The rear wheel intimidates beginners because of the chain and gears. It is simpler than it looks.

1. Shift to the smallest cog before stopping. This moves the derailleur out of the way and makes refitting easier.
2. Open the quick release lever or loosen the thru axle. Quick release: flip the lever to the open position. Thru axle: unthread anticlockwise.
3. Lift the rear of the bike and guide the wheel down and forward, letting the chain drop off the cassette.

Front Wheel

Open the quick release or thru axle. On rim brakes, release the brake caliper first using the small lever on the brake itself. Disc brakes need no adjustment, just be careful not to squeeze the brake lever while the wheel is out.

Finding and Fixing the Puncture

Removing the Tyre

1. Deflate the tube completely by pressing the valve core (Presta: unscrew the tip and press; Schrader: press the pin).
2. Insert a tyre lever under the bead opposite the valve. Hook it onto a spoke.
3. Slide a second lever along the rim to unseat one side of the tyre.
4. Pull the tube out, starting opposite the valve. Remove the valve last by pushing it through the rim hole.

Finding the Hole

Inflate the tube and listen for hissing. If you cannot hear it, pass the tube slowly past your lips, they are more sensitive than fingers. Still nothing? Submerge the tube in water and watch for bubbles.

Check the tyre itself. Run your fingers carefully along the inside surface feeling for thorns, glass, or wire. Whatever caused the puncture may still be embedded in the tyre. Remove it or you will puncture again immediately.

Fitting a New Tube

1. Slightly inflate the new tube so it holds its shape, just enough that it is not floppy.
2. Insert the valve through the rim hole first.
3. Tuck the tube into the tyre all the way around, ensuring it is not twisted or pinched.
4. Starting at the valve, push the tyre bead back onto the rim using your thumbs. Work away from the valve in both directions.
5. The final section will be tight. Push the valve up into the tyre to prevent the tube getting trapped under the bead, then roll the last section on with your palms. Avoid tyre levers for refitting, they risk pinching the new tube.
6. Before inflating fully, check both sides of the tyre all the way around. If you can see tube bulging between tyre and rim, deflate and reseat.

Inflating

Pump to the pressure shown on the tyre sidewall. Road tyres typically run 80 to 100 psi. Mountain bike tyres run 25 to 35 psi. Hybrid tyres sit around 50 to 70 psi.

Patching Instead of Replacing

Save patching for at home or when you have used your spare tube.

1. Find the hole.
2. Roughen the area around it with sandpaper, slightly larger than the patch.
3. Apply a thin, even layer of vulcanising glue. Wait two to three minutes until the glue becomes tacky and slightly matte.
4. Press the patch firmly onto the glue. Hold for thirty seconds.
5. Wait another minute before inflating.

Self-adhesive patches work as an emergency fix but are less reliable than glue patches for long-term use.

Preventing Punctures

Tyre pressure. Check weekly. Under-inflated tyres pinch-flat on potholes. Over-inflated tyres lose grip and ride harshly.

Tyre condition. Replace when tread wears flat or sidewalls show fraying. Worn tyres puncture dramatically more often.

Tyre sealant. Brands like Muc-Off and Stan's seal small holes automatically. Works with tubes and tubeless setups. Messy but effective.

Puncture-resistant tyres. Schwalbe Marathon Plus and Continental Gatorskin are the gold standards for commuters. Heavier but worth the trade-off for daily riding.

Line choice. Avoid drains, gutters, and the very edge of the road where glass and debris collect. Riding slightly further into the lane is both safer from traffic and from punctures.