How to mend a bicycle puncture
You’ll need a pump, tyre levers and a puncture repair kit with patches, sandpaper, a marker and glue.
1. Turn the bike upside down so you can take off the wheel. Use the quick-release lever if you have one or, if the wheel is bolted on, undo with a spanner. Check the tyre for any obvious causes of a puncture, such as a thorn or glass, and remove.
2. Insert the flat end of the tyre lever into a gap between the tyre and the wheel rim, on the opposite side of the valve. Then hook the other end of the lever on a spoke. Take the next lever and do the same about 5cm further around the tyre. Repeat until one side of the tyre is free from the rim.
3. Gently pull out the inner tube. Keep working your way around. Check the inside of the tyre for anything that might have caused the puncture and remove.
4. Locate the puncture by squeezing the inner tube and listening for escaping air. If you’re struggling to hear, put the tube in water and you will see bubbles. Once you’ve found the puncture, mark the spot with a crayon or marker. Use the sandpaper in your repair kit to roughen the area. Make sure it’s dry and follow the instructions on the packaging to stick on the patch.
5. Pump up the tube slightly before putting it in position, with the valve through the wheel. Tuck the tube into the tyre all the way around. Starting at the valve side, use the levers to tuck the tyre over the wheel. Be careful not to pinch it. Inflate the tyre and put the wheel back on.