What you need
To fix a puncture, you’ll need tyre leavers, a pump (make sure it’s set up for the valves on your tyres), a repair kit (sandpaper, glue, chalk and patches) and / or a spare inner tube. Unless you have quick-release wheels, you’ll need a spanner

What to do
It’s far easier to fix a flat with the wheel off the bike, so start by disconnecting the brakes and removing the wheel from the bike.

1. Remove the valve cap (and, for Presta valves, the locknut at the base).
If air remains in the tyre, deflate it by pressing the pin at the top (for Presta valves, first unscrew the nut on the pin)

2. Use tyre levers to remove one side of the tyre from the wheel rim.

3. Slip the valve through the hole in the rim and remove the inner tube from the tyre.

4. To locate the puncture, pump air into the tube and listen for air hissing out. If the puncture is really small, you might need to submerge the tube in a tub of water and look for bubbles to find the hole. Once you’ve found the puncture, mark it with chalk, then examine the tyre to find the cause of the puncture. Remove any sharp objects like shards of glass or nails.

5. Use sandpaper or a metal rasp on the area immediately surrounding the puncture. This cleans dirt away and helps the patch to adhere.

6. Choose a suitable sized patch (smaller is usually better). Apply an even coating of glue to an area slightly larger than the patch. Allow the glue to dry until it’s tacky to the touch (about five minutes).

7. Remove foil from the back of the patch and press the patch firmly over the puncture, maintaining pressure for around a minute. Use the rounded edge of a tyre lever or your fingernail to press down the edges of the patch. The patch should fuse completely with the tube, leaving no loose edges.

8. To refit the tube in the tyre, it helps to replace one side of tyre onto the wheel rim. Inflate the tube just a little – so that it holds some shape. Position the valve through the hole in the rim, ensuring it’s straight and not on a slant. Fit the tube evenly back into the tyre. Don’t squash the tube – if it seems too big, deflate it slightly and work it around.

9. Work the tyre back onto the wheel rim. First check that the rim tape still covers the spoke nipples (bolts) in the rim. Next, hold the wheel in front of you with one side of the tyre sitting on the wheel rim and the tube fitted inside. The valve should be straight. Use your thumbs to work the tyre onto the rim, starting at the valve. Avoid pinching the tube between the tyre and the rim. If necessary, deflate the tube a little towards the end and, if it’s still too tight, use tyre levers to ease the last section onto the rim – carefully.

10. If necessary, check the tube isn’t pinched between the tyre and the rim: work around both sides of the tyre, pulling it back to look (a pinched tube will explode loudly when it’s pumped up).

11. Pump up the tyre (replacing the locknut on Presta valves). On Presta valves, tighten the nut after pumping. Replace the valve cap.

12. Replace the wheel and reconnect the brakes.