How to fix a bicycle puncture

Before you get started fixing the puncture you'll need the following bits of kit: • a tyre lever (sometimes two) • a spare inner tube • a pump - with its fitting set up to suit the valves on your bike - (presta or schraeder valves).

The first thing to do is to consider your location. It might take ten minutes or more to fix your puncture, so position yourself somewhere safe and comfortable. If you’re riding in the sunshine somewhere like Croatia, Greece, Italy or Sardinia maybe find a shady tree - or even better, a café where you can have a refreshing drink while you work.

For a front wheel: Open the quick release lever, then hold the small nut the other side, and untwist the lever around 4 or 5 turns - until you can lift the front of the bike and the wheel simply drops out.

For a rear wheel: Put the rear gears into their highest setting, using the shifter on the right hand side of your handlebars, then pedal round until the chain is sitting on the smallest sprocket. Open the quick release lever. (On some Trek bikes, if there’s an ‘ABP’ sticker on the frame, you may have to unscrew the lever after you’ve opened it, until it comes fully out of the bike, attached to a threaded ‘skewer’.) Now lift the rear of the bike. Gravity should help the wheel drop out, but you may need to tap the top of tyre, or move the chain out of the way to help the wheel come free.

With the wheel now freed from the bike, it’s time to look for anything that may have caused the puncture. 

Take a tyre lever, and with the pointed end, place it between the rubber of the tyre and the metal of the rim, and then lever it down. You may now be able to slide the tyre lever sideways and release the tyre. If that’s not possible, hook the tyre lever onto a spoke, and use an additional one, a few inches along, which you can then slide round.

There’s no need to fully remove the tyre from the wheel. Once one side is free, you’ll be able to remove the inner tube from the tyre. If your bike has presta valves, unscrew the lockring that holds the valve in position first. Carefully check the inside of the tyre for thorns, stones, glass or anything else that could have caused your puncture. If you miss it, you’ll just puncture your new tube all over again!

Take a new tube and use your pump to put just a small squirt of air into it. For presta valves, you’ll need to loosen the tiny nut at the end of the valve first. Then remove the pump and (on presta valves) the little lockring, slot the valve into its hole in the rim, and position the tube into the tyre. Replace the lockring if it’s a presta valve.

Starting near the valve, use your thumbs to position the hard edge of the tyre back into its groove behind the metal rim. Work around in both directions, moving your hands further apart as your thumbs slot the tyre into position.

When this becomes difficult, turn the wheel so the last gap in the tyre is positioned at the top. Use both your thumbs to pop the last section of tyre into place. If this is tough, try pinching the tyre together all around the rest of the wheel - this might free up a little slack for you.

Inflate your tyre. Attach the pump to the valve and pump until the tyre starts to firm up. Stop and check that everything is still in place where the tyre meets the rim - on both sides. Keep pumping and checking. If the tyre looks lopsided, deflate, push things into position, then try again. For a road bike, keep pumping until the tyre is very firm. For a mountain bike, the tyre should have some ‘give’ when you squeeze the sides, but it should take a bit of effort from your fingers. On presta valves, do up the little nut at the end when you’ve finished pumping - not too tight.

For a front wheel: Hold the wheel on the ground, then pick up the bike and slot the fork onto the wheel. If the bike has disc brakes, be sure to slot the disc carefully into its caliper. Then, hold the quick release lever in one hand, and the opposite small nut in the other, and rotate the lever a few times, until you start to feel resistance. Then close the quick release lever in an upward or rearward direction, and feel it gripping firmly. It should take a little effort from two or three fingers to close it firmly. If the lever closes too easily, re-open it, wind in the nut on the other side of the bike a little more, then try again. If it’s too hard to close the quick release, open it, loosen the nut a little, then try again. 

For a rear wheel: Hold the wheel on the ground, then lower the back of the bike onto the wheel. You’ll notice there are two lengths of chain in your way. Position the smallest gear sprocket beneath the uppermost of these two bits of chain. Let it slot into the chain as you guide the axle of the wheel into the dropouts. The lower part of the chain should remain at the bottom of all this, out of your way. On a disc-equipped bike, ensure the disc is lined up to slot into its caliper as you replace the wheel. This stage can be fiddly, so be patient, and don’t force anything. When the wheel is neatly back in place, close the quick release skewer. If the quick release lever closes too easily with too much difficulty, see the advice for front wheels above.

Give the wheel a spin to check all is OK. Test the brakes. You’re ready to ride!