How To Fix A Bicycle Puncture

Step 1: You will need

Step 2: What is a puncture?

A tyre is made up of an inner tube filled with air, and a tyre which wraps over the top of it.

A puncture occurs when an object pierces both the tyre and the inner tube, causing it to deflate. Sometimes you can repair the inner tube using a puncture repair kit, sometimes it needs replacing altogether.

Step 3: Release the brakes and remove the wheel

Take off the brakes. Modern bikes have a quick release system. Squeeze and lift. If you have an older bike you may need an allen key to undo them. Turn the bike upside down and remove the wheel. Different wheels have different release mechanisms - usually a nut that needs unscrewing - or a quick release lever.

Step 4: Let out air

Then undo the valve cap and if there is one, the threaded metal collar.. Let all the air out of the tyre, by pushing the valve back towards the rim.

Step 5: Unhook the tyre

Insert a tyre lever under the rim and attach this to a spoke on the wheel. This will bring one section of the tyre out over the rim.
Now insert another lever a few centimetres away from the first. Be careful not to pinch the inner tube. Now gently slide the lever round the rim until one side of the tyre is released.
With the tyre still on one side of the rim, grasp the inner tube at the valve hole, push the valve up through the rim and pull it out of the tyre.

Step 6: Find the hole

To find the hole, first pump some air into the inner tube. You can either listen for a hiss, feel for airflow or place the tube in a bowl of water. We recommend this as you can see where the hole is from where the bubbles come out.

Step 7: Prepare

Now you know where the hole is, dry if wet, and sand down with the sandpaper from the puncture repair kit. Then apply enough rubber solution to fully cover the area where the patch will go. Blow on the solution for a few seconds until dry

Step 8: Repair

Place the patch over the dried rubber solution, and apply pressure until it is sealed tight. Grate some chalk using the grater on the back of the repair kit and liberally spread over the patch. This will soak up any extra glue and stop it sticking to the inside of the tyre.

Step 9: Replace the inner tube

Before you start, give the inner tube 2 or 3 pumps of air. This will stop it getting pinched when you put it back on the tyre.

Starting with the valve hole, put the inner tube onto the rim, under the tyre. Ease it on all the way round the wheel. Then hook the tyre back on with your hands. Make sure you don't pinch the inner tube if you're having trouble with the last section of tyre, use a tyre lever to get it back on.

Step 10: Pump up the tyre

Step 11: Put the wheel back on

Make sure the handle-bar is at right angles to the frame - so the wheel goes in straight. Then lower the wheel so that there's an equal space on either side of the wheel nuts. Then tighten.

Step 12: Reattach the brakes

Reattach your brakes. On a modern bike, hook the brake cable back. On an older bike, screw back with an allen key. Test them.

And off you go