How to Repair a Puncture
Tuesday 23rd August 2016
There's little worse than realising you can't make it home because your tyre is punctured. Try and keep a puncture repair kit on you. Fixing a puncture is not a difficult task, but will require some time and a willingness to get your hands dirty.
1. Is it repairable?
See if you can locate the puncture before doing anything else. Turn the bike over, so it is resting on the handlebars and seat, and gently spin the tyre to look for embedded objects or obvious holes.
If there are many punctures, or the hole is quite large, it will probably be best to replace the tyre. If it is a small puncture, a repair should see it on the road again soon.
This is what you'll need. The larger object is a floor pump. The Giant Control Tower is used for inflating and deflating tyres. A mini-pump can also be used, it just takes longer.
2. Deflate and remove the tyre
Assuming it is repairable, take the air out of the tyre by releasing the valve. Once flat, take the tyre off the rim. This can be done easily with a tyre lever. Some people do this with a screwdriver, but this should never be done - it will cause more problem in the long-run! So this must be removed with some care. Pry the tyre lever between the tyre bead and the rim to loosen it enough until it pulls free on one side.
Again, carefully take the tube out of the tyre, being conscious of the valve stem - you don't want to rip this off.
3. Use water to find the puncture
The easiest way of locating the source of the puncture is by using a bowl or a bucket of water. Simply fill the tube with air, listening for the hiss of it escaping, and lower the tyre into the water. Bubbles should appear at the location of the puncture.
If there are multiple punctures, it may be easier to repair one a time, so you can check the effectiveness of your repairs in the water as you go.
4. Prepare the area for repair
Your patch kit should come with some sandpaper-like material with which you buff the area around the puncture. Now spread your glue thinly across the area, and let out as much air as possible. The glue should be spread across a bigger area than the patch.
5. Apply the patch
Peel the plastic backing from your patch and apply it to the prepared area. Press firmly, but avoid getting any glue on your fingers if you can.
Now the tyre should be repaired, so you can test it in the water if you feel the need or if you suspect more punctures. There will be some French chalk in your repair kit. This should be used on any excess glue to prevent it sticking on the inside of the tyre.
6. Re-attach the tube
If the tube is ready to roll, slide it back onto the tyre, ensuring the valve stem lines up with the hole in the rim.
7. Push the bead of the tyre over the rim
Placing the tyre back onto the rim is a fairly difficult part of the process. Avoid using a tyre lever for this part, as you want to avoid causing any more punctures. The aim it to push the bead of the tyre back over the rim without pinching it. Fixing one side of a tyre at a time is the most stress-free way of achieving this!
8. Check everything else is where it should be
Place the wheel back on the bike, and reconnect the brake if it was disconnected. Ensure your gear chain is still in place, and that the rim is centred between the brakes. Tighten down your nuts or quick release skewer and re-inflate the tyre through the valve.
Keep to the stated pressure that will be written on the side of the tyre - over-inflation will lead to more punctures.