How To Fix A Flat Bike Tyre

Hello, my name's John from On Your Bike in London. I've been a bike mechanic for 12 years. I'm going to show you a few things about bikes, things like setting it up, selecting the correct size, and a few maintenance tips as well.

How to fix a flat tire. When you've got a puncture, what you need to do is remove the wheel and change the tube that you find inside the tire. This one's got nuts holding the wheel on, so you use a spanner, in this case, this one's a 15.

You might have a bike that has a quick release, a lever that you just pull down. I'll show you one of those after. Just undo these and the wheel will come out.

And if you get some tire lever and just hook them underneath the tire, gently go around the wheel taking the tire out of the rim. Once you get about ¼ way around, you'll find that you can then just run the tire lever around the wheel and it will release the tire. Make sure you use plastic levers, because if you have aluminum rims which most bikes have these days, that you'll find they'll mark or they score the rims.

Once the side of the tire is out, you can pull the inner tube out, gently pull and then lastly, the valve which just pulls out of the valve hole. I've been down to the shop and I bought a new tube which we are going to reinstall into here. What we need to do is put some air into it, get some shape into the tube.

Just push that into there and then gently pump up, get some shape. And then start off with the valve hole by putting that through there. It goes through the rim and then if I lay the wheel on the floor, it makes it a bit easier, and then just thread the tube into the top.

If you find that it is too big, you might need to let a little bit of air out of the valve. Not too bad. And then what you gradually do, start with the valve hole, and then slowly put the tire back on its rim.

Tire pressure will be marked on the side of the tire. This one is 55 psi, which is marked on the side. Just locate that back into the bike.

Not going to do it too tight because I'm going to connect the brakes just to make sure they are levelled. Reconnect those. Make sure the brakes work. .