How to Repair a Cycling Puncture
If you ride a bicycle enough, getting a flat tire is one of those inevitable events. It’s a good idea to know how to fix a puncture before you get one, since flats often happen in places where you don’t want to spend a lot of time fiddling around with your tire. Ideally, you’ll be able to fix your wheel quickly and keep moving. We’d recommend practicing removing your wheel and tube in advance so when you finally do have to fix that flat, it won’t be the first time you’ve tried to do this.
First, a little terminology is necessary. Your tire is the thick textured rubber ring that actually touches the road. It protects your tube, which is an inflated donut-like tube inside the tire. Your wheel is the metal frame that the tube and tire attach to, and the side of the wheel is known as the rim. When you get a flat tire, it’s because your tube has deflated, usually from a puncture in the tire, although you can also get a flat from things like hitting a pothole or your spokes coming into contact with the tube because the protective tape has cracked or shifted.
To fix a flat, you’ll need a few key pieces of equipment. If you ride your bicycle a lot, we highly recommend that you keep all of the following in a small bag attached to your bike or in your backpack every time you ride – you never know when you’ll have to use them! First of all, you’ll need a set of tire levers, which are plastic levers that hook under your rim and let you pop the tire off of the wheel. You can get these for less than two dollars at any bicycle shop. You’ll also need a patch kit, which includes little rubber patches, glue, and a piece of sandpaper or a file, or a new bicycle tube. Patch kit can be picked up for five to ten dollars at bicycle stores as well, with new tubes running slightly more than that. Make sure you’re buying the right sized tube for your bicycle. Finally, you’ll need a bicycle pump. You can purchase a lightweight hand pump to bring with you on your rides; they take longer to fill your tire than a bigger foot pump, but can be a real life-saver. Either way, make sure that your pump is suited to the type of valve on your tube. There are two main valve types: Schrader and Presta valves. Bicycle pumps often come with adapters so that you can use the pump on either valve type. Alternatively, you can purchase pressured air canisters that will fill your tube up almost instantly. These are a more expensive option, and can only be used once, but many avid bicyclists swear by them. Finally, know if you have ‘goo’ in your tube. Some tubes come with a slimy green substance that’s designed to plug small holes temporarily. This won’t change the way you fix your punctured tube, but be forewarned that it can get messy.
If you think you have a flat, stop riding immediately. Even if you think there’s some air left in the tire, you can do serious damage to your wheel by riding on a flat. A new wheel costs a whole lot more than a new bicycle tube, so don’t risk it. Remove the wheel from your bicycle (very experienced riders can fix a puncture without doing this, but for most of us it’s faster and easier to fix a flat tire with the wheel detached from the bike). If it’s your front tire, you’ll just need to loosen the quick-release lever or the nuts securing the wheel to the frame, and probably to release your brakes so the tire can easily move between the brake pads (don’t force it!). If it’s your back tire, you’ll have to remove the wheel from the chain. Take a good look at how your chain runs through the cassette on your back wheel and through the derailer below it, so you can put the wheel and chain back on properly when you’re done. Again, make sure you’ve released the quick-release lever or nuts, and your brakes. Let all of the air out of the tube.
Use your tire levers to get the tire off of the wheel, using the lever to pop the wheel off and then working full around the wheel. Do the same on the other side of the wheel. With the tire off, you’ll see the tube inside. You can try inflating it to see where air leaks out. Don’t worry about overinflating it – the tube can take a little extra air and this makes it easier to find the leak. You can also hold the tire in your hands, and check it carefully from the inside and outside for punctures. Make sure that no object is still lodged anywhere. Also, visually check your tube. Once you’ve figured out where the puncture is, you can decide how to fix it.
If you can’t find a puncture hole in your tire, check the tire for places where it’s worn through. If this is the case, you’ll need a new tire or you’ll just get another flat. You should also check the inside of your wheel where the tube sits; if the tape that protects the spokes from poking the tube has worn, cracked, or shifted, that could be the cause of the problem. In a pinch, you can improvise rim tape with a dollar bill. It’s a good idea to replace the tape properly as soon as you get a chance since rim tape costs just a few dollars and is easy to find at your local bike shop.
If it’s just a small hole, you can patch it. Deflate the tube once again. Use the file or sandpaper in your patch kit to roughen up the area around the hole; this helps the glue to stick. Apply a good amount of glue around the puncture hole, and let it dry for five minutes or as directed on the tube. Don’t stick the patch on immediately – the glue needs to set for a bit. Next, stick the patch down on the glue and press very firmly and hold down, applying pressure, for about a minute. Peel the plastic backing off the patch. Now put the tube back in the tire and use your levers to put the tire back onto the wheel, making sure you line up the valve with the hole in the wheel. Re-inflate the tire and put it back onto your bike, making sure that it’s facing the right direction and that you’ve reattached your brakes and set up your chain properly. You’re ready to go! A properly applied patch can last forever, and you can patch a tube quite a few times.
If you want to replace your tube due to a very large puncture or the valve tearing away from the tube, you can just install a new tube and put the wheel, tube, and tire back together as described above. Happy riding!