How to fix a bike flat
by Will Dean
So you’re riding along, minding your own business, maybe humming a tune, and suddenly every push of the pedal takes ages, and people are walking past you. Unless you have some kind of heart condition (in which case, please seek medical attention), your tire probably popped a flat. Don’t fret, though: Flats are quick and easy to fix with the right tools.
- First, you’re going to have to remove your wheel from the bike. If your bike is newer, it should have quick release wheels. These have a lever on one side and a cap (a little cone-thingy) on the other. Flip the lever, which should take some effort, and turn it until the wheel is loose. The wheel should be easy to take off. If you have an older bike, the wheel might be attached by nuts. You should carry around an appropriately-sized wrench if this is the case, or an adjustable one. Use the wrench to take the nuts off, put them somewhere safe and take the wheel off.
- Next, you need to remove the tire. You can do this with your hands, or use a tire tool (they come in sets of two) and wedge it between the rim and tire. Lever it up and push the tire away from the rim. Leave the first tool there and use the other one in the same way a few inches away. Continue doing this around the tire, pushing the tire away from the rim while leaving the original tool in
place. You can also use your hands and work the tire off the rim, but it’s harder.
- Remove the tube from inside the tire, but use the valve as a marker so you know where the tube was (so you can find anything lodged in the tire that might have caused the flat). Look at the tube to see if there are any obvious punctures or bits of metal protruding.
- Fill the tube with air and listen for a hiss of air escaping. Feel along the entire length to detect any air coming out. Once you’ve found the hole, let the rest of the air out of the tube.
- Scuff up the rubber around the puncture with the little piece of sandpaper or rough metal in the patch kit. Apply the glue to a space bigger than the patch you’re going to use. Each kit comes with a few different sizes, and if your puncture is small, you can cut up patches to make them last longer. The most important point is to make sure the hole is entirely covered.
- Once the glue is dry, press the patch onto the glue and hold it there for a few minutes. Use a book, or something heavy and flat, to apply even pressure. While you’re waiting, check the tire for anything (metal, glass, rock, etc.) that could have caused the flat. Look especially hard around the part of the tire that corresponds to the puncture on the tube.
- Put the tube back in the tire and pump it up to test for leaks. Let the air back out and put the tire back on the rim, and make sure that the tube isn’t pinched between the tire and rim. Use your hands to put the edges of the tire inside and use the tire tool (if you have to) to put the last sections on by wedging the tire tools against the rim and lifting the tire onto the rim.
- Put the wheel back on the bike and reattach it. With quick release tires, don’t just spin the lever until it’s tight; spin it until it’s just starting to get tight and then push the lever over until the opposite side is showing. It should be easy until the lever is perpendicular to the bike; then it gets progressively harder. Some quick releases become easy to push after they are most of the way over, so don’t worry if it’s really hard, then gets really easy. If you’re using nuts, tighten one side part of the way, then the other, and alternate until they are both snug and the wheel is evenly situated on the frame (i.e. no tilting to either side).
- Make sure the brakes are not rubbing against the wheel, then pump up the tire to the recommended pressure, which should be listed on the sidewall of the tire.