How to Fix a Flat Tire on a Bicycle

How to Fix a Flat Tire on a Bicycle

Keeping your bike tires properly inflated not only makes for a more efficient ride but also can help you avoid things like the dreaded pinch flat, which happens when an underinflated tire bumps against a curb or rock and squeezes the inner tube against the metal wheel rim, puncturing the tube. But, even with perfect inflation, if you're a bike rider, you'll almost certainly have to fix a flat, either in your garage after a period of disuse or on the side of the road during a ride. Luckily, if you have the right tools, repairing a flat is easy. Without the right tools, it's impossible. Whenever you ride, make sure you carry with you a flat kit including tire levers (also called spoons), a patch kit and new inner tube, and either a pump or a CO2 cartridge with a nozzle matching your valve type (either Presta or Schrader) designed for refilling bike tires.

1 Release the brakes. The pads of most bike brakes sit close to the rim so the tire won't slip through. A small, quick-release lever allows the brake pads to expand to the sides so the tire can be removed. Flip the quick release. Some newer bikes, especially mountain bikes, may be fitted with hydraulic disc brakes. These work just like your car's brakes, and require some modelspecific finagling to release when changing the tire. If you have disc brakes, make sure you know what tool you need to release them, and keep it in your kit.

2 Remove the wheel. A bike tire is held to the fork or frame by a nut or quick-release lever that clamps onto an end of the axle. If you have a front flat, removing the wheel should be as easy as loosening the lever or nut by hand and pulling off the tire (some bikes have an additional mechanism to guard against tire loss even with the lever or nut loosened). If you have a back tire flat, you'll have to pop the chain free first. Shift the bike so the chain runs along the smallest back-wheel cog. Then flip the bike over, release the axle lever or nut, and push in the bike's derailleur with one hand to make the chain go slack while you lift the wheel free with the other.

How to Fix a Flat Tire on a Bicycle

3 Diagnose the problem. Why did your tire go flat? If you fail to find the problem, there's a good chance that something like a thorn stuck in the tire will make a new inner tube go flat, too. Inspect the outside of the tire for punctures, tears, or excessive wear. If you find a thorn, nail, or piece of glass, remove it.

How to Fix a Flat Tire on a Bicycle

4 Remove the tire. Let all remaining air out of the inner tube and attempt to slip the tire free of the rim by hand. If that doesn't work, reach for the tire levers or spoons. Start on a section of tire opposite the valve. Use the long end of the tire lever to pry underneath the tire bead and then pop it to the outside of the wheel rim. If unseating the tire with one lever doesn't allow you to pull the tire off by hand, work in a second lever near the first and pop a longer section of tire free of the rim. Eventually, you should be able to release all of one side of the tire bead. You needn't remove the tire completely from the wheel—just one full edge of the tire so that you can access the inner tube.

How to Fix a Flat Tire on a Bicycle

5 Remove the inner tube. Slide the valve out through the hole in the rim, being careful not to damage the valve with the rim. Then pull the entire inner tube out without damaging it further.

How to Fix a Flat Tire on a Bicycle

6 Inspect the inner tube. If there is an obvious gash or other catastrophic tube failure, you'll need to replace the inner tube. If there's a small puncture you can simply patch it, but these punctures can be hard to spot. If you're at home, submerge the tube in a bathtub or bucket of water and look for bubbles. If you're on the side of the road, run the tube close to your face—look, listen, and feel for escaping air. If you still can't find the puncture, you can try running water from a water bottle along the inner tube—air from the puncture will bubble in the water, making it visible. When you find the puncture, lay the tube against the wheel and explore for matched damage in the tire itself—sometimes the source of a puncture will still be embedded.

How to Fix a Flat Tire on a Bicycle

7 Patch the inner tube. Inner tubes aren't that expensive, so if you have a spare, it's worth simply replacing the tube (see Step 8). If you choose to patch it, follow the patch manufacturer's instructions. Typically, after cleaning and drying the area around a puncture, you'll rough up the surface to help the glue grab, apply the glue, and then apply the patch. If you choose to replace the tube, double-check that your replacement is the right size for your wheel (match the tube specs listed on the box to the wheel specs listed on the rim).

How to Fix a Flat Tire on a Bicycle

8 Replace the inner tube. With the new tube slightly inflated, reinsert the valve into the hole in the rim. Gently press the inner tube along the rim inside the tire, being careful not to twist the tube or otherwise compromise the path of the tire.

How to Fix a Flat Tire on a Bicycle

9 Reseat the tire bead. This is the trickiest part, during which a mistake can result in a pinched tube and another chance to practice your tube replacement. Start near the valve and reseat the bead by hand, pressing it into the rim first in one direction and then the other. The more tire bead you seat, the harder it will get, until you're left with a short section of tire opposite the valve that (likely) requires levers to reseat. If possible, use one lever to get the remaining tire back into the rim. If your tire is especially tight, you may need two levers—one to keep the tire bead from slipping off the rim and another to pop in a further section.

How to Fix a Flat Tire on a Bicycle

10 Once you've seated the tire bead, double-check that it doesn't pinch the tube. Then use your pump or CO2 canister to inflate the tube to the proper psi (listed on the bike tire).

How to Fix a Flat Tire on a Bicycle

The modern bicycle has taken many forms since its debut in 1817—from the Velocipede, or "Boneshaker" (the first model with pedals on the front wheel)—to the Penny Farthing, with its enormous front wheel and tiny back wheel.

YOU MAY ALSO LIKE