How to Fix a Flat Tire

Sooner or later, you'll ride over some glass or perhaps hit a rut or hole and get a flat tire. As long as you carry a few basic tools, flat repair is easy -- even fun! Always be safe and work off the road/trail so something doesn't flatten you. Here's how it's done:

First, gather your tools: Tire Levers to help you remove the tire, tubes (we suggest you carry 2 on every ride and either a hand pump or CO2.

Tools to Fix a flat tire

Step 1: Open the brake

As soon as you get that "sinking" feeling or hear the hiss of escaping air, let your ride partners know you have a flat (so they won't disappear over the horizon) and stop. If it's a rear flat, shift onto the smallest rear cog. The first step in wheel removal is opening the brake, which makes it easier to get the wheel out.

You will first need to release your brake caliper in order to remove the wheel. Most Road Bikes are equipped with side pull brakes while Mountain Bikes and Hybrids typically have a linear pull system. If you have disk brakes this step is unnecessary.

lift the breaks

A. For side pull brakes simply rotate the side pull lever so that it is pointing out.

B. For linear pull brakes lift the end of the “noodle” out of the holder.

Step2: Remove the wheel:

Open the quick release (or loosen the axle nuts) on the wheel with the flat and lift the bike to remove the wheel. To extract rear wheels, it helps to pull the derailleur back slightly to clear the axle parts as the wheel passes through. For fronts, you'll probably need to hold one side of the quick release and turn the other counterclockwise to create clearance to get past the wheel-retention tabs on the fork.

Never force the wheel out! If it's stuck, determine what's holding it in place and free it. Lay the bike on its left side so you don't damage the derailleur or get dirt in the drivetrain.

Step 3: Remove the Tire & Tube

Remove the valve cap and nut (sometimes found on Presta valves. For Presta valves, unscrew the tip and press down to let all the air out. For Schraders, poke the end of your tire lever into the valve to release all the air. Starting directly opposite the valve, wiggle a tire lever beneath the tire's edge and pry down to lift. If possible, hook the lever on a spoke (many levers are made to do this), or hold it in place. Place another lever about 6 inches away from the first and pry. Continue with your third lever until you can get one side of the tire off. Then reach inside and extract the tube.

If you have trouble getting the tire off, make sure all the air is out of it. Even a little air can make the tire a lot tighter. Some cyclists prefer to remove only one side of the tire to ease reinstallation. The disadvantage is that it's harder to check inside the tire to find whatever popped the tube.

Step 4: Inspect the Tire

It's important to find whatever caused the flat and remove it. If  sharp item(s) remain in the tire it'll just pop your new tube. To find it, use your glove (or use a rag), and run it around inside the tire in both directions. Any sharp debris will snag the glove/rag. If you can't find anything, it's likely it got knocked out during the disassembly procedure.

Be sure to check inside the rim, too. The rim strip covering the sharp spoke holes (and sometimes the spoke nipples), can move, which allows the tube to be cut. Make sure that the rim strip covers completely. As long as the hole in the tire is about 1/4-inch long or less, you'll be okay reusing it. If the tire has a large gash in it, you'll need to patch it somehow before reinstallation. Paper money works great. Simply place it over the hole as you install the tire and tube. It'll reinforce the tire at the hole and get you home. Replace the tire ASAP.

Step 5: Install the Tube & Tire

Inflate the new tube just enough to give it shape and place it inside the tire. Stand the wheel up and rest it against your shins with the valve hole on top and hold the tire and tube over the wheel so that the valve is on top.

Place the valve partially in the hole while pushing the tire edge (called the “bead”) onto the rim. Work your way down away from the valve, making sure that the tube stays inside the tire and is not trapped beneath the bead. Repeat this process for the opposite side of the tire.

With a few inches of bead left to work onto the rim, the tire will resist so let all the air out. Now hold the bead in place with one hand, while working the remaining section onto the rim with your other hand an inch at a time.

Make sure that your spare tube's valve is the right type for your wheel. Tubes that are slightly narrower than the tire fit fine and are easiest to install (for example: a 700 x 20c tube in a 25c tire and a 1.5-inch tube in a 1.9-inch tire). A trick to create slack and ease tire installation is to go around the rim squeezing the tire beads into the rim's center (the deepest portion). If you locate the tire label at the valve, you'll have a reference point when searching the tire for what popped the tube.

Step 6: Inflate & Seat the Tire

Place your pump on the valve and inflate the tire. To prevent valve damage brace it by wrapping a finger behind a spoke, so that you’re pushing against your hand and not the valve. Inflate the tire until it is just firm and check to make sure it is “seated” properly on the rim.

If the bead line on the side of the tire is equally distant from the rim all the way around on both sides, inflate fully and install the valve nut (on presta valves), Remember that over tightening can damage the tube and make it difficult to loosen later. Reinstall the wheel in the frame, close the brake quick release or reattach the “noodle” or cable and just like that IT’S TIME TO RIDE!

Not all portable pumps have the power to fully inflate all tires. But that's okay. You only need enough air to make the tire firm enough to ride on. If you can't get it hard enough to finish your ride, find a bike shop or head home to fix it properly. The first time you fix a flat it may take 30 minutes to an hour. But, with practice, you'll get much faster. Experienced cyclists can easily repair one in 10 minutes. If you ride regularly and haven't fixed a flat yet, practice at home to build your confidence.