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How To Fix A Flat Tire

Don't Panic - We Can Help!

If you ride your bike then sooner or later, you'll get a flat tire. When this happens, we want to help you be prepared. As long as you carry a few basic tools, flat tire repair is easy -- even fun! Watch our video tutorial, read more about what you'll need and the steps to take, and sign up for our free maintenance clinic for hands-on experience.

Here's what you'll need:

  • A CO2 or hand pump - to be carried on your bike or in a pack 
  • A spare tube in the correct size -  to replace the popped one 
  • Tire levers - to make removing your tire easier

Step 1: Open The Brakes

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.

Step 2: 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, 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.

Step 3: Remove The Tire and Tube

Remove the valve cap and nut.

For Presta valves, unscrew the tip and press down to let all the air out.
For Schrader, 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 here. Continue with your third lever until you can get one side of the tire off. Then reach inside and extract the tube. Pull the other side of the tire off the rim or pry it off with your levers.

Step 4: Inspect The Tire

It's important to find whatever caused the flat and remove it. If you don't, the sharp item might still be in the tire where it'll just pop your new tube. To find it, remove your glove (or use a rag), and run it around inside the tire in both directions. If something sharp is still stuck in your tire, it'll snag the glove. Remove the nasty. If you can't find anything, it's likely it got knocked out during the disassembly procedure.

Step 5: Install The Tire and Tube

1. Inflate the new tube just enough to round it out and remove any wrinkles, and place it inside the tire. Stand the wheel up (rest it against your shins) with the valve hole on top and hold the tire/tube over the wheel so that the valve is on top.

2. Place the valve partway into the hole and simultaneously push the part of the tire edge (called the "bead") that's at the valve and closest to your legs onto the rim. With both hands moving downward away from the valve, finish working the bottom tire bead (the one closest to your legs) onto the wheel all the way around. If it won't fit onto the rim, check that the valve is inside the tire, not trapped beneath the bead.

3. With one bead in place, tuck the tube fully inside the tire and on top of the rim, which will cause the other bead to rest flush against the rim. Work this bead on starting at the valve as you did with the first. You may have to push the valve into the tire to provide clearance for the bead. Once you've got it started, work your hands away from the valve pressing the bead onto the rim around the wheel.

4. With a few inches of bead left to pop onto the rim, the tire will resist. Let all the air out. Crouch and rest the wheel on your knee to have something to push against. Now, hold the bead in place with one hand and with your stronger hand, push down to roll the stubborn section onto the rim with the heel of your hand (main photo). But don't try to pop it on all at once. Install an inch at a time, moving your hand along until you've fully installed the tire. Got it? Good job!!

Step 6: Inflate And 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 you're pushing against your hand, not the valve. Inflate the tire until it's just firm (not fully inflated). At this point, inspect the tire to make sure it's "seated," which means that it's sitting correctly on the rim.

If the tube gets trapped beneath a bead, inflating further may blow the tire and tube off the rim! There's a bead line on the side of the tire that should be equidistant from the rim all the way around on both sides of the tire. If it's not, or if you see a section of tube peeking out from under the rim, let the air out, work the tube back into place, reinflate partway and check the tire again. When it's seated correctly, inflate it fully. Install the valve nut (if your tube uses one) and cap finger tight (overtightening the valve nut can damage the tube and make it difficult to loosen it when you need to fix a flat). Reinstall the wheel in the frame, close the brake quick release or reattach the noodle or cable and you're ready to ride!