Step 1 - Open the break

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 (photos), which makes it easier to get the wheel out.

Open sidepull brakes by fully rotating the little lever on the brake upwards (a)

Open linear-pulls (also called "V-brakes") by lifting the end of the "noodle" out of its holder (b)

Some sidepulls are opened by pressing a button on the lever. Look for this if there's no lever on the brake.

Open cantilever brakes (these feature a cable that runs over the top of the tyre) by lifting the cable end on one side out of its holder.

Tips

• Be safe! Work off the road/trail so a semi doesn't flatten you!
  
• While it's possible to get the flat tyre through the brake without opening it, it won't be so easy reinstalling the wheel when it's fully inflated. That's why we recommend opening the brake first.
  
• If you have disk brakes, there's nothing to open. The wheel will come right out of the brake with no muss, no fuss. Cool.

Step 2 - Remove the wheel

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 (main photo). 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 (inset photo).

Tips

• 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.

Remove the tyre and tube: Remove the valve cap and nut (sometimes found on Presta valves: inset photo). For Presta valves, unscrew the tip (inset photo) and press down to let all the air out. For Schraders, poke the end of your tyre lever into the valve to release all the air. Starting directly opposite the valve, wiggle a tyre lever beneath the tyre'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 (main photo). Continue with your third lever until you can get one side of the tyre off. Then reach inside and extract the tube. Pull the other side of the tyre off the rim or pry it off with your levers.

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

Inspect the tyre: It's important to find whatever caused the flat and remove it. If you don't, the sharp item might still be in the tyre where it'll just pop your new tube. To find it, remove your glove (or use a rag), and run it around inside the tyre in both directions (photo). If something sharp is still stuck in your tyre, 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.

Tips

• 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 tyre is about 1/4-inch long or less, you'll be okay reusing it.
  
• If the tyre 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 tyre and tube. It'll reinforce the tyre at the hole and get you home. Replace the tyre ASAP.

Install the tube & tyre: 4 Easy Steps

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

2. Place the valve partway into the hole and simultaneously push the part of the tyre 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 tyre 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 tyre, not trapped beneath the bead.

3. With one bead in place, tuck the tube fully inside the tyre 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 tyre 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 tyre 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 tyre. Got it? Good job!!

Tips

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

Inflate and seat the tyre: Place your pump on the valve and inflate the tyre. To prevent valve damage, brace it by wrapping a finger behind a spoke (photo above) so you're pushing against your hand, not the valve. Inflate the tyre until it's just firm (not fully inflated). At this point, inspect the tyre to make sure it's "seated," which means that it's sitting correctly on the rim.

If the tube gets trapped beneath a bead (photo top), inflating further may blow the tyre and tube off the rim! There's a bead line on the side of the tyre (photo bottom) that should be equidistant from the rim all the way around on both sides of the tyre. 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 tyre 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!

Tips

• Not all portable pumps have the power to fully inflate all tyres. But that's okay. You only need enough air to make the tyre 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.