How To Change A Flat Tire On Your Bike

How To: Gather what you need for the repair:

1. Appropriately sized tube or patch kit.
2. Wrench to remove your wheel (unless your wheel has a quick release).
3. A set of two tire levers.
4. Air pump.
5. Air pressure gauge.

Depending on your bike's setup, you may not need all of these tools.

How To: Remove the wheel with the flat tire. The front tire is usually the easy one to remove. If it's a quick release, simply lift up the quick release lever and give it a few turns until the wheel is loose enough to remove. If your wheel has bolts, then just unthread them with the appropriate wrench (usually 15mm).

How To: The chain is on your rear wheel, and if you have gears this can be a little intimidating. First shift the chain so that it is on the smallest rear cog. This will make reinstalling the rear wheel a lot easier. To remove the wheel, simply loosen your bolts or quick release. Once the wheel is free, remove it from the dropouts. Lift the chain off the cog and let's get to fixing that flat!

How To: It's a good idea to do a quick eyeball of the outside of the tire. The goal is to figure out why the tire went flat. Is there an obvious screw or piece of glass stuck into the tire? Once you've finished your inspection, we'll need to work on removing the tire from the rim.

How To: For removing and installing tires, it helps to understand what's going on in there and how a tire works. We're going to assume that like most bikes, yours has a traditional clincher type rim and tire. If you're running a sew-up or tubeless setup, we'll assume you know how to change a flat and we won't cover those types of setups here. On the edge of a normal "clincher" rim, there is a little lip that runs the whole way around on both sides. On the edge of the tire, you'll find the tire's "bead."

When you inflate a tube, it stretches and expands to push the tire's bead under the rim's lip. This creates a lock between the tire and tube. The more pressure you put in the tube, the harder it presses the bead under the lip. In this way, some tires can hold more than 100 pounds of pressure without blowing off the rim.

How To: Make sure that all of the air is out your tires. Some bike tires are easy to remove. You can pop them off with your thumbs. Others have a tight fit and will be more of challenge. If your tire proves difficult to remove, you may need a pair of tire levers. These are inexpensive and can save your fingers a lot of prying and pain. Don't use a screwdriver or anything sharp. You risk damaging the tire, and later on in this process you'll risk ruining your new tube. The butt end of a spoon or butter knife is a good substitute in a pinch.

How To: You may have already taken off your tire by now. But if you haven't, and you need some help, here is how to use a pair of tire levers. Insert one of the tire levers under the bead of the tire and pry it so that you can hook your tire lever to a spoke. Now that both your hands are free, use your other tire lever to do the same thing a few inches away from where you left your first lever. You should now have popped the bead over the edge of the rim. From here, you should be able to slide the tire lever around the rim while under the tire. Your tire should come right off.

How To: If you haven't done so already, it's time to figure out why you got your flat. It'll be a real waste of time if you go through this whole process and then get another flat as soon as you pump up your new tube. Inspect the inside of the tire for glass or anything sharp that may have poked through the tire. Use a rag to wipe the inside of the tire and search for any tiny pieces of glass or thorns that may be imbedded into the tread.

How To: Also inspect the inside of the rim. The rim strip that protects the tube from spokes often moves or stops functioning. If all of this still hasn't helped you figure out why you got a flat, you may want to inflate the old tube to see if you can match up its puncture to where it happened on the tire. You may also want to inflate the old tube to see the size of the hole. If it's a small one, it may be a candidate for a patch.

How To: Patching a tube is not for everyone. It's inexpensive and easy to do. But if you're impatient while doing it, the patch can easily fail and leave you flat again. It is a simple process, though, and we will walk you through it. First, you need to inflate the old tube and find the hole. Hopefully, this is easy. But for tiny holes, you may have to hold the tube underwater in a sink to find the air bubbles escaping from the hole. Once you find the hole, be sure to hold your finger over it and squeeze the tube to find if there are any other leaks.

How To: Patches will work best on small holes. There are several kind of patches. Some are as simple as peeling off a sticker and placing it over the hole. For the old-fashioned rubber cement patch kits, here's what you do.

Rough up the area around the hole with some sandpaper (almost always include in bicycle patch kits). Clean the area and then put a thin coating of rubber cement glue around the hole. Make sure that the glue area is a bit bigger then your patch. Let the glue dry for a few minutes or until it's not gooey. Next, peel the backing off your patch and center if over the hole. Hold the patch firmly in place for at least a minute.

How To: If you are installing a new tube, the first thing you'll do is put a little air into it. Don't overdo it. Use just enough air so that the tube roughly holds its shape. This will help you install it into the tire without it twisting or getting into the wrong position. On a Presta tube, remove the little lock ring that is on the valve.

How To: Some tires have a directional tread pattern. So read your tire's sidewall to see if there is any indication that the tire should be put on one way or another. Put half of the tire's bead onto the rim so that half of it is on and half of it is off.

How To: Locate the valve stem on your tube and the valve stem hole on your rim. Insert the valve stem through the hole and begin inserting the tube into the tire.

How To: Working in both directions from the valve, ease the tube into the tire. Make sure that the tube is not twisted or doubled over at any point.

How To: Once the tube is completely inside the tire, you can begin working the tire's other bead on to the rim. Start pushing the bead of the tire into the rim at the valve stem and then work your way around. Sometimes this is easy. But if your tire starts to get tight, you may need to resort to your tire levers again. Hopefully you won't need them and you'll be able to work the bead onto the rim. But if tire levers are a necessity, pay extra close attention that you are not trapping the tube under the rim when you use the lever to pry. It's easy to puncture a tube in this way.

How To: Once both beads of the tire are on the rim, it's time for a quick inspection. Take a look around the edge of the rim on both sides to see if the tube is visible between the bead and the rim and any point. You'll need to "massage" the tube inside the tire if any of it is visible.

How To: Check that your valve is pointing toward the center of the hub and not crooked. If you have a Presta tube, you can install the little lock ring onto it now and thread it down toward the rim. Don't put this on too tightly. It's fine to leave it lightly finger-tightened until after you inflate the tire. On a Presta valve, you will also need to loosen the threaded valve so that you can put air into it.

How To: Let's air this baby up already! Some pumps will have a lever to lock the nozzle onto the valve. Others will thread onto the valve. It can be different from pump to pump, so you'll have to figure out how your pump works. To start, you want only 15 to 20 pounds of pressure. If you're pump doesn't have a gauge, keep one handy to check your progress.

How To: When your tire has 15 to 20 pounds of pressure, remove the pump from the valve. Spin the wheel and inspect it to see how the tire is seating. You especially want to watch for any bulges on the side of the tire that might indicate that the tube is underneath the bead. When this happens, the bead will not lock properly under the lip on the rim. Inflating the tire more will push the tire bead off the rim and you'll explode your new tube in a thunder crack of failure. Sometimes the tire is sitting funny, and a little massaging the bead into place is all it takes to get it seated evenly around the rim.

How To: When everything is seated properly, finish inflating the tire to the proper PSI. This will be listed on the tire's sidewall.

How To: If you have brakes, you may need to disconnect them or use the quick release to fit the tire back into the fork. If your brake is a caliper, look for a little lever like this. If you have V-brakes, just squeeze them together with one hand and remove the silver brake noodle so that the brakes can expand open.

How To: To reinstall your front wheel, place it into the dropouts and make sure the tire is centered between the fork legs.

How To: To reinstall a back wheel with no gears, put the chain onto the rear wheel's freewheel or cog. It's easiest to put the chain first onto the gear on the rear wheel, then route the chain on to the sprocket at the cranks. Keep the wheel centered in between the frame. Additionally you'll also need to keep the chain tensed as you tighten the wheel. Your chain should have 1/2-inch to 3/4-inch of vertical slack once your wheel is tightened into place. This can be hard to measure. Basically, you want the chain to have enough slack in it so that it runs smoothy over the sprockets without binding, yet won't fall off and derail.

To reinstall a back wheel with gears, push down on the bottom guide pulley of your rear derailleur. This will open a gap in the chain loop where you want to install the wheel. Slip the rear wheel into the opening in the chain loop you have created. Guide the chain onto the smallest cog (which is where you shifted the chain to earlier before you removed the rear wheel). Place the wheel into the dropouts of the frame.

How To: If your wheel has axle nuts, then tighten them snugly. You do not want your wheel to fall off, but you don't need to stand on the wrench either. Some fork dropouts will have lock washers or grooves that the axle nuts are meant to fit into. Look for this as you install the wheel. If you have a quick release on your wheel, this is where you need to be very careful. Improperly installed quick release wheels are one of the major lawsuits involving bicycles, not to mention an awful way to get hurt.

Once the wheel is seated in the dropouts, hold the lever in the open position and thread the knob on the other side until it is finger tight. Now flip the lever closed. It should be tight. The CSPS says, "lever should leave an imprint on the palm of your hand from the force required to close it." If the lever is not tight enough, open it again and tighten the knob on the other side. Then re-close the lever until it is properly tight. Check that your wheel is still centered and if everything looks good when spinning it. Don't forget to re-connect those brakes!