What You Need Before You Start

Changing a bike tire requires a few specific tools, most of which are inexpensive and worth keeping in a small repair kit. You will need tire levers (usually two plastic or metal tools that pry the tire off the rim), a new inner tube or a patch kit if you are repairing the existing one, and a pump. Some people also carry a spoke wrench and a small adjustable wrench, though these are less essential for a basic tire change.

Before you begin, identify what type of valve your bike uses. Most modern bikes have either a Schrader valve (looks like a car tire valve) or a Presta valve (thinner, with a small locking nut at the top). Your pump and patch kit must match your valve type, so check this now rather than discovering the mismatch on the side of the road.

If your tire is flat, you also need to know whether you are dealing with a puncture you can patch or a tire that is damaged beyond repair. Small punctures in the inner tube can be patched; large tears, sidewall damage, or repeated flats in the same spot usually mean you need a new tube.

Key Takeaways

  • Remove the wheel by opening the quick-release lever or unscrewing the axle nuts, depending on your bike model.
  • Use tire levers to pry one side of the tire off the rim, then pull out the old or damaged inner tube completely.
  • Inspect the inside of the tire for thorns, glass, or sharp objects before installing a new tube.
  • Seat the new tube inside the tire, starting at the valve, then use your hands and tire levers to work the tire bead back onto the rim.
  • Inflate the tire to the pressure listed on the tire sidewall, checking that the bead is seated evenly all the way around.

Removing the Wheel From Your Bike

The first step is to get the wheel off the frame. Most bikes use one of two systems: a quick-release lever or bolt-on axles. Quick-release wheels have a lever on one side of the hub; open the lever fully, then unscrew the nut on the opposite side by hand until the wheel lifts free. Bolt-on wheels require you to unscrew the axle nuts with a wrench, usually a 15mm or 17mm size.

For the rear wheel, you will also need to move the derailleur (the mechanism that shifts gears) out of the way. Shift to the smallest cog, then pull the derailleur back and lift the chain off the smallest cog. The wheel should now slide out of the chain and frame.

Once the wheel is off, set it on a clean surface. If the tire is completely flat, you can work on it as is. If there is still air in it, you can deflate it fully by opening the valve or pressing the center of a Schrader valve.

Removing the Old or Damaged Tube

Insert a tire lever under the tire bead (the edge of the tire that sits on the rim) about six inches away from the valve. Pry gently until one side of the tire lifts off the rim. You do not need to remove the entire tire, just enough to access the tube. Once you have one section loose, slide the tire lever around the rim to free the rest of that side.

Reach in and pull the old tube out completely, starting at the valve. If the valve is threaded into the rim, unscrew it first. Once the tube is out, set it aside—you will inspect it later if you plan to patch it rather than replace it.

Before you install a new tube, run your fingers carefully along the inside of the tire, feeling for thorns, glass shards, or sharp objects. Even a tiny piece of debris will puncture a new tube immediately. If you find something, remove it with tweezers or a small tool. Also check the rim tape (the strip covering the spoke holes) to make sure it is intact and not torn.

Installing the New Inner Tube

Inflate the new tube just enough so it holds its shape—about 20 to 30 percent full. This makes it easier to seat inside the tire without twisting or pinching. Insert the valve through the rim hole first, then tuck the rest of the tube evenly inside the tire all the way around.

Now you need to work the tire bead back onto the rim. Start opposite the valve and use your hands to roll the tire onto the rim, working your way around in both directions toward the valve. The last section, near the valve, will be tight. Use tire levers if necessary, but work slowly and carefully—if you pinch the new tube, you will have to start over.

As you seat the tire, check that the bead is sitting evenly on the rim. Look at the line molded into the tire sidewall; it should be the same distance from the rim all the way around. If one section is higher or lower, deflate slightly, adjust that section, and re-inflate.

Inflating and Checking Your Work

Once the tire is fully seated on the rim, inflate it to the pressure printed on the tire sidewall. This is usually between 40 and 100 psi depending on the tire width and type. Use a pump with a gauge so you can see the pressure as you inflate. Stop at the recommended pressure—overinflating can damage the tire or cause it to burst.

After inflation, spin the wheel and watch the tire as it rotates. The bead should stay in the same position relative to the rim. If it bulges or shifts, deflate, reseat that section, and try again. Also check that the valve is straight and not bent or twisted.

Once you are satisfied with the tire, reinstall the wheel on the bike. For quick-release wheels, thread the nut hand-tight on the opposite side, then close the lever firmly. For bolt-on wheels, screw the axle nuts back in with a wrench, tightening them evenly so the wheel sits centered in the frame.

What to Do If You Are Patching Instead of Replacing

If you have a small puncture and want to patch the old tube rather than replace it, you can do so while the wheel is off. Inflate the tube fully and listen or feel for escaping air to locate the hole. Once you find it, dry the area completely and lightly sand it with the fine sandpaper included in most patch kits.

Apply the adhesive (if your kit requires it) and wait the time specified on the kit instructions—usually 30 seconds to a minute. Press the patch firmly onto the hole and hold it for the time listed, usually one to three minutes. Let the patch cure fully before reinstalling the tube, which may take several minutes.

Patch kits work best on small holes in the tube body, not on the valve or on the sidewall of the tire itself. If the damage is near the valve or if the tube has multiple punctures, replacement is more reliable than patching.

Frequently Asked Questions

How do I know which size inner tube to buy?

The size is printed on the tire sidewall in a format like "700x25c" or "26x2.0". This tells you the wheel diameter and tire width. When you buy a replacement tube, match both numbers. Tubes come in ranges (for example, one tube might fit 700x18-25c), so a single tube can work across a small range of sizes.

What if the tire lever breaks or I do not have one?

Tire levers are inexpensive and worth carrying. If you do not have one in an emergency, a flat-head screwdriver or the edge of a coin can work, though they are less effective and risk damaging the rim. Avoid using sharp metal tools that could cut the tire or tube.

Can I ride on a patched tube, or do I need to replace it?

A properly patched tube is safe to ride on. However, if the same tube gets a second puncture, replacement is more reliable than patching again. Tubes with multiple patches or damage near the valve should be replaced rather than repaired.

Why does my new tire keep going flat?

The most common cause is debris still inside the tire. Run your fingers around the inside again, checking carefully for thorns or glass. The second most common cause is a pinched tube during installation. If the bead is not seated evenly, it can pinch the tube against the rim. Reseat the tire and check the bead alignment before inflating fully.

Do I need to replace the tire itself, or just the inner tube?

The tire (the rubber part you see) and the inner tube (the air-holding part inside) are separate. Most flats are inner tube problems, not tire problems. Replace only the tube unless the tire has visible damage like cuts, bulges, or repeated punctures in the same spot.