Remove the wheel and old tube

Start by flipping your bike upside down so it rests on the handlebars and seat, or use a bike stand if you have one. This keeps the wheel accessible and stable while you work.

For the front wheel, open the quick-release lever (or unscrew the axle nuts if your bike has them) and lift the wheel out of the fork. For the rear wheel, shift to the smallest chainring first, then open the quick-release and pull the derailleur back to create slack in the chain. Lift the wheel up and out of the frame.

Once the wheel is off, use a tire lever — a flat plastic or metal tool — to pry one side of the tire away from the rim. Insert the lever under the tire bead (the edge that sits in the rim) and hook it to a spoke. Slide the lever around the rim to break the tire loose all the way around. You do not need to remove the tire completely, just loosen it enough to pull the old tube out.

Reach inside and pull out the old tube. Set it aside — you may need it later to figure out what size replacement to buy if you do not have the size written down.

Key Takeaways

  • Tube size is printed on the old tube or on the tire sidewall, and you must match it exactly or the new tube will not fit properly.
  • Before installing the new tube, check inside the tire for thorns, glass, or sharp debris that punctured the old one, or the new tube will fail the same way.
  • Inflate the new tube partially before seating it fully in the rim so it stays centered and does not twist.
  • The tire bead must seat evenly on both sides of the rim before you inflate to full pressure, or the tube can pinch and puncture.

Check the tire for what caused the puncture

Before you install a new tube, run your fingers carefully inside the tire to feel for thorns, glass shards, or sharp metal pieces. This is the most common reason a new tube fails when ready — the same object that punctured the first one is still embedded in the tire.

If you find something, remove it with tweezers or pliers. If the tire has a large cut or gash in the rubber itself (not just a small puncture hole), the tube will push through and fail. In that case, you need a new tire, not just a new tube. A patch kit can temporarily seal a small cut, but it is not a permanent fix.

Look at the rim tape — the strip of rubber or plastic that covers the spoke holes. If it is torn or missing, the spoke ends can puncture the tube. Replace the rim tape if it is damaged.

Get the right size replacement tube

Tube size is printed on the sidewall of your tire in a format like "700x25c" or "26x2.0". The first number is the wheel diameter, and the second is the tire width. You must buy a tube that matches both numbers, or it will not fit.

If the size is not visible on the tire, check the old tube — it is usually printed there. You can also take a photo of the tire and bring it to a bike shop, and they will tell you the size in seconds.

Tubes come in different valve types: Presta (narrow, with a small nut at the top) and Schrader (wider, like a car tire valve). Match the valve type of your old tube exactly. Some tubes work with both, but most are one or the other.

Install the new tube

Inflate the new tube partially — just enough so it holds its shape and is not completely flat. This prevents it from twisting or folding as you seat it in the tire.

Insert the valve through the rim hole first. Then work the tube around the inside of the tire, making sure it sits evenly and does not bunch up or cross over itself. The tube should form a smooth circle inside the tire with no twists.

Starting at the valve, use the tire lever to tuck the tire bead back into the rim. Work your way around the wheel, using the lever to pry the bead over the rim edge. As you get closer to finishing, the tire will become harder to push on — this is normal. The last section may require you to push the valve up into the rim to create slack, then pull the bead over.

Do not use the lever to force the last section. If it will not go, deflate the tube slightly, work the bead a bit more, then re-inflate. Forcing it can pinch the tube and cause an when ready puncture.

Seat the tire bead and check alignment

Before you inflate to full pressure, spin the wheel and look at the bead line — the edge where the tire meets the rim. It should be even on both sides of the rim all the way around. If one side is higher or lower than the other, the bead is not seated correctly.

If the bead is misaligned, deflate the tube completely, work the tire back and forth to loosen it, then re-inflate slowly while watching the bead line. Stop and adjust if you see it pulling to one side. This takes a minute but prevents a pinch flat (a puncture caused by the rim pinching the tube).

Once the bead looks even, inflate to the pressure printed on the tire sidewall. Start with a floor pump if you have one — a hand pump works but takes longer. Check the pressure with a gauge to make sure you hit the target.

Reinstall the wheel on the bike

For the front wheel, align it with the fork and push down until the quick-release clicks closed (or tighten the axle nuts). The wheel should not move side to side.

For the rear wheel, pull the derailleur back, lift the chain onto the smallest chainring, and guide the wheel into the frame. Make sure the chain sits on top of the smallest cog. Close the quick-release or tighten the axle nuts. Spin the wheel to confirm it does not rub on the brake pads or frame.

Flip the bike right-side up and take a short test ride to confirm everything feels normal. Listen for any rubbing and check that the brakes still work.

What to do if the new tube keeps failing

If you get another puncture within a few rides, the problem is usually one of three things: debris still in the tire, a damaged rim, or a pinch flat from improper seating.

Go back and inspect the tire interior again with good lighting. Feel for anything sharp you might have missed. If the rim has a dent or burr, it can puncture the tube repeatedly — this requires professional repair or rim replacement.

If the puncture is on the side of the tube (two small holes close together), you have a pinch flat. This means the tube was not seated correctly or the tire pressure was too low. When you install the next tube, spend extra time making sure the bead is even before inflating to full pressure.

Frequently Asked Questions

Can I patch the old tube instead of replacing it?

Yes, if the puncture is small and you have a patch kit. Clean and dry the area, roughen it with the sandpaper in the kit, explore adhesive, wait the time specified, then press the patch on firmly. Patch kits work best for small holes, not for large tears or multiple punctures. Many riders carry a patch kit as a backup for emergencies.

What if I do not have a tire lever?

You can use a flathead screwdriver or even a sturdy plastic spoon, but tire levers are inexpensive and designed not to damage the rim. If you are stuck without one, work slowly and carefully to avoid pinching the new tube or scratching the rim.

How tight should I inflate the tube?

Inflate to the pressure range printed on the tire sidewall — usually something like "80–100 psi" for road bikes or "30–50 psi" for mountain bikes. Use a floor pump with a gauge for accuracy. Hand pumps are slower but work if that is all you have. Check pressure weekly because tubes lose air naturally over time.

Do I need to remove the tire completely to change the tube?

No. You only need to loosen the tire bead enough to pull the old tube out and insert the new one. Removing the tire completely takes longer and is unnecessary for a tube change. You only remove the tire if you need to replace it or repair the rim.

What if the new tube is the wrong size?

It will not seat properly in the rim and will either bunch up or stretch too thin. Do not try to inflate it — return it and get the correct size. Installing the wrong size risks a blowout or when ready puncture.