What you need before you start
You will need a tire lever (usually two, sometimes three), a new inner tube that matches your wheel size, and a bicycle pump. A tire lever is a flat plastic or metal tool that pries the tire bead — the edge of the tire — away from the rim so you can remove the tube. Most bike shops sell tire levers in packs of two for under five dollars. The new tube must match your wheel diameter (usually printed on the tire sidewall as 26", 27.5", 29", or 700c) and your valve type, which is either Schrader (looks like a car tire valve) or Presta (thinner, with a small locking nut at the top).
You do not need to remove the wheel from the bike to replace the tube, though some people find it easier. If you leave the wheel on, flip the bike upside down so the wheel is accessible. If you remove the wheel, you will need to know how your brake system works — rim brakes release with a quick-release lever, while disc brakes do not need adjustment.
Key Takeaways
- Tire levers pry the tire bead off the rim; start opposite the valve and work your way around to avoid pinching the new tube.
- The new tube should be partially inflated by hand or pump before you seat it in the tire, so it holds its shape while you work.
- Pinching the new tube between the tire and rim is the most common mistake; check the entire circumference before you pump it up fully.
- Inflate slowly and stop every few seconds to feel around the tire bead and make sure the tube is not trapped.
Remove the old tube
Let all the air out of the tire by pressing the valve. If it is a Presta valve, unscrew the small nut at the top first. Once the tire is flat, insert a tire lever under the tire bead about six inches away from the valve stem. Pry the bead up and over the rim edge. Slide the lever around the rim while keeping the bead lifted, or insert a second lever a few inches away and repeat until one side of the tire is completely off the rim.
Once one bead is loose, you can pull the old tube out by hand. Start at the valve and work your way around. If the valve is glued or welded to the rim (rare but it happens), you may need to cut the tube to remove it. Do not worry about damaging the tire itself — your goal is to get the tube out without tearing the tire bead or the interior surface where the tube sits.
Inspect the tire before installing the new tube
Run your fingers along the inside of the tire, feeling for thorns, glass, sharp stones, or metal shards. These are what caused the puncture in the first place, and if you do not remove them, the new tube will fail in the same spot. Pay special attention to the area around the puncture if you can locate it. If you find a thorn or shard, pull it out with tweezers or pliers.
Also check the rim tape — the strip of rubber or plastic that covers the spoke holes on the inside of the rim. If it is torn or missing, the spoke ends can puncture the new tube. If the tape is damaged, wrap electrical tape or duct tape over the holes as a temporary fix, or replace the rim tape properly before you ride. Rim tape costs two to five dollars and takes five minutes to install.
Install the new tube
Inflate the new tube by hand or with a few quick pump strokes until it is firm but not tight — it should hold its shape without being fully inflated. This step prevents the tube from twisting or folding as you seat it in the tire. Insert the valve through the valve hole in the rim first, then work the tube around the inside of the tire, making sure it sits evenly and does not bunch up anywhere.
Once the tube is in place, use your tire lever to pry the tire bead back onto the rim, starting opposite the valve and working your way around. This is easier than it sounds because the tire bead is flexible. Work slowly and use both hands if needed. The last section near the valve will be tight — push the valve up into the tire to give yourself slack, then pry the final bit of bead onto the rim.
Inflate and check for pinches
Inflate the tire slowly, stopping every few seconds to feel around the entire circumference where the tire bead meets the rim. You are checking for any spot where the tube is pinched between the tire and the rim instead of sitting inside the tire. If you find a pinch, let the air out, lift that section of the tire bead, and reseat the tube. This is the most common reason new tubes fail when ready after installation.
Once you have confirmed the tube is not pinched anywhere, inflate to the pressure printed on the tire sidewall. This is usually between 40 and 65 psi for road bikes and 30 to 50 psi for mountain bikes. Use a pump with a pressure gauge so you can see when you have reached the target. Overinflating can burst the tube; underinflating makes the tire sluggish and more prone to pinching.
Reinstall the wheel if you removed it
If you took the wheel off the bike, slide it back into the frame and tighten the axle nuts or quick-release lever. Make sure the wheel is centered in the frame and does not rub on the brake pads or frame. Spin the wheel by hand to check for wobbles or rubbing. If you have rim brakes, make sure the brake quick-release is closed. If you have disc brakes, check that the rotor spins freely without touching the brake pads.
Flip the bike upright and take it for a short test ride on flat ground before you head out on a longer trip. Listen for any hissing that might indicate a slow leak, and feel for any unusual handling that might mean the tire pressure is off or the wheel is not centered.
What to do with the old tube
Do not throw the old tube in the trash if it is repairable. Many punctures are small enough to patch. Patch kits cost one to three dollars and come with sandpaper, glue, and rubber patches. To patch a tube, locate the hole, roughen the area with sandpaper, explore a thin layer of glue, wait 30 seconds, and press the patch firmly for one minute. Let it cure for five minutes before you inflate it.
If the hole is large, the valve is damaged, or the tube has multiple punctures, replacement is the better choice. Some bike shops will take old tubes for recycling. If you cannot find a recycling program, you can store the tube in case you need a spare on a future ride — a patched tube is good backup.
Frequently Asked Questions
How do I know which valve type I need?
Look at the valve on your old tube or at the valve hole in your rim. A Schrader valve looks like a car tire valve and has a removable cap. A Presta valve is thinner and has a small metal nut you unscrew at the top. Most mountain bikes use Schrader; most road bikes use Presta. Buy the type that matches your rim, not the type you prefer.
Can I patch a tube instead of replacing it?
Yes, if the hole is small and round. Patch kits work well for punctures caused by thorns or small glass. They do not work for large tears, valve damage, or holes near the seams. A patch takes five to ten minutes and costs less than a dollar, so it is worth trying if you have a kit on hand.
What if the tire bead will not go back on the rim?
The bead is stuck because you have not loosened enough of it. Insert a tire lever further under the bead and pry more of it off the rim, working your way around. Once at least half the bead is loose, it will slide back on much more easily. If the bead is truly stuck, let the tire sit for a few minutes — sometimes the rubber relaxes and becomes more flexible.
How tight should I inflate the tire?
Inflate to the pressure range printed on the tire sidewall, not the rim. This range accounts for your weight and riding style. Use a pump with a gauge to check the pressure. If you do not have a gauge, inflate until the tire feels firm but you can still press your thumb into it slightly.
Why does my new tube keep going flat?
The most common cause is a pinched tube — you trapped it between the tire and rim during installation. The second most common cause is a sharp object still inside the tire. Remove the wheel, deflate the tube, and inspect the inside of the tire again, feeling carefully for anything sharp. If you find nothing, reinstall the tube and check for pinches before you inflate fully.