What You Need Before You Start

Changing a bicycle tube takes about 10 minutes once you have the right tools. You will need a new tube (the correct size for your wheel — check the sidewall of your current tire), two tire levers, and a pump. Tire levers are flat metal or plastic tools that pry the tire away from the rim; they cost a few dollars and come in pairs. A hand pump or floor pump works, though a floor pump is faster and easier on your hands.

Before you begin, find a clean, flat surface to work on. Lay the bike on its side so the wheel you are fixing points up and away from you. If the puncture is on the rear wheel, shift the chain to the smallest cog first — this gives you more room to remove the wheel.

Key Takeaways

  • Remove the wheel by opening the quick-release lever (or unscrewing the axle nuts), then slide the wheel out of the frame or fork.
  • Pry one side of the tire away from the rim using a tire lever, then work your way around until the entire tire bead is free.
  • Pull out the old tube, then inspect the inside of the tire for thorns, glass, or sharp objects before installing the new one.
  • Partially inflate the new tube before seating it in the tire, then work the tire bead back onto the rim by hand and with the levers.
  • Inflate to the pressure printed on the tire sidewall, checking that the tire bead sits evenly on both sides of the rim as you pump.

Removing the Wheel

Open the quick-release lever on the side of the wheel hub by flipping it outward. If your bike has axle nuts instead of a quick-release, use a wrench to unscrew both nuts. Once the axle is loose, lift the wheel away from the frame. On the rear wheel, you may need to pull the derailleur back with your hand to create slack in the chain, then slide the wheel forward out of the chain.

Set the wheel on the ground in front of you, with the valve stem pointing toward you. The valve stem is the small metal or plastic tube sticking out of the rim where you pump air in.

Removing the Tire and Old Tube

Unscrew the valve cap and let any remaining air out of the tube. Insert a tire lever under the tire bead — the edge of the tire that sits on the rim — about 6 inches away from the valve stem. Pry the bead up and over the rim edge. Hook the other end of the lever to a spoke to hold it in place, then insert the second lever about 12 inches away and repeat. Work your way around the wheel, spacing the levers evenly, until one full side of the tire bead is free from the rim.

Once the bead is loose all the way around, you can usually peel the tire away by hand. Reach in and pull out the old tube. Do not discard it yet — you may need it to figure out what caused the puncture. Inspect the inside of the tire carefully, running your fingers along the inner surface to feel for thorns, glass shards, or sharp metal. Even a tiny piece left behind will puncture your new tube when ready.

Installing the New Tube

Before you touch the new tube to the rim, partially inflate it by hand pump or floor pump — just enough so it holds its shape and is not completely flat. This prevents the tube from twisting or pinching as you seat it in the tire. Screw the valve stem through the rim hole first, then tuck the tube evenly inside the tire all the way around the wheel.

Starting opposite the valve stem, use your hands to work the tire bead back onto the rim. Push the bead up and over the rim edge, working your way around in both directions toward the valve. When you get close to the valve, you may need a tire lever to pry the last section of bead over the rim. Be careful not to pinch the new tube between the lever and the rim — slide the lever under the bead, not under the tube.

Inflating and Checking Your Work

Once the tire bead is fully seated on the rim, attach your pump to the valve stem and begin inflating. Pump slowly and watch both sides of the tire as it fills. The bead should sit evenly on the rim on both the top and bottom — you should see a thin line of the rim showing between the tire and the wheel on both sides. If the bead is pinched or sitting unevenly, stop, deflate slightly, and work it back into place by hand.

Inflate to the pressure listed on the sidewall of the tire. This is usually between 40 and 100 psi depending on the tire width and type — road tires run higher, wider tires run lower. Use a floor pump with a built-in gauge, or check the pressure with a separate gauge after you finish pumping. Overinflating can burst the tube; underinflating makes the tire sluggish and can cause pinch flats.

Reinstalling the Wheel

Lift the wheel and slide the axle back into the frame or fork. For the rear wheel, pull the derailleur back and guide the chain onto the smallest cog as you slide the wheel forward. Make sure the axle is fully seated in both dropouts — the slots where the wheel attaches. Close the quick-release lever firmly, or tighten the axle nuts with a wrench until they are snug but not so tight that you cannot turn the wheel by hand.

Spin the wheel to make sure it does not rub on the brake pads or frame. If it does, the wheel may not be centered in the frame — remove it and reseat the axle. Once the wheel spins freely, you are done.

Common Mistakes to Avoid

The most common error is leaving a sharp object inside the tire. Even if you think you found the culprit, run your fingers around the inside of the tire again. A second puncture within a few miles means you missed something.

Another frequent mistake is pinching the new tube between the tire bead and the rim while you are seating the tire. This creates a small hole that will leak within a few minutes of riding. If you hear a hiss shortly after you finish, deflate and check for a pinch flat — you will see a small crease or hole in the tube.

Overinflating is also common, especially with a floor pump that feels straightforward to use. Check the sidewall pressure limit and use a gauge. Riding on an overinflated tire feels harsh and can damage the tube.

Frequently Asked Questions

How do I know what size tube to buy?

The size is printed on the sidewall of your tire in a format like "700x25c" or "26x2.0". Write this down or take a photo before you go to the shop. The tube package will list which tire sizes it fits. Tubes are inexpensive, so buying one slightly larger is safer than one too small — a tube marked for 700x28c will work in a 700x25c tire, but not the other way around.

Can I patch the old tube instead of replacing it?

Yes, if the puncture is small and you have a patch kit. Patch kits cost a few dollars and include sandpaper, glue, and rubber patches. However, if the puncture is near the valve stem or if the tube has multiple holes, replacement is faster and more reliable. Keep a patch kit as a backup for when you get a flat far from home.

What if I cannot get the tire bead back onto the rim?

The bead is stuck because the tire is too tight or the rim is dirty. Deflate the tube slightly to reduce pressure, then try again. If the tire is very stiff, walk around the wheel and work the bead onto the rim a little at a time rather than trying to force one section all the way on. Clean the rim edge with a dry cloth to remove dirt or dried sealant that might be causing friction.

How tight should the quick-release lever be?

Close it firmly enough that you cannot open it with one finger — it should require your whole hand and a deliberate motion. If it is too loose, the wheel can shift during riding. If it is too tight, you will struggle to remove the wheel next time. The lever should be parallel to the frame when closed.

Why does my new tube keep going flat?

You likely missed a sharp object in the tire, or you pinched the tube while seating the tire bead. Remove the wheel, deflate the tube, and inspect both the tire interior and the tube for holes or creases. If you find a pinch flat (two small holes close together), the bead was not seated evenly. If you find a single hole, search the tire again more carefully.