Fix a Flat

Our quick-and-easy, no-fail way to swap a punctured tube

If you do even a moderate amount of riding, you are going to get a flat tire at some point. The good news? You can become a skilled flat-repair expert in no time.

What you’ll need:

  • a new tube
  • 2 tire levers
  • a floor pump, hand pump, or CO2 cartridge and inflator

Flat tires will happen, but if you learn how to fix ’em, it’s not a deal breaker. Here’s how:

  1. Unhook your brakes (no unhooking disc brakes) and remove the flatted wheel.
  2. Remove the valve cap. (For Presta valves remove retainer ring if you have one.
  3. Starting opposite the valve, grab your tire lever, hook it under the bead, leverage it down, and push AWAY from your body.
    * If you get stuck, hook your tire lever to a spoke and add another tire lever under the bead three inches away – then give it a push unseating the bead of the tire from just one side.
  4. Remove the tube and make sure whatever caused the flat isn’t still there. Inflate the tube to locate the leak. Run your gloved hand or a piece of cloth along the inside of the tire to feel for any debris penetrating the tread. Now check the outside of the tire for objects that haven’t worked through the tread yet. Remove all debris.
  5. Grab a new tube and give it some air for shape. (For Presta valves unscrew the valve tip and give it a tap to break the seal allowing free movement of air).
  6. Put your valve back in through the rim. Starting at the valve, tuck that tube – then the tire wall back inside of the rim. The last few inches is the tightest – roll the tire onto the rim using the palms of your hands forcing the tire on away from you.
    * When all else fails, use a tire lever, but make sure you don’t pinch the tube in between the rim giving you another flat.
  7. Now, make sure everything’s in place and the tube and tire is centered.
  8. Attach the pump head (most pumps can accommodate both valves), making sure the head is fully on the valve by giving it a little wiggle as you push it down.
    * Engage the pump head by rotating the lever (air should flow freely into the tube); if pressure spikes rapidly with the first few pumps, the head is not fully engaged.

    Reinflate the tube to around 20 psi, then check that the tire is properly seated on both sides of the rim. If it is, fully inflate it to the psi recommended on the tire’s sidewall or to your desired pressure.

  9. After pumping, replace the nut on a Presta valves, tighten valve tip and (cap for Presta or Shrader).
  10. Replace and affix your wheel (don’t forget to re-attach your brakes). Give it a spin to make sure it is on straight.

Now you are ready to get back to the task at hand: riding your bike!