How to Patch a Bicycle Inner Tube, by Park Tool on YouTube. 6 min 46 s.
- Video length
- 6 min 46 s
- Time to do it
- 20 minutes
- Difficulty
- Easy
- Steps
- 8
What you need
Steps
Let the air out of the tire, then use tire levers to unseat one bead and pull the inner tube out of the tire.
Inflate the tube a little and run it through a bucket of water. Watch for bubbles escaping to find the hole.
Mark the hole with a marker or chalk, then check the inside of the tire for glass, thorns or sharp edges that caused the flat.
If the tire has a cut or tear, fit an emergency tire boot on the inside of the tire casing before you refit the tube.
Deflate the tube and clean and roughen the area around the hole with the sandpaper or scraper from your patch kit.
For a pre-glued patch, peel it from its backing and press it firmly over the hole, then hold it down for a minute.
For a vulcanizing patch, spread a thin layer of glue on the tube, let it dry until tacky, then press the patch on and hold it.
Inflate the tube slightly and check the patch holds air, then refit the tube, seat the tire bead and pump to your normal pressure.
Tips and common mistakes
Let the glue on a vulcanizing patch dry until it looks dull before you apply the patch, or it will not bond.
Find the hole first and match it to the tire so you can remove the sharp object still stuck in the casing.
Carry a pre-glued patch kit and tire levers on rides so you can fix a flat on the road.
Do not over-tighten the valve or force the pump head, since a bent valve core causes slow leaks.
Questions
Can I patch a tube more than once?
Yes, several patches on one tube are fine as long as they do not overlap and the tube is not torn or stretched around the hole.
How long should I wait before riding?
Pre-glued patches hold right away. Vulcanizing patches bond best if you give the glue a few minutes to set before inflating to full pressure.
When should I replace the tube instead of patching it?
Replace it if the hole is a long split, near the valve, or if the tube has many patches already. A torn tube can fail again.
This guide was drafted from the video's details and general task knowledge. It has not been checked against the full video. Check the video and relevant product instructions before following a procedure. Report a correction.
