Mending a Punctured Tire Tube

Tube punctures are the most common form of a breakdown and it is really easy to learn how to mend them.

#1. Release brake calipers and remove the wheel.

#2. Use tire levers (available from bike shops) to remove the tire treads.

#3. Carefully run your fingers around the inside of the tire tread to check for sharp objects, such as nails, splinters of glass or thorns. Remove the cause of the puncture and check that there are no more spikes in the tire.

#4. Find the hole in the tube, either by pumping it up and holding it under water to look for bubbles, or by feeling for escaping air. There may be more than one hole so check carefully.

#5. Mark the hold with pen or chalk. Use sandpaper or the scratcher from the puncture repair kit to scuff the area around the hole to help secure the glue to the tube. DO NOT USE A WIRE BRUSH!

#6. Spread glue thinly and evenly over and around the hole or holes in the tube and wait for the glue to dry until it feels tacky to touch. Place a patch over the marked hole and apply pressure. (A faster alternative is to use the new glueless patches.)

#7. Lightly pump up the tube. Place one edge of the tube around the wheel rim and push the tube’s valve into the rim’s hole. Starting from the valve, push the rest of the tube into the tire treads. Ensure the valve stem is perpendicular to the rim and that the tube isn’t twisted. Once the tube is inside the tire, begin to place the second edge of the tire onto the rim. About 75% of the tire will go on easily, the rest will need strong fingers or the tire levers to coax it onto the rim. DO NOT PINCH OR DAMAGE THE TUBE! When done, pump a little more air into the tube and check that the tube isn’t caught between the rim and the tire.

#8. Slide the wheel back into place on the bike and tighten the bolts gradually, ensuring that the wheel remains aligned straight to the frame. Reconnect the brakes.

#9. If you are happy with it, fully pump up the tire. Take the bike on a short ride, and test that the brakes are still working correctly.

On long journeys carry a spare inner tube and the necessary tools with you. Its faster to just replace the tire and mend any punctures later when you get home.