How to Repair a Bicycle Puncture

The tire is the part of the wheel that makes contact with the road--the tube is located inside of the tire, and contains the air giving the tire support.

Bicycle tires have an internal tube that, when filled with air, provides the wheel with support. If the tube is punctured, the air contained within will escape, causing the tire to go flat. While tubes are fairly inexpensive, it is more cost-effective to attempt to fix the tube than to replace it. In many instances, a punctured tube can be repaired using a low-cost tire repair kit, which can be found at most retailers selling bicycles and bicycle accessories. The contents of kits will vary depending on brand and price, but the basic items included in a tire repair kit are patches, tire glue and sandpaper.

Things You'll Need

• Bicycle tire repair kit
• 15 mm crescent wrench
• Tire lever
• Air pump

Instructions

1. Turn the bike upside down so it is resting on the seat and handlebars.

2. Remove the bolt at the center of the rim of the wheel to be worked on. Once the bolt is loose, remove the wheel. You might need to unhook your brakes to get the wheel off. To unhook the brakes, squeeze the brakes together, then slide the brake cable out of the brakes. The brakes will now be loose, and the wheel will fit between them for removal.

3. Slide the flat end of the tire lever between the tire and the rim, then pry the tire out. Work the tool around the entire wheel to remove the tire. Use a second tire lever to hold the tire off of the rim if the tire keeps slipping back into place. The tire lever can be attached to the spokes using the notch on the bottom of the tool to hold the tire off the rim. The other tire lever can then be used to remove the rest of the tire.

4. Over-inflate the tube once the tire has been removed. The over-inflation will help to locate the puncture. If you cannot see the puncture, listen for the leak, as you may be able to hear the air escaping from the tube. If you are still unable to locate the leak, try submerging the inflated tube in water and look for the bubbles produced by the escaping air.

5. Draw a circle around the area of the puncture, then draw an “X” inside of the circle, with the two lines crossing at the puncture location. If the leak is by the valve or if the tire is severely torn (more than just a puncture), you will need to replace the tube.

6. Release all of the air from the tube by connecting the air pump to the air valve and allowing the air to escape. You will be able to hear the air escaping from the tube.

7. Sand the area around the leak using the sandpaper that is included with the tire repair kit. Sanding will create a coarse surface, allowing the patch to be attached more firmly.

8. Spread the glue over the area to be patched. The glue should be applied to an area slightly larger than the patch itself. Allow the glue to dry, which should take about five minutes.

9. Place the patch on the tube and apply heavy pressure for at least 60 seconds. Achieve heavy pressure by standing on the patch, applying all of your body weight, to bond the patch to the glue. Remove the plastic from the patch to complete the repair.

10. Replace the tire, reconnect the wheel and brakes, then inflate the tire.

Tips & Warnings

• Avoid breathing the glue fumes, as they may be toxic.

References

• Bicycle Universe: How to Fix a Flat Tire