Patching Innertubes

Often, a tire you have may leak or go flat. The most likely cause of this is that the innertube has a puncture or cut. This document cover how to patch a small puncture or cut in an innertube.

1. Tire forks (x2)
2. Innertube patch
3. Rubber cement
4. Sandpaper (50 grit or lower)

1. Remove any remaining air in innertube by holding down valve.
2. Hook tire forks on tire as shown below in Figure 1.
   
   Figure 1: Tire forks in position to remove tire

3. Use tire forks to remove one side of the tire from the rim (leave the other side of the tire on the rim). The wheel should look like Figure 2 shown below.
   
   Figure 2: Wheel with half of tire removed

4. Remove innertube from tire (be sure watch out for the tube stem when removing innertube). Also be sure to note the orientation of the innertube with respect to the tire. This will make looking for thorns, nails, or other foreign objects stuck in the tire easier later.
5. Find the cause of the leak. One easy way to do this is to partially inflate the tube to 5-10 psi and then listen for leaks or run your hand over it tube. If the leak is very small, then you may want to cover the tube with soapy water and look for bubbles.
6. Once you find the leak, note where it was in on the innertube and go to the tire and see if the object that caused the leak is still in the tire. Run your hand along the inside of the rest of the tire to ensure that no foreign objects are there that may puncture the tube again. Also check to make sure that no spokes are poking through the inside of the rim.
7. Clean and roughen the puncture area with sandpaper.
8. Brush off any loose rubber sand from the puncture area.
9. Apply a small amount of rubber cement to the puncture area making sure to cover the hole. Be sure that the tire is deflated during this step.
10. Allow cemet to dry some but before the cement dries completely, apply the patch to the area. Be sure to apply pressure with your finger to hold the patch down. Allow patch and cement to dry.
11. Reinstall the stem of the tube into the rim and tire. Once you get the stem in, inflate the tire slightly to prevent the tube from twisting inside the tire.
12. Reinstall the rest of the innertube around the tire. Be sure that the innertube is in the tire completely and not pinched between the tire and the rim.
13. Using the tire forks, work the tire back onto the rim.
14. Reinflate the tube.