Inner Tube Repair
This article will discuss the patching of bicycle inner tubes. Both pre-glued patches and the vulcanizing patches will be reviewed.
Locating the Hole
- Wheel Removal and Installation - View Article
- Tire and Tube Removal and Installation - View Article
- Patch kit such as the GP-2, VP-1
- Tire boot such as the TB-2 for temporary repair of damaged tires
- Pump: either a floor or hand pump. An air compressor with correct fittings (such as the INF-2) can also be used.
- Useful items: marking pen, rags, alcohol solvent
To fix a flat, first locate the hole in the inner tube. If possible, re-inflate inner tube to at least twice its normal width.
Inspect for air leaks by holding tube close to the sensitive skin of lips or by holding tube near your ear to hear leaks. Move the tube around its circumference. If these steps do not work, submerge tube in water and watch for bubbles at the hole.
Once you have found the hole, use a marking pen to mark it. Make four marks, one to each side of hole. Do not mark close to hole, as the mark may be sanded off.
To prepare the tube for patching, clean the tube by lightly abrading area around hole. Most patch kits include a small piece of sandpaper, but a separate piece of sandpaper or fine emery cloth is also acceptable. Excessive sanding or heavy pressure can cause grooves in the rubber, which may lead to patch failure.
If possible, clean the area using a clean rag and alcohol, or any solvent that doesn’t leave a film. Allow the area to dry completely.
Patching an Inner Tube Using the GP-2 Super Patch Kit
The GP-2 Super Patch Kit uses pre-glued patches. There is no tube of glue.
- Peel patch from patch backing. Handle patch as little as possible and by edges only.
- Center patch to hole and lay patch on tube.
- Apply pressure to patch to assure seal. Roll patch and tube between thumbs and forefingers.
- Tube is ready to install. DO NOT test patch by inflating tube while outside of mounted tire. This may stretch tube body and weaken patch bond.
Patching an Inner Tube Using the VP-1 Vulcanizing Patch Kit
Glue type patches such as the VP-1 Vulcanizing Patch Kit require the application of a thin layer of self-vulcanizing glue on the tube before the patch is applied.
- Open glue tube and puncture seal. Apply thin coat of glue and spread evenly around hole area. Spread area of glue larger than patch size. Use a clean finger or back of patch to spread glue evenly in a thin layer. Do not apply too much glue. Glue layer should not appear “glopped” on.
- Allow glue to dry. This may take several minutes. Test by touching only perimeter area of glue, not where patch will contact
- Peel patch from patch backing. Handle patch only by edges
- Center patch to hole and lay patch on tube
- Apply pressure to patch, especially at edges
- If possible, maintain pressure for several minutes
- After a minute or two, inspect the bond of the patch to the tube, seeing that all edges look adhered to the tube surface
- Leave clear plastic cover on patch
- Mount tube inside tire and inflate
NOTE: Leaving on the cellophane cover over the patch will allow the patch to slide inside the tire and reduce stress on the fresh patch. If the cellophane is removed, use a dusting of talc or baby powder over the patch.
Temporary Repair of Tire with TB-2 Tire Boot
If the tire has been ripped and the casing damaged, it may not hold an inner tube. It is possible in some cases to make a temporary repair with a tire boot such as the TB-2. A booted tire should not be considered a permanent repair. The tire should be replaced as soon as possible.
- Locate rip in tire. Compare rip to size of tire boot. Tire boot must completely overlap rip to be effective.
- Wipe clean inside of tire adjacent to rip.
- Peel off backing of boot. This is the side opposite of the logo.
- Align patch so edges do not extend beyond tire bead. If necessary, cut boot so it does not extend past tire bead.
- Center patch to rip and press patch to inside of casing.
NOTE: Always replace ripped tires as soon as possible.