Articles, Blog

How to Patch a Bicycle Inner Tube

August 29, 2019

In this video, we’re going to show you proper
use of a patch kit on a bicycle inner tube, including pre-glued patches, self-vulcanizing
patches, and emergency tire boots. We’ll also show you things to watch out for to
avoid getting more flats in the future. Hello, Calvin Jones here with Park Tool Company. First, let’s go over the tools and supplies needed. You will need tire levers to remove the tire
and tube, a pump or method to inflate the tire, a marker to mark the hole
and a patch kit. The most reliable fix for a punctured inner tube is to simply replace it with a new one. However, if the hole is smaller than the patch,
it may be possible to repair it. This process begins with the tire and tube
already removed from the rim. If you need help with the removal process, see this video: If you have a flat, knowing the cause can help prevent future flats, so always inspect the components:
the tire, the inner tube, and the rim. When possible, reinflate the inner tube to at least twice its normal width and look for leaks. By over-inflating the tube, you’re allowing any small
pin-holes in the tube to be detectable. Listen and feel for air escaping the inflated
tube. Be sure to inspect the entire tube. In some cases, immersing the inflated tube
underwater will make the hole easier to find. If you plan to repair the tube, mark each
hole, then deflate the tube. The type of hole tells us about how the tube
was punctured, and helps us prevent another flat. A small pin hole in the tube may indicate
a puncture from a thorn or small wire. Feel carefully inside the tire body as you look for thorns, pieces of wire, glass or metal. Remove whatever you find. If there is something stuck in the tire tread
but it has not gone through the casing, the tire is not compromised.
Remove the object from the tread. A single or pair of short cuts along the side
indicate the wheel hit something while riding, such as a pot hole or rock. These are called “snake bites”, and can also
be the result of running too low of air pressure. A blow out often appears as a large shredded hole. The tube may have poked out through
a rip in the tire casing. A blowout can also be caused
by an improperly seated tire. With the tube outside the tire,
it has no support and it blows out. This type of blowout looks like a long horizontal slit. If there’s a rip in the tire’s casing, the
tire should be replaced as soon as possible. As a temporary fix, you can use the
Park Tool TB-2 tire boot. Peel the backing and apply over the damaged area. If you have inspected the tube and find no holes, it is possible the leak was at the valve core. Put some soapy water on the valve
and inspect for any bubbles. Schrader valve cores and removable
Presta cores can be tightened using a valve core remover
such as the Park Tool VC-1. Finally, inspect inside the rim. Look for
problems such as holes or failure of the rim strip. Here the rim strip is damaged at an eyelet, meaning
it will not support the inner tube under pressure. In this wheel, the spoke is a bit too long
and is poking into the inner tube. Once you have located and marked the hole,
it is important to clean the area. One method is to use the sandpaper
that comes with the patch kit to clean by scraping a larger area
than the patch you will use. When possible, wipe the area clean using solvent that doesn’t leave a film, such as alcohol. Allow the area to dry completely. When using pre-glued patches,
such as the Park Tool GP-2, peel off the adhesive backing
and lay the patch squarely over the hole. Apply pressure to the patch to seal the hole. The tube is ready to install inside the tire. Do not test the patch by inflating
the inner tube outside of the tire, as you may stretch the inner tube
beyond what the tire body allows. This pulls on the patch and weakens the bond. If you are using a vulcanizing patch kit such as the Park Tool VP-1, begin by puncturing the tube of fluid. Apply a thin coat of fluid. Use a clean finger or the back of the foil patch to spread the glue evenly around the area of the hole. Don’t be in a hurry to stick on the patch.
Allow the fluid to dry – this may take several minutes. Test by touching the very edge of the fluid. Peel off the foil backing from the patch,
trying not handle the surface. Apply the patch to the tube, centered on the hole. Apply pressure to the patch, especially around the edges. Leave the clear plastic cover on the patch – it reduces the friction and rubbing on the new patch. After a minute or two, inspect the bond of the patch to the tube, seeing that the edges look adhered to the tube surface. The tube is ready to be installed in the tire or packed away as a spare for the next ride. When packing a repaired tube, bleed out the air as you roll it up. This keeps the size to a minimum. If you need help reinstalling the tube, see this video. And that’s the basic process of
how to repair a bicycle inner tube. Thanks for watching, and be sure to subscribe for the latest videos from Park Tool.


  • Reply Sebastian Murphy May 26, 2019 at 10:54 am

    Use a push scooter if you can't be bothered with fixing punctures.

  • Reply blueridgepics May 30, 2019 at 2:34 am

    Thank you!!! A great video. I've been riding for many years but it doesn't hurt to have a refresher course every now and then. 🙂

  • Reply Awesome Sauce! June 12, 2019 at 11:00 pm

    I wet glue the patch to the tube for a stronger bond. Then carefully peel away the clear wrapper.

  • Reply SFF Author B.L. Alley June 25, 2019 at 5:32 pm

    On the trail or side of the road, reverse the process: Remove the tube but keep in in the same position in relation to the tire (or mark them both in the same spot). Examine the tire for the foreign object and once you found it you'll know where to look on the tube for the puncture. Remove the object and patch the tube.
    When partially inflating the tube to reinstall, use your mouth to blow air into it rather than use the pump. That will prevent over-inflating and popping the patch.

  • Reply lurkerrekrul June 27, 2019 at 6:58 pm

    5:00 – Yup, you always have to pop open a new tube of glue, since the one you used last time a month ago will be completely dried up.

  • Reply Ercushka Kulmetov June 28, 2019 at 5:44 pm

    Or just buy a foam tube.

  • Reply GOPRO MOUNTAIN Bike July 3, 2019 at 3:01 am

    It sounds like gun shot bike tube to much air

  • Reply Brian G July 4, 2019 at 2:36 am

    I found Flex Tape works great. Clean and roughen like usual, then partially inflate the tube and quickly apply the tape. This tape isn't flexible as the name implies. It's just the trade name. I cut little squares for my repair kit.

  • Reply Erin Quinn July 9, 2019 at 9:22 am

    your videos are brilliant

  • Reply Jim Mason July 22, 2019 at 7:59 pm

    I had to do this today with my mtb. Pinhole in the tube and could not find a hole in the tire at all! Pain in the butt.

  • Reply Dylan Baker July 26, 2019 at 7:16 pm

    Can you use super glue to help secure a patch

  • Reply Lisa Petillo July 27, 2019 at 4:01 pm

    Love this guy! Thank you for posting all of the very informative videos!!

  • Reply Miguel Lopez July 27, 2019 at 8:50 pm

    I was doing it wrong this whole time, I put the patch right after I put the glue. Thank you 🙏

  • Reply Joshua A August 2, 2019 at 6:50 pm

    Can I just use duct tape?

  • Reply sQWERTYFALIEN2011 August 10, 2019 at 5:33 am

    . . . . . I had a tube of glue and it actually said : "step 5 DO NOT LIGHT THE GLUE ON FIRE !" they Must be referring to my older Brother ! LOL

  • Reply swissarmychainsaw August 17, 2019 at 1:49 am

    You guys are great! Thanks for all the videos! Park Tool only in my kit!

  • Reply Ants Arumäe August 19, 2019 at 7:25 pm

    If in using a vulcanizing patch do I need to let the fluid dry completely or do i have to put on the patch when it is not completely dry

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