Over the years, I’ve seen many cyclists buying a lot of inner tubes all the time because they didn’t know how to patch their punctured tubes. It’d be much better for the environment and save some money if we can reuse the inner tubes.
Some cyclists did try patching their inner tubes, but failed and gave up. In reality, there’s a correct procedure to do this which I’ll cover below.
- Inner tube
- Patch kit
- Tire levers
- Bicycle pump
- 7 to 10 minutes
1. Deflate the tire completely
In many cases, the tire would be entirely flat already. Otherwise, unthread and press on the small locknut on the valve stem to deflate the tire, and this would make it easier for you to remove the inner tube in the later steps.
2. Remove the wheel
Having the wheel removed will make it a lot easier to work on the tire. If it’s a rear wheel, shift the gears to the smallest cog and the smallest front chainring as it will put more slack onto the chain and makes it easier to remove the rear wheel.
If it’s a rim brake bike, it’ll be using a quick-release system. For disc brake bikes, it can be either quick-release, thru-axle, or a combination of both, depending on the front/rear wheel.
3. Remove the tire
Press the tire bead into the rim center to loosen the tire and makes it easier to insert the tire levers.
Place one tire lever under the tire bead and hook it onto the spoke. Use a second tire lever and place it under the tire bead about 2” away, and move it along the rim to remove the tire.
4. Remove the inner tube
Once the entire rim bead is outside the rim, pull out the inner tube, starting with the valve stem.
5. Locate the leak hole
The leak hole can often be hard to locate especially a slow leak or pinch flat. Inflate the inner tube, if possible to double or triple its size. Feel and hear for any hissing sound of air escaping.
If this doesn’t work, submerge the inner tube in water, and the leak hole will be immediately visible where the air bubbles form.
6. Mark the leak hole
Draw a circle around the leak hole with a marker. Don’t mark directly on the leak hole as it will be sanded off later.
Ideally, you want a bright color for it to be visible. My preferred method is to use a biro as it’s visible even if it’s black.
7. Sand around the leak hole
All patch kits come with a small piece of sandpaper. Gently sand the area around the leak hole that you’ve marked. All you’re doing is to create a slightly rougher surface for the vulcanizing glue to stick on.
8. Use the correct patch size
There can be various patch sizes in your patch kit. You want to use one that is just large enough to cover the leak area entirely.
There are two types of patch kits in the market today; pre-glued and self-vulcanizing patch. My preference is the self-vulcanizing patch. Although it requires a slightly more complex procedure, it’s much more reliable.
9. Apply the vulcanizing glue
Apply the vulcanizing glue on the marked leak hole. You want it to cover an area larger than the patch itself. Use your pinky finger to distribute the glue evenly.
You only need a thin coat. One of the telltale signs of too much glue is the layer looks ‘glopped’.
Wait 4 to 5 minutes for the vulcanizing glue to cure. You can test by touching the fringes, and don’t touch on where the patch will be.
10. Apply the self-vulcanizing patch
Remove the patch from the backing. Remember to leave the clear plastic cover on.
Center the patch on the leak hole. Apply vertical pressure firmly for several minutes, especially on the edges.
Leave the plastic cover on for now as removing it could pull out the newly bonded patch.
11. Install the tube and tire
Insert the tube and reinstall the tire. Inflate the tire back to your ideal tire pressure.
Keep a close eye if there are slow leaks as you ride.
Important things to know
- Patch is a temporary fix. The ideal, reliable and safer, long term solution is to replace the punctured tube with a new one.
- Do have a patch kit in your saddlebag. You never know when you’ll get a double puncture in a single ride.
- Do patch the tube at home, if possible. It can be a stressful situation to patch the kit on the roadside especially with the entire group waiting for you. Use the spare tube instead and patch it at your own pace at home.
- Don’t patch more than twice. The more patches a tube has, the higher chances of one of them failing. Try to minimize the patches to a minimum. For me, I replace my inner tube after two patches.
Don’t use a patched inner tube as spare. This will prevent the chances of the patched tube failing when you need it the most. Always use a new tube as the spare in your saddlebag.