Tubeless Tips Series: Detecting Leaks
Filed Under Articles
It seems everyone is going tubeless these days. From mountain bikers to now road bikers. Even the on the Tour de France, they’re are riding tubeless. So with that, we’re putting together a series of collected tips for tubeless riders. Everything from repair and installation to what you need to bring with you on a ride. Hope you find them useful!
Repair and Leak Detection for tubeless tires
General tubeless repair strategy
If you can’t detect the leak (see leak detection below) and you aren’t in a big hurry, you can replace components one at a time until the leak down rate is acceptable. This lets you isolate the cause of the leak to the defective component and reduces the cost of the repair.
You can also use a tube in the tubeless tire or install a standard tire and tube to repair a leak on these wheels. You have to remove the inflation valve to do it, and you can also exchange the rim strip for a lighter one to save a little weight too.
Tubeless Tire Punctures
Normal patches will work on the inner surface of a tubeless tire. The inner surface of the tire must be clean, dry and abraded lightly to be patched reliably. “Glue-less” patches work also. The same rules apply to make sure the patch adheres well. The inner surface of the tire must be clean, dry and abraded lightly to work well.
Casing Failure (pinch flat or sidewall blowout)
It is often possible to repair a damaged casing in order to ride out on a given day. It is only good for an emergency repair so replace the tire before the next ride.
Use a dollar bill or some other fibrous material to cover the fracture in the casing on the inside surface of the tire. There is a limit to the size of the hole you can repair this way. Some adhesive on the material can help hold the reinforcing material over larger holes. You will need to install a tube in the tire after you repair this type of failure unless you are using a fibrous material that is not permeable to air and it is sealed to the casing well. You should not inflate the tire more than necessary to finish the ride.
Leak detection: Bubble Test
This test is the best way to find leaks in the tire. You can find multiple leaks in this type of test too, a common problem with some types of thorns. The bubble test is not always a reliable way to locate leaks between the bead and rim strip. Air that leaks anywhere around the circumference of the tire bead will almost always come out only at the inflation valve. The spoke nipples typically seal well enough that air will not make it through the spoke holes.
Immerse the tire and rim in water. You need to have a fairly large container for the water in order to submerge the full tire and rim for 4 or more spoke holes. A bathtub, sink or large utility basin or any other large vessel is ideal for this test.
If an initial bubble test shows that the leak is inside the rim cavity (bubbling through the inflation valve clearance hole in the spoke bed of the rim) and you want to isolate a leak location, then seal the valve outlet area with an oil based clay or other non-permanent caulking material and try to force the bubbles out of the spoke holes near the leak. It is generally easier to substitute parts to cure a leak.
You can’t perform a bubble test on an unmounted tire or if it leaks too fast to immerse. If you have a tire that leaks but can’t inflate it enough to use the bubble test to find the leak, and you can’t hear the leak, you have to substitute components to repair the leak. You can replace everything that might be leaking to fix it fast or you can replace things one at a time to find the defective part. Then you can replace the part that is defective instead of all of the parts in the assembly.
Leak detection: Aural Test
If you can inflate the tire you can listen for leaks. You have to be in a very quiet environment to do this. Not all leaks are detectable in this way.You can detect some internal leaks by slowly rotating the wheel as it is partially submerged in water (about 6 inches deep). As you rotate the wheel and an internal leak is submerged you will hear a noise caused by the bubbling water inside the rim. You cannot see an internal leak but you can find it’s general location in this way. This can be helpful when you are trying to find a leak between the tire and rim strip.
If you hear a leak in the tire, test the likely spots with saliva. If you cover a hole with saliva the noise of the air escaping will get louder and also be visible. This can be useful when you’re out on the road or trail.
Related posts:
- Tubeless Tips Series: Leak Repair
- Tubeless Tips Series: Inflation valves, rims, spokes
- Tubeless Tips Series: Rim Strip Issues
- Tubeless Tips Series: What to bring on a ride
- Tubeless Tips Series: Tips and Tricks
Comments
No Responses to “Tubeless Tips Series: Detecting Leaks”
Leave a Reply
Soap and water works better then a tub of water, a slow leak will not show up due to the water pressure holding it back in.