Hi,

Come back from a ride and discover that my front wheel was flat again. I’m using Bontrager tubeless tyre with some sealant in it, around 125 ml. It’s the second time I get a flat, similar hole, a tiny slit in the tyre. Is it the kind of hole a sealant can’t sealed then? If it’s a thorn, i guess the sealant bind around it, but if it’s opened, it won’t work? Or does some sealant works bettern than other?

Thanks.

It’s very erratic, I’ve had pinpricks that won’t seal but others that did, especially on new tyres… Slits seem to be worst though, every puncture I’ve had while out riding that wouldn’t seal up was a slit, I think they just fold back open while riding. Some people say “Tubeless means no more punctures ever” but that’s mince, it does mean lots less though in my experience.

Bang an anchovy in there. Sorted.

I’ve definitely had small punctures that the sealant couldn’t deal with – it’s certainly not infallible. It’s helpful if you notice the puncture straight off, then you can stop and rotate it to the bottom such that it’s sitting in a bath of latex so to speak.

Have to say I’m on a hell of a run without a flat (on tubeless) – specifically remember getting one in the 2007 GT trailquest and can’t recall any since. Cue pinch flats on the tyre bead forward and back next ride 🙂

Sealant very unpredictable IMHO – when I take a tyre off and see all the mangled up sealant then Its clearly worked somewhere, but for punctures that you hear I’ve never experienced it working.

If you want a really big laugh have a root around on the No Tubes website where a nail goes into a tyre and (they reckon) it seals…. 😯

These things work.
http://www.jejamescycles.co.uk/innovations-tubeless-tyre-repair-kit-id31040.html
As long as you catch it before all the sealant has blown out of the hole, they will plug it.

It does also depend on the sealant your using, quantity in the tyre etc.
If you’re using Bontrager Juice then you have little chance of any puncture being sealed. Joe’s and Stan’s seem to work fine though. As GL said, if you know where the puncture is, rotate it to the bottom and it should seal.
The only punctures that it doesn’t seem to fix are when the rim cuts into the tyre – the tubeless equivalent of a pinch puncture. These usually spell the end of the tyre. 🙂

I’ve also had small holes not sealed using Stans sealant, but then, I’ve half ripped knobbles off and with a bit of persuasion the sealant has sealed the rip and I’ve been able to ride home albeit with less pressure in the tyre than normal. Tubeless repair kits also seem to work – seems strange to make the hole bigger to get the seal, but works just fine 🙂