Road tubeless experiences

Wheel is a Giant SLR1 (42mm)

I think there’s a pin hole just where the sidewall meets the rim/lip of the tyre.

It seems to hold pressure until about 50psi and then ssssssssssssssssss

It held 40 odd PSI during the night.

Is it too much to ask the sealant to seal it because of where it is?

You might be lucky if you rotate the wheel so that the sealant is at the hole area the spin the wheel. I’ve had a few tyres that wouldn’t seat at higher pressures but taking them for a ride at the lower pressure allowed me to up the pressure slightly, then after a few more rides get the full pressure in.


@Hlab, I blew it up and held the bike flat and spun the wheel… blew it up again and it held at 80psi briefly, but then it gave up the ghost. Think i’m wasting my time :slightly_frowning_face:

yes, you are. Had a same issue with a Hutchinson fusion once. Same location. Tire was relatively new though so it looked like the sidewall wasn’t strong enough in that area. Because of the close location to the rim the hole would open up again each time I hit a small bump. Replacing it was the only option…


The tyre is moving too much in that location and the hole opens up again, had that before. If you want to save the tyre, take it off and put a tube patch inside over the hole. It won’t stick well at first (because the tyre isn’t rubber inside), but if you leave it overnight or so, it’ll be ok.


I’ve had success sealing some holes with putting the wheel on its side and spinning but if its not doing it quickly for you it probably isn’t working :-/


As I suggested above, if its holding at 40psi take for a ride (the worst wont happen but dont go somewhere you can’t get back from), the next day try 60psi and take it for a ride and finally on another day take it to 80psi. Ive had tyres that would hold pressure initially aftter a few rides hold fine; I think the centrifugal force of an an actual ride does what spinning by hand tries to do but more effectively (dispersing the sealant into all the nooks and crannies).

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Thinking out loud here.

I have seen someone run tubeless on the non tubeless wheels I contacted Fulcrum about above where Fulcrum responded saying the wheels are not Tubeless compatible as they don’t have the “humps” to stop the tyre popping out

So if they don’t have the humps that stop the tyre “popping out”, what stops the tyre popping out when it’s set up with a clincher and tube?

(The wheels don’t have spokes on the internal rim, so they don’t even need tubeless tape.)

I did similar but with 1st Swisside Hadrons 625 clinchers. Their support actually got back to me with a ‘sure, go ahead’ and gave me instructions how to do so. But after a wee bit more research I decided against it. I can be a nervous descender as it is :joy:

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The risk afaik is from the tyre pushing inwards and “burping”, but tubes don’t burp.

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The air pressure in the tube pushes outwards and presses the tire bead into the rim’s hook. This prevents lateral forces from pushing the bead off the hook. In tubeless, the hump or shelf is the mechanical equivalent. Essentially with tubeless you are jamming the bead into a channel and friction counters the lateral forces.

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Did a little experiment, fitted a tubeless to the wheel in question… filled up with CO2 and it held pressure no problem.

But, when i let it down quickly, the sidewalls slipped into the centre of the rim.

I had the same issue when I got a big puncture on Schwalbe Pro Ones (looks like that’s what you’re running?). Virtually all other tubeless tires I’ve used will stay seated if they go flat.

Yeah, Pro One… but it’s not on a wheel advertised as tubeless.

They stay seated on my tubeless wheels ok :+1:t2:

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You can inflate them tubeless, and even ride them. Even the pro ones, they might come off when they’re new, but they’ll be fine when inflated (I’ve had the pop-off when flat on tubeless rims too). However, it’s not recommended.

In MTB, it is (or was) quite common to run tubeless tyres on non-tubeless wheels. But the pressures involved are much lower than on the road, and the higher-volume tyre probably deforms easier without putting stress on the rim-bead seal.

I wouldn’t do it on the road. You don’t want your tyre coming off at 30mph in a corner on concrete.


So what happens with a puncture with a tube?.. the tyre must also slide into centre if puncture is big enough?

The tyre does come off with tubes. But usually its not instant. A tubeless tyre can come off instantely.


Ok cheers. :+1:t2:

Like @splash posted, there is still some mechanical grip there but if you kept riding or tried to changing direction with any speed above a slow walk, the tire would likely pop off the rim. One of numerous reason pros (and CX racers) use tubular tires is that since they are glued to the rim, they won’t come off (easily) when flat so they can continue for as long as needed before a replacement arrives without fear of tire letting go and crashing.


Burps are still common with tubeless at less than 20psi in cross especially if you are heavy. One of the tricks if your tires easily pop into the center channel when deflated is to add an extra wrap of rim tape. Makes the tire harder to mount/dismount but makes them safer in the case of a flat or burp.