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Hi folks,
I've got some Hunt wheels on my CX bike that I run as a road bike. I've been using Schwalbe Pro One tyres, running tubeless - I've just bought a new rear and went to fit it last night. Got the old one off, cleaned off all the gunk and put the new one on - it was a right pain to get over the rim, but I didn't think too much of that at the time. I did the initial inflation with no latex, just soapy water and it went on fine - but as soon as I took the pressure off, it popped off the bead. I repeated several times - same result. I inflated it with a tube in and this time one bead settled, but the other popped off again. I thought this was progress, so got the tube out, and tried again... and again... and again...
I figure that I've just bought a tyre that is right at the tight end of the tolerances. I've never had problems with these tyres before (I did check, by the way, it's definitely the right size - 700 x 28c). I've tried leaving it inflated and still attached to the pump overnight in the hope that it will stretch a little. Is there any other trick I can try before I switch to using a tube?
Cheers - Adam...
ratchet strap round the tyre?
Maybe too much soap? Try drying it all off and starting again?
@tjagain - what do you mean? Put the strap on and tighten as it is deflating?
@timbog160 - could be; it's been sitting overnight, so I'm about to see if that has worked - should be no soap now...
The ratchet strap trick is basically an advanced form of pressing down over the valve while inflating. You need the tyre loosely fitted and ready for inflation, then you wrap the strap round the circumference and ratchet down ‘a bit’ (I don’t think there’s a scientific measurement for this). Then inflate. Should nicely pop up with no big drama. It’s holding the tyre in shape, location and briefly reducing volume so assisting inflation.
This is really more a trick for getting a tyre that won’t seat to seat than fixing one that blows off. It’s worth a go, but tbph I’d be taking a good look at the bead, and I’m really not sure I could trust that tyre even if you get it to stay put. As no sealant yet, any possibility of trying warranty return?
Has it definitely snapped on? If you inflate it to 80 psi, say, and it goes up OK, then how does the bead pop off - is it a sort of slow deflation?
Lubed the bead and used the tyre lever trick to lift and seat the tyre on the rim as much as possible before inflating?
Both sides....
Thanks for additional responses...
@vincienup - OK, I understand. It might work if I ratchet it up as I deflate the tyre, as it might help to keep the beads in place. The tyre stays on the bead down to less than 20psi... I could return it - or use a tube...
@Garry_Lager - yes, definitely snapped on. It holds pressure without issues until I deflate it to put sealant and valve core in; then, somewhere below 20psi it pops off the bead with exactly the same sound as a tyre makes as it snaps on.
@rickmeister - the problem isn't getting it to take to the bead, it's getting it to stay there without pressure to hold it in place.
Pour sealant in then inflate it?
Well if it pops on and stays put with pressure it in, what's the problem if it unseats when nearly flat? Just blow it up and ride it.
@scotroutes - tried.
@tthew - haven't worked out how to get the valve core back in without deflating it and can't get enough airflow to pop it onto the bead with the valve core already in place.
Have you tried CO2 with the valve core in?
Glue?
haven’t worked out how to get the valve core back in without deflating it and can’t get enough airflow to pop it onto the bead with the valve core already in place.
Ah, right you are. Have you tied a tubeless inflator? Same theory as CO2, but IIRC that makes the sealant go off quicker.
Is it really definitely seated? I have some tyres that will hold air perfectly even when not fully seated. Best way to check is to spin it in your hands and watch the tyre. Of course that might be tricky if you can't get the hose off without losing air.
Assuming your pump comes off the valve easily (i.e. not screw on) it should be a case of valve off, finger over hole, then swap your finger for the valve core.
@tthew - yes, tried using an inflator - whatever I use I can't get it to seat with the valve core in - just not enough flow.
@pdw - I'm pretty certain it is properly seated (I took it up to 120psi and inspected fairly thoroughly) but I can't spin it as the pump is still attached; as above, can't get that off without losing the pressure and the seating as the valve core is not in...
How many wraps of tape on the rim?? Another go round might help the tyre stay on the shoulder
@carlos - 2, I think. I did wonder if my tape wrapping might have been the problem as I've recently had to redo it (one of the spoke holes had a sharp edge, which caused the original tape to fail at that point, I think). The old tyre had no problem with it, though...
I do love a quality tubeless thread....
Is there no way you can get the valve core in from 120psi to above 20 psi ? Extra pair of fingers purely for the valve core changeover, F1 style.
How about a Milkit kit?
My son's bike was like this and it remains my only tubeless defeat. I could (with some effort) get it to inflate and (sort of) seal on the rim, but the moment the air was let out, the tyre would just fall straight back off the rim again. After dicking about for ages, I just had to accept that I wasn't willing for so much faff in the field, so a couple of ligthweight inner tubes later, we agreed not to talk about it again.
My gravel bike was really, really hard to get inflated (so much so that I now own a dedicated tubeless "boost" pump!) but at least once they were up, they locked on the rim and stayed in place and I've not had any issues with them in the 3 months since I did it.
Tubeless has to be less faff than putting a tube in. As soon as it isn't, it's not worth it and that's the time to give up.
Can't you just pump it up with the core in place? It always works for me. Pour sealant in, pump up tyre, do the shake.
Core shouldn't make that much difference. Which inflator can't inflate a tyre with the valve core in?
Agree with both of Scotroutes comments . Also even if you inflate the tyre without the valve core in you should be able to get your finger over the valve hole and not lose all pressure while re-installing the valve core then just pump it up with a track pump and away you go .
@scotroutes, @njee20 - putting the core in means I can't get the beads to seat. I've tried several times... The inflator is a Schwalbe Tyre Booster, which I think is essentially identical to the Airshot.
I've given up and put a tube in, at least for now. The tyre actually looks like the bead has struggled to seat completely the whole way around - I still think I've ended up with one that is just too small. It's worked with a tube, and (after a wee bit of frigging around with a tyre lever during inflation) the tyre is true when I spin the wheel. I'm hoping, as before, that a few hundred kilometres of carrying my Clydesdale-class engine will stretch it out a little and I can maybe return to tubeless.
Thanks for all the advice!
Adam...
haven’t worked out how to get the valve core back in without deflating it
Quickly 🙂
I had to do that on one of my sons tyres 🙂
@weeksy - screw-on inflator; first time I've realised this is a shortcoming...