Having issues getting some new tyres to pop up, Mavic 419 UST rims, Panaracer Gravelking 42c TLC tyres. Been running MTB and road tubeless for some time, so am quite familiar with the process, but I've never known a tyre less interested in popping onto the rim*. There is just too much of a gap between the bead and the tape, and the tyres have been folded in the packaging for a while I guess, so are not tyre shaped!
I set them up with tubes last night just to get it back on the road (I'm using this bike to commute 2 days a week), which should help get them more tyre shaped. Can I just put another layer of gorilla tape over the existing layer to try and tighten the bead up enough to pop it out, or is it worth stripping it all out and re-taping with 2 layers? Is there anything else I could try? (It's been running tubeless with other tyres previously).
I still find it interesting how variable tubeless can be. MTB stuff for the most part these days you can just use a track pump and they will pop on, I was even surprised with the 2 road bikes that there was near zero fuss. I'm guessing its just an unlucky tyre/rim combo.
*I have a compressor, and the valve core had been removed.
It shouldn't need any tape if it is a UST rim but, yes, more tape should fix it!! That has always been my solution, so far it has always worked 🙂
Some tyres do fit very loosely, just as some others fit very tight. It can even vary between the same model of tyre, I guess it just depends on factory variances
Things I am sure you have already tried:
- washing up liquid solition
- pulling the bead over to the side of the rim, particularly near the valve
- now that you have inflated with a tube, leave one bead in place as you remove it and then place the wheel on its side (on top of a bucket or a bin is good for this) with the now-unmounted bead on the bottom (so that gravity is helping to line it up with the rim wall) and inflate.
I gave up trying to fit a Magic Mary to Hopetech Enduro rims. Tried everything and nothing would get it to seat. Ended up with new wheels (DT Swiss E1900 Spline).
Same tyre went on in one go, no fuss... First time I've ever had problems fitting a tyre.
Yeah, Mary's like that for me on Hope 'Tech' Enduro - all other tyres go up first time with inflator.
Trick I used was to seat the tyre with a tube, carefully just release one bead, remove tube and then re-inflate tubeless.
Cheaper than buying another wheelset !
Yeah, I'll give that a go I think, how long is it worth leaving the tubes in before having a go at this?
When I was fitting Maxxis DHR2 and DHF to my bike the other week I got the DHR2 on in seconds with my Joe Blow pump. The DHF was a proper pain and I almost gave up. It was a much looser fit over the rim tape.
In the end the trick I came up with was to push the tire up towards the rim edge away from the valley the rim tape runs over. Pushing from the opposite side through the tire. Then carefully repeated same from the other side taking care not to let the first side push back to the middle. Took a couple of minutes, then the Joe Blow inflated it no problem. Just need to push it enough that it bites and takes up the gap to get a seal.
steel4real, yep... tried that.
Tried strapping it up, 4 layers of tape etc. Still no joy!
how long is it worth leaving the tubes in before having a go at this?
Just as long as the bead had 'popped' onto the shoulder then you can take the inner tube straight back out again
Mavic 419 UST don't need tape to make them tubeless. They are supplied with a UST rim strip. Are you not using this?
The UST rim strip came to me damaged, messers Cannondale kinked the hell out of it using it as a standard rim tape with tubes when the bike was shipped, its never going to hold air again. Gorilla tape is what I have on the shelf.
In reality though, with the slack between the rim and the tyre with these Panaracers, I'm pretty sure the UST strip would not be helping in the slightest...
The 419’s a funny one. It has spoke holes and needs tape or a conversion kit so isn’t truly UST. I think it must have a square UST bead.
As above, ordinarily UST wouldn’t need tape or sealant although sealant obvs helps I’m running.
If the beads are refusing to pop even with soap, I think you mush have just hit on a combination that won’t work or have a tape fault - unless there’s something odd about the supplied strip apart from the kink. Is it much deeper than tape? Is it worth fitting it then taping over to seal or is it completely beyond rescue?
The tape has kinked, and as its quite a hard plastic I'm pretty sure there is no rescuing it. I'll have another go over the weekend, I'm pretty happy that with 2 layers of tape I'll trap enough air inside it to pop it on.
Its not the beads popping that is the issue, I just can't get enough air in fast enough to bring the sidewalls out to the rim.
Use a split tube & save yourself all this needless hassle. 😉
I built a pair of wheels with Superstar's XC Carbon rims for my son's light race bike and [i]nothing[/i] would even get the tyres (Nobby Nice TRs) to inflate, never mind seal. I did eventually get them up by leaving then inflated with a tube for a few hours and then carefully removing it and reinflating. This got them blown up, but they leaked so much that they would have needed a gallon of Stan's to stay up.
I abandoned it at this point and threw some Conti ultra light tubes in instead as any tyre that is that difficult to deal in the workshop will always end up being a nightmare on the trail.
No regrets - sometimes these things just don't work out and three months in, we've had no issues with the lightweight tubes.
Just to come back on this one, I've not had time in the interim to try these again, so thought I'd have a go tonight. The bike has had the tyres on with tubes in it for ~7 days/~120 miles.
I didn't touch the tape, didn't make much effort to not disturb the second bead, just took the tubes out, popped in the vales and attached a compressor, both popped straight on within a second!
Added Stans goop through the valve and both are holding pressure.
Definitely worth having tyres fitted with tubes for a while first if people are struggling.