Seating Tubeless Tyres - Rapid inflation through Presta Valve

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WheezyWheels
Posts: 3
Joined: 30 May 2023, 6:08pm

Seating Tubeless Tyres - Rapid inflation through Presta Valve

Post by WheezyWheels »

To get some tubeless tyres rise up out of the wheel rim bed and seat on some rims after first fitting very rapid inflation is needed. I'm looking for a way of attaching my Topeak Tubibooster (cyclinder that can be pre-charged with air & released rapidly) to a Presta valve with its core removed so air can be blasted into the tyre as rapidy as possible without the obstruction of the valve core.
I have worked out that the Presta head on the Tubibooster will just fit onto the external thread of the valve if pushed hard, but it's a very tight fit & I think risks damaging the rubber inset on the valve head as it's not designed to work that way. It's also difficult to remove the valve head after inflation.
What I want is an adaptor that screws onto the EXTERNAL (ie lower) thread of the presta valve to convert it to to a Presta or Schrader valve with its core removed that the Tubibooster can couple to. Anybody know if such an adaptor exists?
I have searched for such an adaptor but no joy. I know that Presta to Schrader adaptors are very commonaly availabe (I have several), but these attach to the thread on the Presta valve core which defeats the object.
Thanks (PS - don't want to open the 'Tubless vs Tubes vs Tubuler' debate! Just wondering if anybody has had the same issue and come up with a solution.)
mattsccm
Posts: 5101
Joined: 28 Nov 2009, 9:44pm

Re: Seating Tubeless Tyres - Rapid inflation through Presta Valve

Post by mattsccm »

If your inflator is made for presta valves then use it. That's how it works. Removing the core of a presta valve makes no difference. Any pump had to fit those threads , thats the whole point. You push them on. Rubber seals are consumables although I have never worn one out.
If that really doesn't appeal why not just use an adaptor? Something like those made for disc time trial wheels or even just the old flexi connector for traditional pumps. I use the later as a handy convertor between different valve types.
What sort of pressure are you sticking in? Unless you have a pressure rel;ase button you will have presuure in the system that makes it harder to remove an inflated tyred. 100psi in my TT tubulars last night took a hard yank. You can get tubes with smooth valve stems but I haven't seen any tubeless valves. Have a look on Aliexpress.You can find anything there.
rareposter
Posts: 1987
Joined: 27 Aug 2014, 2:40pm

Re: Seating Tubeless Tyres - Rapid inflation through Presta Valve

Post by rareposter »

They're designed to inflate with the core in place - the air can get in plenty quick enough to seat a tyre using a compressor or air cylinder.

The general process is inflate to seal the bead against the rim, deflate, remove core, add sealant through the valve, replace core, reinflate.

If the core isn't there, there's nothing to hold the air in!

I suspect that the "adaptor" thing you're looking for is actually a valve core... There's nothing else that would work to attach an air cylinder to!
NickJP
Posts: 797
Joined: 24 Sep 2018, 7:11pm
Location: Canberra, OZ

Re: Seating Tubeless Tyres - Rapid inflation through Presta Valve

Post by NickJP »

I use an Airshot, whose hose screws into the Presta valve stem in place of the valve core. However, sometimes the tyre beads on a new tyre won't seat even with the valve core removed. In that case, I do the initial inflation of the tyre with a tube in it, over-inflate to get the beads to snap into place, then dismount one bead to get the tube out. After that, I find that the Airshot will seat the 2nd bead much more easily.

Easier with a compressor, but I don't have one.
WheezyWheels
Posts: 3
Joined: 30 May 2023, 6:08pm

Re: Seating Tubeless Tyres - Rapid inflation through Presta Valve

Post by WheezyWheels »

Thanks for the replies, all useful stuff. A few quick responses:-
"Why not use an adaptor?" - Because I can't locate one - never used Ali Express but will have a look. Sounds like I could do with the sort of thing that's supplied with the Airshot - I'll have a look & see if I can get just this (as I have already invested in the Tubibooster)
"Removing the valve core make no differance" - I beg to differ, I'm no scientist but I would have thought the obstruction of the presta valve core must slow down the air flow.
"Fit a tube to get the tyre to seat intially" - great idea! I'll add this to my armory of techniques.
Cheers & thanks again.
rareposter
Posts: 1987
Joined: 27 Aug 2014, 2:40pm

Re: Seating Tubeless Tyres - Rapid inflation through Presta Valve

Post by rareposter »

WheezyWheels wrote: 31 May 2023, 9:28am "Removing the valve core make no differance" - I beg to differ, I'm no scientist but I would have thought the obstruction of the presta valve core must slow down the air flow.
Not sufficiently to impact on seating the tyre. I've used compressed air lines, Airshot, and regular track pumps - occasionally on first seating a track pump can be insufficient but the other two work fine.

Look at an Airshot - you can inflate those to 150psi and it'll dump all that air into a tyre within about 3 seconds. The valve core isn't the issue, it's more likely to be poor mounting technique if you're struggling to get them to stay inflated with an Airshot.

Worth checking the rim tape and the rim for any knocks and dents too.
geocycle
Posts: 2177
Joined: 11 Jan 2007, 9:46am

Re: Seating Tubeless Tyres - Rapid inflation through Presta Valve

Post by geocycle »

rareposter wrote: 31 May 2023, 9:51am
Look at an Airshot - you can inflate those to 150psi and it'll dump all that air into a tyre within about 3 seconds. The valve core isn't the issue, it's more likely to be poor mounting technique if you're struggling to get them to stay inflated with an Airshot.

Worth checking the rim tape and the rim for any knocks and dents too.
You might be right that the valve doesn't make a huge difference but I do remove the valve core to give it every possible chance. the cylinder then discharges its 160 psi into the tyre over a few seconds. But, I agree that if the tyre isn't seating its likely something else related to rim and tyre compatibility. I find that fitting it with a tube first for a few days, carefully removing one bead and the tube with the wheel horizontal, adding the tubeless valve, lubing the beads with washing up liquid, and then blasting it works most times. Very satisfying when it pops on the rim, a PITA when it doesn't!
WheezyWheels
Posts: 3
Joined: 30 May 2023, 6:08pm

Re: Seating Tubeless Tyres - Rapid inflation through Presta Valve

Post by WheezyWheels »

Many thanks for the replies. Looks like the Airshot is a great product. Unfortunatly I have already invested in the Topeak Tubibooster - which looks like a very similar product to the Airshot but without the advantage of attaching directly to the presta valve bottom (external) thread. I have contacted Airshot to see if they will sell me just the valve head!
Part of my difficulty I belive is my older, 2016, "Tubless Ready" wheels, which predate more modern wheels which tend to comply with wheel/tyre compability standards. I think my rims are very slightly oversized dia. hence the difficulty getting the tyre bead to 'pop' up out of the rim bed - like was said when this does happen it is very satisfying!
The soapy water is another good trick - but even this did not work the last time I struggled.
Will deffo try the innertube if/when struggling the next time!
Cheers
mattsccm
Posts: 5101
Joined: 28 Nov 2009, 9:44pm

Re: Seating Tubeless Tyres - Rapid inflation through Presta Valve

Post by mattsccm »

If in doubt more tape! I have tublessed all sorts of rims and if they don't seal bung more tape in. I then use a SKS Renncompressor track pump. Great for old fashion track pressures, useless for fast dumps of lots of air but it works .
Airsporter1st
Posts: 784
Joined: 8 Oct 2016, 3:14pm

Re: Seating Tubeless Tyres - Rapid inflation through Presta Valve

Post by Airsporter1st »

Has anyone tried tightening something (e.g. a cargo strap) around the O.D. of the tyre to get it to seat/seal? Its certainly something we used to do successfully with car tyres when having similar trouble.
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