Need compressor fitting for tubeless install
 

Hi,

I mounted a WTB raddler to my front tubeless rim today, and tried using a presta adapter and a shraeder fitting hooked up to a compressor to blow up the tire. Almost no air went in. Is there a special fitting for this?

Dave

Did you remove the presta valve core first? If not, you need to because it will allow a lot more air in.

https://www.topeak.com/global/en/product/1394-TUBIHEAD

This really helps. You can unthread and reinstall valve core under pressure.

The adapter I have for presta to shraeder will only thread onto a valve core, so I can't take the valve out.

Dave

You shouldn’t need to take the valve core out, but if you’re not getting “hardly any air” into the tire, something is wrong on the inflation side.

It could be a number of things, and is probably a combination of things. What kind of compressor is it; how much does it flow; and what is your hosing diameter? Which inflator head are you using?

If you don’t know the answer to those questions, you haven’t thought enough about the situation, and if you had, you had, you wouldn’t be in this situation.

Let us know where you’re at, and we can begin to offer some suggestions, otherwise just buy a Park INF-2, because that’s the best inflator head you can put on any compressor.

Honestly I think the issue is the fitting. The compressor is a 8 gallon Husky single-stage. I had the output set on 80 psi, but only a tiny amount got into the tire. This compressor can run roofing nailers and spray guns, so I'm not concerned about the output.

Dave

Yeah, if you’ve got 8gal of air on hand, you should be able to seat any tire. You might try bumping up the psi to 120psi, but it sounds like you’ve sussed the problem as constriction at the inflator head.

I don’t know why that would be, so I’d check the fitting of the adapter to the valve first, and make sure the valve pin is fully open and not been closed by the threading on of the adapter.

Next, I’d confirm that I was running at least 3/8ths inch hose if not 1/2”, and definitely not chintzy 5/16ths or 1/4”. That’s from the compressor to the inflator head, the obvious “pinch point” for flow rate.

If all looks good there, I’d move to eliminate the adapter by getting a presta compatible inflator head, on the (perhaps outside) chance the adapter is causing the flow restriction by it’s very design. It’s a hack for having the wrong tools in any case, so I’d seek to jettison it and get a proper inflation head that can be fitted directly to the valve. There are several brands, including Prestaflator, but if you’re in this for real and plan to handle your own tire needs, I’d recommend just paying the seemingly absurd money for a Park INF-2. I’ve used a few inflators before Park, and the INF-2 is far and away the best by any standard that matters me to me, not the least of which is ergonomics.

If none of that fixes it, you’re doning something wrong and need to review your technique.

Air gun, if you have one of those for your air compressor just use that. Pop the valve core out and just jam the air gun nozzle right in the hole. Works better than fighting with schrader valve to presta adapters, or just buy the presta inflator attachment

If you take the valve core out, you don't need the adapter. You can press a standard air hose valve against the presta valve without the core inside. It's a bit of a juggling act to put your finger over the hole with one hand and get the valve core ready to install with the other hand, but it works much better than trying to inflate it with the valve installed. The valve just won't allow enough volume to enter the tire, quickly enough to seat the tire.

That’s not true. I’ve got five tubeless wheelsets and over the years fitting many 650b, 700c, road and gravel tires— maybe over a dozen pairs— I’ve never had to remove a valve core to get tires seated.

I’ve used valve stems from American Classic, Easton, Muc-Off, Winspace, and Supacaz, but I can’t imagine valve brand makes a difference, so if anyone is experiencing trouble around this issue, it’s probably due to their inflation equipment.

Do you know if you can use those with an Airshot cannister?

For sure. Plus given the core is removed it works much better.

I do remove the core with the Airshot. But then I lose all the air in the tire when I remove it and have to pump it up again. (The Airshot is just to seat the tubeless tires on the rim)

But with this chuck, you can reseat the core before removal.

Yes - I understand. That's why I asked if it will connect with the Airshot.

I use Jaco Lightning L3-Series for Bike Tires I got off of Amazon with my air compressor. Works with valve removed on presta. Jaco also has one specific for Schrader I use for the car. They are easy tho unscrew and switch. Also got there digital gauge I like.

I do have a charge bottle I’ll use. Take it on trips.

Today I brought the tire to my local REI, and they seated it free of charge. Brought it home, injected 2 oz of sealant, and swirled it around. 3 hours later, most of the air leaked out. The tire is still seated, so I refilled it with air and swirled it around again. Turns out the valve nut was a little loose, hopefully that's the only issue.

Dave

I prefer using this: https://www.topeak.com/global/en/pro...-TUBIBOOSTER-X
Never have an idea

Is it normal to lose 20 psi overnight?

Dave

No. Well may be with latex tubes.

I tightened the valve core also before work. If it loses a lot of pressure again, will probably water test the wheel and see where bubbles come out.

Dave​​​​​​​

It lost more air. The valve core was leaking pretty badly, so I tightened that. There were a few bubbles on the sidewalk, hopefully the sealant will take care of that. Left the house for a few hours, and it held the pressure pretty close to the original 40 psi. Gonna check again tomorrow morning, but it looks like this one is good now. Thanks everyone!

​​​​​​​Dave

Take the wheel back off, put the valve at 6 o'clock, and bounce the wheel off the ground. That splashes the sealant around the base of the valve and usually fixes slight valve leaks.

If the wheel does not hold air at least overnight, you may have a bum tubeless valve, or a tubeless valve with a grommet that is not providing a good seal against the valve stem and/or the rim bed. This may be due to under OR over-tightening the valve nut; the latter deforms the shape of the grommet. You could also try swapping valves or to a different-shaped grommet. My first time setting up tubeless wheels and tires was also a learning experience which required the guidance from my more experience brethren here on BF.

Noob Question re: Tubeless Valves - Bike Forums

Shraeder air chucks open to release air when the body of the Shraeder valve pushes against the nub in the middle of the valve. Some Shraeder chucks do not seem to play well with Shraeder adapters. I solved a similar problem to the one experienced by the OP when I bought a different chuck.
Brent