JayNYC

This isn't gravel-specific, but not sure where else to put it…

I had my first puncture with a tubeless tire a couple weeks ago. So I pulled out a CO2 cartridge, but when I went to use it I had a problem. The valve that you screw onto the CO2 cartridge screws onto the wheel valve stem. But the rotation caused by screwing it on started turning the wheel stem and then I had a leak from that spot as well.

How do you manage to use CO2 cartridges without getting an additional leak from the valve stem? How do you keep the wheel's stem from rotating when you screw the CO2 valve onto it?

[Sorry if I have terms off in that description – it's a bit confusing given that there are two valves - one on the wheel and one on the CO2 cartridge. Hopefully you get the gist of what I'm trying to describe.]

redlude97

Did the valve core unscrew or the nut causing the entire stem to spin? If you tighten down the nut then that should prevent it from spinning. Same with the valve core. The other option is to get a co2 head that simply presses onto the valve rather screws on

Darth Lefty 

You should have the nut tight enough that doesn't happen, and you can get inflators that don't need to be screwed onto the valve. But also you should be using a pump with tubeless.

Edit - with latex sealant like Caffe or Stan's, you should be using a pump. The Slime brand stuff says it's CO2 compatible, that's nice of them.
https://www.effettomariposa.eu/en/caffelatex-co2/
https://www.slime.com/au/products/bi...ss-sealant.php

JayNYC

The entire casing was turning. I thought the nut was reasonably tight. When it started spinning I tried to tighten it, but it all kept spinning.

Basically clockwise tightening of the CO2 valve caused the wheel stem casing to rotate clockwise. Which had the effect of unscrewing the nut. For that reason I'm thinking you can't use any type of pump or other inflation device that screws on since it will unscrew the nut loosen things and cause a leak.

base2 

My luck with CO2 cartridges has been 50-50 at best. For whatever reason, IME it was a rare day that 1 cartridge = 1 fix. 2 or even 3 cartridges (!) usually got me home, but not always.

Given the amount of atmosphere readily available, I've found I have better luck with standard pumps. Even a slow leak can be easily topped-up many miles down the road & the discovery of a second or 3rd unexpected hole doesn't come at the risk of no more cartridges or long walks to cell coverage.

If your reason for CO2 is grams, a standard pump isn't really appreciably any different than the head & 3 cartridges anyway.

If your reason for cartridges is time, the difference is minutes, at best.

JayNYC

I've had great luck with CO2 cartridges with tubes. They work great. You just have to have the right size for the tube you're riding. (16g for skinny tires, 25g for typical hybrid or gravel tires).

But now I'm starting to realize they may be wrong for tubeless. Between the chemical interactions and the chance of freezing the sealant… I guess I'll be buying a pump (one that doesn't screw on…)

base2 

Oh, no. Don't get me wrong. I really don't think theres anything "wrong" with cartridges. It's just that it's been my experience that if/when there is a problem, a second hole, a pinched tube, a tire bead that didn't seat, a torn casing that it turns out needed to be booted anyway, even though it looked fine, etc... The unexpected becomes a "real" problem pretty quickly when air supply & number of repair attempts is limited.

The associated risk of "real problem" became unacceptable to me when I realized that a pump could just be pumped more with no additional risk of walking home.

No worries, pumps are cheap & carrying one means you'll never flat ever again, ever & thus never need it...but forget it just one time...

Cheers

JayNYC

LOL. If only carrying a pump meant no more flats! But alas I live in NYC. There's a ton of sharp debris around here just waiting to puncture your tires.

I usually carry 2-3 cartridges. Never just one. Perhaps that's why my experience with cartridges is pretty good – I've never really risked running out of them.

86az135i

I have the type that pushes on, i've had no issues.

DrIsotope

Either use stems that have an o-ring under the knurled nut, or put an o-ring on there now. For added protection, a press-on CO2 head, like a PDW Shiny Obect or a Lezyne Trigger Drive is definitely the way to go.

Oh, and when initially installing the stems, either press down on the base or pull up on the threaded portion when tightening the nut. If the stem is rotating at all, it means it's too loose to begin with.

redlude97

Yep, which might be an indicator you are using the wrong type of stem for your wheels. Once installed the stem shouldn't move at all and should only require a finger tightening for it to secure. I swap valve cores all the time which is more torque on the stem than a CO2 adapter without issues

shoota 

This. Don't use the screw on type. They aren't necessary anyway.

JayNYC

Mine do have O-rings.

Good idea about making sure they're properly tight.

As far as press-on or screw-on – I've ordered a pump and will switch to that. (And it's press-on).

chas58

Well, its the same problem when removing/installing the core. If the nut isn't tight enough, stem will spin. They say to "hand tighten" but I give it a little extra with a wrench to make sure its tight.
Its a little better with the stems that have a square seat in the rim, but the round ones spin pretty easy.

and this is good advice:
"Oh, and when initially installing the stems, either press down on the base or pull up on the threaded portion when tightening the nut. If the stem is rotating at all, it means it's too loose to begin with." - @DrIsotope

rosefarts

I’m surprised nobody has mentioned this. Grab the low part of the stem firmly with one hand (two finger pinch) and screw the head on with the other hand.

I do this and it’s plenty of force to keep the valve from turning. It probably wouldn’t work if you’ve got arthritis or only one hand.

wheelsmcgee

No advice, but I have a floor pump that threads on, and occasionally experience the same issue with the tubeless valve stem spinning/loosening the nut. I probably could use a o-ring like DrIsotope suggests...but if I remember to just hold the valve stem in place as I thread in the inflator it’s fine.