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Tubeless tyre pressure

By Wheats - Posted on 09 May 2013

NB: Originally posted elsewhere on the Global Riders Network and appears via syndication.

Hi folks,
I switched to running tubeless about a year ago and love not getting pinch flats anymore but I seem to have to add air more regularly than when I was running tubes to keep the pressure I want. (By the way my tyres don't go completely flat, they just don't have the pressure I want)

I was just wondering if this is the norm? How often does everyone else add air to their tyres?


[Mod. moved to MTB Gear]


Same thing happens to me. Maybe its jsut more sealant but it holds up fine on the trails. Either way when i was running tubes i would check pressures before every ride so it dosen't really concern me. And it takes a few days and it will drop a few psi but thats about it it dosent really drop anymore after that.

Hope this helps.


I loose about 2 - 5 psi over a week.

My tubeless bike does loose air quicker, but I check the pressure on my tubeless and tubed bikes before every ride.

From my experience, most non-UST tyres even with sealant will slowly leak air. UST tyres will not. That isn't to say you wont loose pressure in a UST tyre but it wont change quickly. I ran some Racing Ralphs for a while and they required a refill every ride. I now have an Ikon that doesn't leak as much as the Ralphs and a UST Crossmark that doesn't leak at all.

Im running a full ust set up with ust tyres and they slow leak.. Its just a tubeless thing i guess, well worth it IMO.

Well i run UST tyres on UST rims and they do not leak at all.

My other bike runs UST tyres on rims set up with stans and they leak a tiny amount.

I also run UST tyres on UST rims and find that I lose about 2-5 psi on average per week however there can be weeks that I don't lose any psi.

I normally run between 40 - 43 psi in my Nobby Nics and Furious Freds.

Some leak, some don't . Can be valves, the amount of sealant , the tyre rim interface, etc etc. some times throwing another 50ml of sans in fixes mine completely, especially if I give it a big shake etc.

Try running your tyres at around 26psi and tell me how much better they feel! Eye-wink
Those pressures are WAY to high!

I have tubeless maxxis on my 29r trance xo
They don't leak! Cross mark is ust but front ignitor is the exo series because they don't have a ust 29r ignitor yet. I run about 23-25 in the front and 26-28 in the rear. You can rub tubeless as low as 12 psi

Some of the reasons your tires could be loosing air is because of all those punctures that you would usually notice with your tube, you don't notice now. The Stan's doesn't seal the hole straight away so your gonna to loose some hair. You also have the problem of "burping" the tire. This is when for a split second the bead separates from the rim and loose some air.

I run tubeless on my mtb and roadie and would get slight air loss. I check my pressures before every ride so it doesn't really matter.

I guess I'll just make it standard practice to check my pressures before each ride.

Listen to the wise words of Gazza...your pressure is WAY too high unless you weigh around the 130kg mark, in which case I would assume you only ride downhill Eye-wink

The recommendation from the Stan's website as a STARTING POINT is your weight in pounds divided by 7 and then +2 for the rear and less 1 for the front. This was based on a 26 inch tyre so I would drop a PSI or two on a 29er if that is what you ride.

I run 22 PSI at the back and 19 PSI on the front.

Your comfort and grip will skyrocket!!!

@ Chitts. You should be careful what you assume when it comes to a riders weight.

Mine leak a little. Depends on how conscientious I was with cleaning the old dried goop from the bead track when changing tyres. Eventually the sealant will fill in the pores and it might drop 1-2 psi per week, not much different to running tubes.

I always check pressures before starting a ride. I once burped a front off the rim on a slow technical section at Manly Dam - was bloody lucky it wasn't further down the descent where speeds would have been much higher. I reckon it must have been 15psi or less.

Interesting formula from the Stan's site. I'm spot on for the front by trial and error, but maybe can afford to lose a few psi from the rear. Does it say how wide a tyre it assumes? I'd have thought that should figure in the calcs.

I run UST tyres and rims, front wheel leaks air and needs a quick check before each ride. The rear has never lost any air and I also have a dent in the rim, so go figure!

As for tyre pressure 25-28 PSI is perfect even over very rocky terrain, I am new to tubeless and love the feel of them I won't go back to running tubes again.

I did find in the Convict 100 that the bike felt a bit floaty on some of the down hill sections however I didn't have any issues with traction.

Got a puncture on the weekend that took a long to time seal and had to stop and pump up the tyre a few times.

On average how long (time or distance) does it normally take for a puncture to seal with sealant and is there anything I can do to help with the sealing process other than continue to ride?

If you can find where the leak is take wheel out and hold wheel so hole is at the bottom of the tyre. If on tyre wall then hold wheel at angle so wall is at bottom and sealant covers hole so air has to push sealant out. Seems to quicken the sealing. Not tried this but some say pump up tyre harder than normal.


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