[Closed] Tubeless PSI

Roughly - your weight in lbs divide by 7 gives the starting psi. Then add or take away a few to suit for front/rear. Works for me

Lowest I run on a 2.2 or 2.4 is 15psi. No dings. I'm about 144lb/65kg

I started on the same pressures I used to run with tubes, then came down slowly to find the sweet spot. "Too low" didn't fail but I could feel lateral roll while cornering hard that didn't make me feel too confident. In the end I settled exactly on exactly on what Stan's recommend:

Rider Weight in pounds divided by 7 = x
x - 1 = Front tire pressure in PSI
x + 2 = Rear tire pressure in PSI

http://www.notubes.com/help/tirepressure.aspx

I ride all mountain, natural and parks. 2.5 Minion EXOs on Flows. 80kg, so 176lbs, so 24/27psi. Works for me.

Wider rims and/or stiffer tyre casings would let you get away with lower pressures. Best to experiment. It was pretty obvious when I'd gone "too low" while dropping in 2psi increments.

Hmmm, I've read that Stan's recommendation and it's a bit off for me. I'm a bit lighter but if I run any less than 27ish psi I've had issues with the tyre popping off the rim. ZTR Flow and Hans Dampf which should be a solid combo. I will still ding the rim at 30+psi though but for me, with solid tyres, the odd ding isn't such a bad thing. On the other hand, on your lighter tyres a 'ding' may put a hole in the sidewall which is pretty bad news.

Of course, all these measurements rely on my track pump being 100% accurate, which it almost certainly isn't.

Just some musings on the subject. To answer your question, the correct answer is 24.5 psi.

Cheers folks. According to stans rule that should make it 22f and 25r. I'll see how I get on.

My track pump was wildly inaccurate to the point where 30psi on the dial was more like 38psi! I bought myself a digital tyre pressure gauge which makes life much easier now.

I got a flat a few rides back where stans would only seal it when the pressure got to a certain level. It was a 10 mile ride back via singletrack and road. When I got back I was amazed to find just 8psi in it! That being said, I was taking it super easy just in case

y track pump was wildly inaccurate to the point where 30psi on the dial was more like 38psi! I bought myself a digital tyre pressure gauge which makes life much easier now.

yep that's the crux. where did you get your tyre pressure gauge from?

Think it was from chain reaction. A topeak one. Worth every penny

Yeah - you are right. My pressures are all set from 1 track pump that may be wildly out. Its right for me, but it would be good to know what that pressure actually is. [off to CRC website]

Have run HDs on Flow EX as low as 9psi. I am about 65-67kg loaded.

Run it at 14/15 front/rear for local trails which are pretty smooth, but have quite a few jumpy bits. No problems so far.

Bit weird getting used to the sound of the tyre deforming when you start. I used to run them at 45 and 50 psi! It was like riding twin pinballs in comparison.

Run my X king 2.4 at 20psi front and rear. Still pretty firm at that pressure and TBH I could probably go lower.

r8jimbob88 : How accurate is that TopPeak digital guage? I might have to get one.

I reckon the Topeak gauge is pretty accurate. Given its sole purpose is to read air pressure i'd imagine that its been calibrated pretty well.

22psi in the Fat Albert still feels pretty solid (havent actually had chance to ride it yet though!).

I don't think track pump pressures are very accurate below about 40psi. Optimised for road bike pressures of c100psi plus.

I test the tubeless pressures on my Rubber Queens by simulating cornering hard - push the bike into the ground hard at an angle standing next to it and go as low as I can whilst ensuring that the tyre wall doesn't 'fold' or crease. Seems to work for me but not sure if it would work on tyres with tougher sidewalls.