Want do you run yours at? I dented a Pacenti TL28 rim with a GC (not Grid) 2.1″ tyres at 30 psi. Got some wider, tougher 27mm internal width rims and changed to a 2.3″ Purgatory Grid, but I’m still worried about going low on the pressure. Don’t want to dent another rim.

I’m fine with the Stans formula which for me works out at 28psi (this is on a Bontrager XR3 2.2″)

Tyre pressure varies massively from person to person.

Rider weight, rider style and typical terrain being the main variations.

I’m about 72kg, ride in the Lakes, not a particularly hard rider but don’t mince either. 26/27ish PSI in the rear. 29″ HT.

The rim has made contact with a few rocks but nothing too harsh.

Try something with a stiffer sidewall, Ive always found Specialized are very flimsy. A Maxxis EXO on the rear may fare better? I always run Maxxis about 30 rear and 25 front, 85kg on a hardtail.

Agree with the sidewall point, going from the presumably single plys that came as stock to some EXO maxxis’ did wonders for the whole bike. I noticed that on the rear, the threshold between punctures and intolerably bumpy ride is very small though- really only a couple of PSI either way and your day is ruined.

66KG, 28PSI, 26″, fairly unforgiving rider, fairly harsh frame IMO.

I’m 90kg, 2.1 29er maxxis Ignitors on my Cotic. 30 rear, 28 front

And there was me thinking tubeless would mean I ran at lower pressures – currently run 26/28 front/rear with tubes on 29″ at 86kg.

Tubeless curious. Obviously tempting fate now, but I’ve not had any problems with it…

Grids are pretty stout sidewalls. 24psi on my i23 rear Purg grid.

Pacenti rims are soft – perhaps not a pressure issue, and more of a soft rim issue?

Oh…..err…..I just built up a 29er HT.

Running at my usual 19 psi front 22 psi rear.

Only one ride in so far and no problems.

Butcher front, minion dhf rear Both 2.3. 83kg, superstar 25mm rims.

It depends (what trails, conditions, tyre and riding style).
Really have no idea how people get away with low 20s though.

I’m 66kg, running Nobby Nic 2.25’s at the moment on a carbon HT & I’m 22 rear, 18 front.

I’m probably about 80kg kitted up, riding in the Peak District on a 650b bike. Judging by the replies I think I’ll drop the pressure by a couple of psi and see how it goes. It should add a little bit more comfort too.

I thought the Grid sidewall was meant to be tough, I remember reading a tyre grouptest on Enduro magazine that rated them for puncture protection.

The Grid sidewalls are far stronger than the Control versions that most stock Specialized bikes are shipped with. Grid should be fine to run a lower pressure…

I’m a bit fat but get away with 23 front and 25 rear on my Stanton (based on the gauge on my pump). I run Maxxis Minions.

Back in the days of tubed 2.1″ 26er tyres, I used to run approx 35 psi when I was 13.5st.

Now, 15 years later I’m 14st and run 2.3-2.4″ 29er tyres at 16psi front and 18 psi rear on rims approximately 60% wider.

I run the low 20s for trail centres, but that only a small percentage of my riding.

I only have experience of the ground control grid casing, but it’s only a bit stronger than schwalbe snakeskin IMO. I hear on the more aggro spesh tyres that it’s rather more beefy though.