I’m riding there tomorrow on a 29er. I usually like to run around 30 in the back & 25psi in the front, but I don’t want to have any accidents as 29ers ridden at the wrong Psi can be a right handful.
What does any one else do ? I don’t want to ruin my day.

Depends on the phase of the moon and state of the tide, if there’s a full moon you need to account for the additional solar heating especialy with no cloud cover. And shortly after slack water the extra gravitational pull of 29er wheels can cause issues if run too high that they cant slip to account fo this.

You see this is what I am worried about.
Good thing is Hopton is not far from my house so I can always go home & re-fettle the bike again, before heading back out.
Thanks thisisnotaspoon.

Doesn’t really matter as the wheels will probably explode before and psi induced accidents 😉

I find 25 PSI on the front totally unusable. If you lower it to 24.6 you get infinitely more grip. That’s on 26″ wheels though so it could be totally different on a 29er.

Is there a sheldon brown type calculator for 26″ wheel psi / 29″ wheel psi ?
Grum, no way. I rode my 29er at Dyfi Forest once at 24.8 psi & went over the bars into a lot of rocks.

18.3 if atmospheric pressure <1018mb, otherwise 19.2

thanks xcentric, think we may even be getting a bit of sleet in the Shire tomorrow. Oh god, what to do.

Is there a sheldon brown type calculator for 26″ wheel psi / 29″ wheel psi ?

It’s like gears – the equivalent pressure is 10% harder on a 29er, more air innit, so 24.6 on 26″ wheels is like 22.1 psi, which is probably too soft frankly.

I don’t think I’m going now, I can’t handle all these calculations. What if I fall off or get overtaken by someone on a small wheeled bike.

Have you taken in to account the need for seasonally-adjusted values for the friction coefficient of loam – I mean, we all know what the figure is for wet roots, but that leaf litter can be a tricky.

I had a perfect ride there a while ago, but as my bike came from Germany and the tyre pressures are measured in Bar, I am unable to help.

Pump them up til your bicep is hurting then go ride

we all know what the figure is for wet roots

Little known fact that the coefficient of friction of roots is actualy absolute zero. It’s one of the universal physical constants, like avagadros number, the speed of light in a vaccum, and the sheep:human ratio in Wales.