MTB tire pressure by rider weight
All-in weight down the side, tire width across the top, front and rear in the cell. Tubeless on 29 inch wheels at a middle trail setting.
The useful range is narrower than you think — which is why one psi matters here and does not on the road.
Weight down the side, tire width across
All-in weight is you plus the bike plus everything you are carrying — pack, water, tools, pads. On a mountain bike that load is a bigger share of the total than it is on a road bike, so it is worth actually weighing rather than guessing.
Front / rear psi · tubeless · 29 in · middle trail setting
| All-in weight | ||||
|---|---|---|---|---|
Tap a weight and a width to hold both axes.
Get the figure for your exact weight and width
Tubeless, 29 inch, on a middle trail setting. If you are still running tubes on a mountain bike these all go up, and you should read the tube page before you pump.
Mountain bike pressure lives in a narrow band
Notice how little movement there is. Across 100 lb of rider, the 2.1 inch rear only moves 6 psi. That is the whole useful range, and it is why a single psi matters here in a way it does not on the road.
It is also why a pump with a proper low-pressure gauge is worth owning. A floor pump calibrated to 160 psi cannot resolve one psi at twenty, and at these pressures one psi is a real change in how the bike behaves.
Wide tires stop obeying the road rule
Off-road pressure is not the road answer with a discount applied. On the road, what limits how low you can go is impedance — the tire deforming over small, sharp surface texture and losing energy. Keep widening the tire and that stops being the thing that binds first.
What binds instead is the rim hitting the ground and the tire rolling on the rim in a corner. Those are different limits with a different shape, so a mountain bike gets its own curve rather than a multiplier on the road one. Follow a scaled road curve out to a 2.4 inch tire and it will hand you a number in the mid-teens that essentially nobody actually rides.
The front should be softer, and it matters more
The front carries less weight, so it comes out lower — one to two psi under the rear in every cell of the table above. Do not level them up. The front tire is your grip in a corner and your traction on a wet root, and it is the one you will notice first when it is wrong.
If you are only going to tune one end by feel, tune the front.
One psi, then ride the same trail again
Too hard on a mountain bike reads as a bike that skates off line on roots and rocks and hands that are done after an hour. Too soft reads as the tire squirming under you in berms, the rim finding rocks, and burping air in hard corners — that last one is the tire momentarily unsealing from the rim and letting go of a gulp of air.
Whichever it is, change it by 1 psi and ride the same trail again. One, not two: go back up to the table and a 25 lb difference in rider weight is worth 1–2 psi, so moving two at once is the same as pretending you put on 50 lb. It also needs a gauge that can actually resolve one psi — if yours cannot, that is the thing to fix before the pressure.
Rate the ride in the app and it moves the number toward you without you keeping notes. How many rides that takes is the same here as anywhere else. Your trails are not our trails, and the last few psi were always going to be yours.