MTB tyre pressure guide

Mountain bike tyre pressure is a trade between grip, rolling speed and protecting your rims. The right PSI depends on rider weight, wheel size, casing strength and what the trail throws at you.

Wheel size: 29er vs 27.5

A 29-inch wheel rolls over square hits more easily, so you can run a touch more pressure for the same comfort. 27.5-inch wheels have a shorter contact patch and benefit from 1–2 psi less to keep grip in corners.

Discipline: XC, trail, enduro, downhill

  • XC — light casings, smoother trails. Higher PSI (22–28) for speed.
  • Trail — reinforced casings, mixed terrain. 20–26 psi typical.
  • Enduro — heavy casings or inserts. 18–24 psi with extra grip.
  • Downhill — DH casings and inserts. 22–30 psi to support sidewalls under load.

Starting-point pressures (trail, 29er, tubeless)

Rider weight2.3"2.4"2.6"
60 kg20 / 2219 / 2117 / 19
70 kg22 / 2421 / 2319 / 21
80 kg24 / 2623 / 2521 / 23
90 kg26 / 2825 / 2722 / 25
100 kg28 / 3027 / 2924 / 27

Front / rear PSI for trail riding on a 29er with tubeless setup. Add 1–2 psi for rocky terrain, drop 1–2 for mud.

Terrain adjustments

  • Mud — drop 1–2 psi to maximise the contact patch and let knobs bite.
  • Rocks — add 1–2 psi to reduce rim strikes and pinch flats.
  • Roots and wet roots — bias lower for grip; an insert helps protect the rim.
  • Bike park / DH — heavier casing, inserts, and a few extra psi.

Road or gravel rider?

The RidePressure calculator covers road and gravel setups in detail. MTB pressures here are starting points — fine-tune by feel on your local trails.

Open the bike tyre pressure calculator →