Tyres are your only link to the trail: how volume, pressure and tread decide your grip — and why less pressure often means more control.
"What tyre pressure should I actually run — and why does my rear wheel keep sliding out?" The honest answer: your tyre is the only connection between you and the trail, and most beginners give away grip right here by running too much pressure.
The research is clear: larger tyre volume reduces impact load in technical terrain and even improved performance in measurements, while more pressure brought no independent performance advantage in the tested range.
In plain terms: pumping hard doesn't make you faster — it just makes you rougher. Because every vibration your tyre doesn't soak up increases your muscle activity and fatigues you. This guide shows you how to find your personal pressure within two or three rides — the point where the bike sticks planted to the ground instead of skipping across the trail.
Before playing with pressure, check the basics: is the tread still there, especially the side knobs that grip in corners? Any cracks in the sidewall? Old, hardened rubber compounds lose noticeable grip even if the tread looks fine.
A worn tyre is like worn brake pads — no fine-tuning will help.
Use the gauge to set a moderate starting value — slightly less at the front than the rear, because the front wheel steers and needs grip while the rear carries your weight. Heavier riders and rough terrain need a bit more; lighter riders get away with less.
What matters isn't the perfect number from the start, but that from now on you test systematically instead of guessing.
Ride your test loop at the starting pressure and note how corners and root sections feel. Then lower the pressure in small steps and ride the same loop again.
You'll feel the bike calm down and the tyres "bite" into corners — that's the volume effect: the tyre works as your first suspension stage and swallows the small, fast hits before they reach you.
At some point the effect flips: the tyre feels vague, squirms in corners, or the rim clangs hard on rocks and edges. Then you're too low — raise it slightly again.
Your ideal pressure sits just above this limit: maximum absorption without rim or tyre suffering. With tubeless you can go lower because there's no tube left to pinch.
Record your pressures — for dry trails, wet conditions (slightly less for more grip) and rough terrain (slightly more against bottom-outs). Pressure is your fine-tuning tool for handling, not a set-once fixed value. Pros adjust it for every course — you're allowed to as well.
Stay within the pressure range printed on the tyre sidewall — far too little pressure can let the tyre squirm off the rim, far too much damages it. Test new, lower pressures on familiar, moderate terrain, not on the hardest descent.
And remember: a sudden loss of grip is a typical crash cause, and most MTB injuries happen in exactly that kind of loss of control. A calmly damped bike is active crash prevention.
Do the "chalk test": mark a spot on the tyre sidewall with chalk, ride a rough section and see how deep the tyre has worked. If it barely uses a third of its height, it's too hard.
This makes your tyre's invisible suspension behaviour visible — fine-tuning with photographic proof instead of gut feeling.
As much as needed against bottom-outs, as little as possible for grip and damping. Start moderate, lower in small steps and stop as soon as the rim touches down or the tyre squirms. Run slightly less at the front than the rear. Pumping hard brings no measurable performance — it only costs control.
Usually two causes: you brake too rear-heavy — beginners measurably rely too much on the rear brake — and your pressure is too high, so the tyre builds no contact patch. Bring the front brake into play, lower the pressure moderately and brake on grippy ground instead of loose rubble.
No — in the tested range tyre pressure had no independent performance effect, while high volume at moderate pressure lowered impact load and even improved performance. What really slows you is vibration: it increases your muscle activity and fatigues you. A planted tyre is the faster tyre.
Not necessarily. The tyre is your first suspension stage, and a full-suspension bike doesn't make you measurably faster on XC terrain — it mainly damps vibration and adds comfort. A well-tuned tyre on a hardtail beats a badly set-up full-suspension bike any day.