Tyre pressure

Key facts

Skill level

1/5

Time

5 min

How often

before every ride

Tools

pump with a gauge, digital pressure gauge

Where to start

For a rider of about 75 kg on 2.4′′ tubeless trail tyres: around 1.5 bar (22 psi) in the front and 1.7 bar (25 psi) in the rear. The rear carries more weight, so it runs a little more.

What changes the number

• Your weight with pack and water: heavier riders need more.
• Tyre casing and width: stiff casings and wider tyres run lower.
• Inner tubes: add air to avoid pinch flats.
• Terrain: sharp rocks want more air, roots and wet ground less.

Read the signs

• Too soft: the tyre folds in corners, you hear the rim hit rocks, sealant burps out.
• Too hard: the bike skips over roots, loses grip and feels harsh.

Change by 0.1 bar at a time on a trail you know, and use the same gauge every time — pumps disagree by more than that.

Related articles

• Tubeless tyres — Tyres that seal directly to the rim with no inner tube, holding liquid sealant that plugs small punctures as you ride. Less weight, fewer flats and more grip at lower pressure.
• Gravel — Long rides on unpaved roads and easy trails on drop-bar bikes with wide tyres. Somewhere between road cycling and mountain biking — and the reason many riders discover dirt.
• Pre-ride check — Five minutes before every ride that catch most mechanicals before they happen: tyres, brakes, axles, bars and the drivetrain, checked in one pass around the bike.
• Tubeless setup — Converting a wheel to tubeless: tape the rim, fit a valve, mount the tyre with sealant and seat it with a burst of air. Forty-five minutes the first time, fifteen once you know it.
• Technical climbing — Getting up steep, rooty or rocky climbs without putting a foot down. It takes the right gear before the hard part, weight over the front and smooth, patient pedalling.
• Rock garden — A section of trail covered in rocks — fixed or loose, round or sharp — with no smooth line through. Momentum, line choice and loose arms are what get you across.