Gravel Tyre Pressure Calculator

What tyre pressure should I use for gravel riding?

Gravel tyre pressure is significantly lower than road pressure. For a 75kg rider on 40mm gravel tyres, 35–45 PSI clincher or 23–33 PSI tubeless is a good starting range. Lower pressure increases the tyre contact patch on loose and uneven surfaces, improving traction. Use the calculator with your weight, tyre width, surface type, and tubeless setup for precise recommendations.

How much lower should gravel pressure be than road pressure?

Gravel pressure is typically 20–40% lower than road pressure for the same tyre width. A 40mm gravel tyre runs at 35–45 PSI clincher versus a 28mm road tyre at 70–85 PSI. The much lower pressure is intentional — it allows the tyre to deform around rocks and roots, improving traction and reducing impact transmission to the rider over rough surfaces.

Can I run tubeless too low on gravel?

Yes. Running tubeless pressure too low causes burping — the tyre bead momentarily separates from the rim under hard cornering load, releasing sealant and air. The minimum safe pressure depends on rim internal width, tyre volume, and riding style. Aggressive cornering at high speed requires higher minimum pressure. A general guideline is 18–20 PSI minimum for 40mm+ gravel tyres on a rim with 21mm+ internal width.

Does riding style affect gravel tyre pressure?

Yes significantly. Fast riders on hardpack gravel can run higher pressure (closer to road values) for lower rolling resistance. Technical riders on loose or rocky terrain benefit from lower pressure for traction and comfort. Bikepacking riders carrying heavy loads need slightly higher pressure to support the extra weight. This calculator accounts for riding style — Fast, Comfort, and Technical modes adjust pressure accordingly.

What is the pinch flat risk with gravel tyres?

Pinch flats (also called snake bites) occur when the tube is pinched between the rim and an obstacle under impact. With clincher tyres, staying above 30 PSI on gravel significantly reduces this risk. Below 25 PSI with a tube is very high risk on rocky terrain. Tubeless eliminates pinch flats entirely because there is no tube to pinch, which is why tubeless is strongly recommended for technical gravel riding.

Should I use the same pressure front and rear on gravel?

No — the same 40/60 weight distribution applies on gravel as on road. The rear tyre carries more weight and should run 3–5 PSI higher than the front. Some gravel riders also run the front tyre 3–5 PSI lower than the rear specifically to improve steering feel and front traction on descents. Experiment with small adjustments (2–3 PSI at a time) to find your optimal balance.

How does surface type affect gravel pressure?

Hardpack gravel (compacted dirt roads) allows higher pressure similar to rough tarmac. Loose gravel requires lower pressure for the tyre to grip individual stones. Mud and wet terrain benefit from very low pressure to maximise contact area. Rocky technical terrain also requires lower pressure to absorb impacts. The calculator applies surface-specific adjustments automatically when you select your terrain type.

Is there a universal starting pressure for gravel tyres?

A useful starting point for most riders: take your body weight in kg and divide by 2.5 for the rear tyre in PSI, divide by 3 for the front. For an 80kg rider: rear 32 PSI, front 27 PSI with 40mm tyres. Then adjust up if you feel the tyre squirming in corners (too low) or down if the ride feels harsh and you are losing traction (too high). Always use tubeless-specific lower pressures if running tubeless.