Guides · Pressure

Road bike tyre pressure chart

This chart gives the optimal pressure — in bar — for 25–32 mm road tyres by total system weight (rider + bike + gear). It does not follow the classic 15% drop rule: it minimises the sum of casing-flex losses and surface-impedance losses, which is what the PsiBike model computes.

Optimal pressure is strictly proportional to the load each wheel carries. That is why the chart lists front and rear separately: with the typical 45/55 weight split of a road bike, the rear wheel wants around 20% more than the front.

The chart

Assumptions: tubeless, normal asphalt, a 22 mm internal rim (a 28 mm labelled tyre measures 29.2 mm mounted) and a 45/55 load split.

Each cell shows front / rear in bar. For psi, multiply by 14.5. Cells marked ⚠ are cases where the optimum exceeds the 5 bar hookless ceiling and the value is capped: see the hookless guide for exactly what that costs.

How to adjust these values

• Smooth asphalt: +5%. Worn asphalt: −7%. Cobbles: −12%. Applied on top of the chart value.
• With inner tubes: +6% — a butyl tube adds its own hysteresis. And on a hooked rim, the 5 bar ceiling no longer applies.
• Rim wider than 22 mm: the tyre measures larger and the pressure drops. Each mm of internal width adds ~0.4 mm of tyre — see the rim width guide.
• Bikepacking bags: add their weight to the system; the extra load lands mostly on the rear.

Frequently asked questions

Why does my brand's calculator give a different value?

Most follow the 15% drop rule and compress the front value upwards. Between reasonable methods, expect ±0.2 bar. Differences worth less than 1 W are within the model's noise — and rider position is worth 30–50 W, an order of magnitude more than any pressure choice.

Can I use this chart with inner tubes?

Yes — raise the values by 6%. The butyl tube adds its own hysteresis and shifts the optimum up. On a hooked rim, the 5 bar ceiling does not apply to you.

Do front and rear really need different pressures?

Yes. Matching them is a legacy of old pressure tables, which compressed the front value upwards. Each wheel's loss minimum depends only on the load it carries and the width it measures on your rim.