AI quick summary
- Tyre pressure depends on rider+bike weight, tyre width, and conditions — there is no single correct psi.
- Wider tyres and tubeless setups run lower pressures for more grip, comfort, and often lower rolling resistance.
- Over-inflation feels fast but is harsh and slow on rough roads; under-inflation risks pinch flats.
/ 01
Why pressure matters
Tyre pressure shapes ride quality, grip, rolling resistance, and puncture risk — more than almost any other free adjustment. The right pressure lets the tyre absorb bumps (so you roll over them instead of bouncing off), keeps enough air to avoid pinch flats, and maintains grip. The old 'rock-hard is fastest' idea has been thoroughly disproven on real roads.
/ 02
What sets your pressure
Approximate starting points for a ~70 kg rider on tarmac — go higher if heavier, lower if lighter.
| Tyre width | Approx. road psi | Notes |
|---|---|---|
| 25 mm | 90–100 | Classic road, on narrower rims |
| 28 mm | 75–85 | Modern road default |
| 32 mm | 55–70 | Endurance road / light gravel |
| 40 mm+ | 30–45 | Gravel; tubeless usually lower |
/ 03
Weight, width, and tubeless
Heavier riders need more pressure; lighter riders less. Wider tyres spread the contact patch and run lower pressures for the same comfort and grip. Tubeless setups can drop further still, because there's no tube to pinch — and lower pressures on wide tubeless tyres often roll faster, not slower, because the tyre deforms over bumps instead of bouncing.
/ 04
Over- vs under-inflation
Too high and the tyre bounces off every imperfection — harsh, sketchy in corners, and paradoxically slower on anything but glass-smooth tarmac. Too low and you risk pinch flats (tubed) or a sluggish, vague feel. The sweet spot is the lowest pressure that holds shape and doesn't bottom out on impacts.
/ 05
Adjust for conditions
Drop a few psi in the wet for a bigger contact patch and more grip. Run the front a touch lower than the rear (less weight on it) for better front-end feel. And if you want a precise number, online pressure calculators (Silca, SRAM, tyre makers) take your weight, width, and setup and give a tailored recommendation — a great starting point you can then tweak.
/ SOURCES