CLAIM DISPUTE

Matt Collins Nik Cook gives some useful tips on tyre pressure in September’s Ask220 [issue 342]. But as an engineer, I’d dispute the claim that an increased contact area increases grip. The friction generated depends on the materials of the tyre and road and the weight. It’s independent of surface area. So, all other factors being equal, reducing tyre pressure won’t give you more grip.

Reducing the skip and bounce will reduce the likelihood of a wet weather skid, though. So it’s still a good idea. Nik Cook says: If it reduces skip and bounce, and therefore the likelihood of a skid, surely grip is improved? I think this just comes down to semantics! But glad to hear Matt found it useful.