Racing Motor Cycle Adhesion

[Peter Cook 6Participant @petercook6]

Just a bit of curiosity from a non biker. Watching a bit of the Japanese Moto GP race while eating lunch, I was intrigued by the forces that keep those things on the track when cornering. The TV coverage occasionally showed a graphic which gave speed and lean angle. At times the bikes were cornering with 60+ degree lean angles at 80+mph.

I wondered if one of the motorcycle guru’s on here could explain what magic is holding the bike on the track. I couldn’t see any significant aerodynamics adding to the downforce in the same way as four wheel racers do. Instinctively it looked as if they should slide off sideways (as they clearly do when it all goes wrong).

[bernard towersParticipant @bernardtowers37738]

its mostly down to tyre compounds which are different for different parts of the tyre so harder comps in the middle and softer towards the wall. aero is a bit more difficult on a bike because of the lean thing, you need the aero on the straight but if it was the same on the corner the bike would fall over, i suspect  as the bike is leant over the aero is also leaning so doesn’t have the same effect. Now for the experts to come along!

[Peter Cook 6]

On 6 October 2024 at 15:20 Peter Cook 6 Said:

..what magic is holding the bike on the track.

There is a nut on the top of every MotoGP bike that controls how fast it goes. Halfway down that nut are two balls. The size of the balls determines the corner speed.

[Author]

Posts