Quote:
Originally Posted by daktulos
I disagree, the centrifugal force wants to push the bike back upright ...
The difference in the circumference between the inner and outer edge of the contact patch will cause the bike to turn in an arc. This causes a centripetal force through the contact patch, but because the centrifugal force is through the CoG, it will cause the bike to tilt back upright. But, this potential rotation is exactly balanced by the downward force due to the CoG no longer being above the contact patch - so you have gravity pulling the bike towards the road and the centrifugal force pulling it upright.
|
Which is exactly the physics behind hanging off the inside of the bike. In doing so you move the COG to the inside so that it continues to act in a plane straight down to the contact patch with the road. With a typical 180 section rear tyre the contact patch is effectively 90mm (or thereabouts) to one side of the centre of the tyre. The 200kg odd of the bike is still above the centre line so by hanging your 90kg or so 180mm off the bike you effectively bring the COG back above the contact patch and brings things back in balance.
Obviously I've generalised a whole lot with the figures there, but hopefully keeping it simple makes it easier to understand. Now you see why skinny little runts like Marquez pretty much have to climb off the bike mid corner where lardy chaps like Crutchlow just have to shift their knee....
To take the principal further this is also why you get above the bike when you are expecting or controlling a slide. Here you want to be using some of the "grip" available to hold the bike down into the corner so that when you lose this grip it wants to pick itself up (the centrifugal force) rather than low siding the tyres out from under you.