Why do Road Racers Stick Out Their Inside Knee?
(Thanks to Duncan Hardy (duncan@ducati.uk.sun.com) for the bulk of this answer, and to Jobst Brandt (jbrandt@hpl.hp.com) for the effect lean has on the tire performance. • It lets the bike lean less for a given speed. By sliding off the inside of the seat, the rider’s body weight is moved towards the inside of the corner. This means the bike needs less lean for a given speed and turn radius. As ground clearance is often the limiting factor in cornering (particularly at higher speed) this allows the rider to corner at higher speeds. Here’s some nerd info that describes turning geometry: t= arctan [ v^2/(g*R) ] v is your velocity, R is the radius of your turn, g is the gravitational constant. t is the “lean angle.” It’s the angle between • the horizontal, and • a line from the contact patch of your tires through the center of gravity of the bike-rider system. Hanging off and sticking out your knee moves the CG of the system to the inside, while leaving the bike more upright, so you don’t
