Aug 30, 2020 at 6:52Aug 30, 2020
jb-K zepmtbcamps's article
May 8, 2018 at 11:16May 8, 2018
THE BALANCE AXIS... tipping "down" the hill, to stay centred.
From what I can see, what's missing in the argument here is the rider's velocity. At near-zero velocity as the rider drops in and begins rapid acceleration, the ground reaction force is indeed perpendicular to the slope, and the rider should stay in a neutral centred position to maintain weight distribution equally between the wheels. As the rider accelerates towards terminal velocity (due either to air friction or the gradual application of brakes), the ground reaction force tips uphill, until it becomes anti-parallel to gravity at terminal velocity (ie when the acceleration is now zero). At terminal velocity, the centre of mass should now be vertically aligned over the centre of balance between then two wheels, assuming near-equal weight distribution between tires is still desired, and that means effectively the rider is now shifted backwards from the neutral position.
May 23, 2012 at 7:07May 23, 2012