RE: torsens & 'torque split'

["Lawson, Dave" <dlawson@ball.com>]

> 
> Actually, no. Consider again, locked diff, zero traction at one wheel
> = zero counteractive 
> force = zero torque at the wheel with zero traction. . There can be no
> torque without 
> counteractive force and no counteractive force exists if there is no
> traction. 
...
>  With an open diff no torque is applied to either wheel when one wheel
> has
> no traction, no counteractive force, no torque - hence no motion -
> you're stuck!
> 
Ok, I am on a motorcycle on glare ice, I pop the clutch and give half
throttle and the rear wheel spins. I am going no where, just sitting
there with my spinning rear wheel. I have no motion, but am sitting
above a wheel spinning at a constant velocity. If there is no torque at
my wheel, where is that torque the engine is producing going? And why is
my wheel spinning at a constant speed?  

In the angular world, torque is defined as the time rate of change of
angular momentum. When a wheel is rotating at a constant speed, it's
angular momentum is constant, i.e. the engine torque appiled to the
wheel is equal to the opposing frictional forces associated with the
drivetrain and a spinning tire. So a torque is being applied to that
rear wheel, that is what is making it spin. If I let off the throttle,
no engine torque is applied to the wheel and the wheel slows down.
Because frictional forces are creating a  torque in the opposite
direction of engine torque and slowing the wheel down.

-
Dave