THE GREATER THE
TRACTION ON THE REAR
WHEEL, THE GREATER
THE TORQUE REACTION
ON THE FRAME
THE WEIRD WORLD OF TORQUE
Engine torque: You can’t loft your front wheel
without the help of your engine. Without engine torque,
the strongest man in the world couldn’t yank the front
tire of a moving motorcycle more than a few inches. To
wheelie, you need a sharp, powerful burst of acceleration.
To obtain this, it’s best to be at the bottom of your engine’s
torque curve before you twist the throttle.
ISAAC NEWTON AND CHAIN TORQUE
As the engine drives the rear wheel forward, there is
“an equal and opposite” reaction that tries to rotate the
motorcycle backwards—around the rear axle.
It might be hard to imagine what we are telling you, but
think of your motorcycle as a drill. You are drilling into
a thick piece of wood. The drill bit is spinning forward.
Suddenly, the drill bit catches. What happens next? Think
hard. That’s right, the drill motor spins out of your
hands in the opposite direction. That is Newton’s law.
Now, imagine that your rear wheel is the drill bit and
your bike’s frame is the drill motor. When you yank the
throttle on hard, the rear wheel spins, but as it catches
in the dirt, the frame is rotated in the opposite direction
from the spinning rear tire (since the tire is spinning
downward on its front edge, the bike’s frame will spin
upwards on its front edge)—instant wheelie!
Laugh if you want, but the torque reaction between the
chain and rear sprocket is a primary reason why your front
end gets light every time you hit the throttle, and it works
in two ways.
10 EASY CRASHES