The sequence of events happens fast. You burn into
the corner at full speed, slam the brakes on, crank the
front wheel in the direction of the corner and then release
the brakes. The G-forces are confused. The acceleration
into the corner pushes you backwards, the hard braking
pushes you forward (and tries to make the bike stand up)
and releasing the brakes shifts the G-forces inward.
So, what can the rider do to keep the rampant G-forces
First, if he is fast enough, he might be able to catch
the bike by turning the throttle wide open. This realigns
the G-forces rearward with enough force to capture all the
mass in one direction. If, however, he fluffs the throttle,
the bike will wobble out of the corner.
Second, he can throw his leg out to the inside and touch
the ground. By using his inside leg as a tripod, the rider
stops the G-forces that wanted to throw the bike down. A
forceful-enough dab will straighten the bike up and allow
good old-fashioned gravity to counterbalance the G-forces
and negate them.
WHY TOUCHING IS A BAD THING
Are you still with us? Let’s recap. Motorcycles make
their own gravity, right? This means that, foot in or foot
out, as long as you are on two wheels, G-forces travel to
the ground through the center of the tires. This creates
traction at virtually any lean angle. Your leg is like the
balance pole of a tightrope walker. You can stick it out
and pull it in to help keep the G-forces down the center
line of the bike (realizing that if the G-forces vary off the
centerline, the bike will go in that direction, regardless of
what you had in mind).
Now for the coup de grace. If you touch the ground with
your boot, except in the exceptions that prove the rule,
all bets are off. Contacting the earth changes the weight
distribution between the wheels and alters the direction
and location of the G-forces that travel through the motorcycle. In a sense, dragging or dabbing a boot momentarily
causes your two-wheeled vehicle to act like a tricycle.
When you are railing a berm, everything is in balance
(speed, G-forces and lean angle). But, if you touch the
ground with significant weight on your foot, the balance
is ruined. The centerline of the G-forces is thrown inward.
Your body loses its centripetal stability, and the relationship between the two wheels and the ground suddenly
takes on a third partner. Typically, the G-forces of the bike
will shift to the outside of the turn, while the G-force of
your body will shift to the inside. The rear wheel will start
to slide out and the rider will counter this by swinging
his outstretched leg rearward. That weight shift further
changes the G-forces’ delicate arrangement and the bike
will swap. The rider’s leg will trail back by the rear wheel,
and all forward drive will be turned into instability.
Touching the ground with your feet, especially when
your motorcycle is leaned over, injects a completely
different set of formulas into the stability chart of a two-wheeled vehicle.
ALTHOUGH WE HAVE
WARNED YOU NOT TO TOUCH
THE GROUND WITH YOUR
FOOT, IT IS OBVIOUS THAT
EVERY RIDER DOES TAKE THE
OCCASIONAL DAB IN CORNERS.