[net.cycle] steering a single track vehicle

fbr@utastro.UUCP (Frank Ray) (02/10/84)

Here's a tip that may save your neck, particularly on slippery surfaces:

The thing to remember when riding a motorcycle is that the point in space
we think of as the center of mass, when going around a turn, is a function
of where the rider sits on the cycle.  There are three things you can vary
to lessen the bike's angle of lean.  How important this is depends on how
fast you ride, how versatile you are, and the conditions of measured
risk you take regarding travel over funny road surfaces.

(1) Your head, particularly when encased in a helmet, weighs close to 40 pounds.
  Watch the heads of road racers going around; they are as level as possible,
but held to the inside of the machine in the turn. 
(2) Your inside leg can be slightly shifted on the seat to the inside of 
the turn, not so much that it impairs your stability
on the bike, but there's a lot of mass in that leg to help balance the c.g.
(3) The inside knee, if hung a bit to the inside, will help to straighten
the bike up a little.  Road racers use pads on their knees, but
they are riding at the limit and sit much lower than street riders.

These techniques all lessen the need to countersteer, improve the rhythm
and flow of going through turns, make twisty roads more enjoyable, and
give the rider more assurance and confidence to tackle inclement weather,
as well as sand, surprises like oil spills, manhole covers, etc.
Also, if you develop these habits, carrying luggage becomes a great
deal easier; you pack better because you become more aware of the
role of the c.g. in cornering, and you control the relatively tall
position of the luggage mass in every turn, i.e., it becomes manageable,
like a backpack.

One can, of course, do just the opposite, that is, move one's body away
from the turning direction, and countersteer to compensate, and also
lean the cycle more.  Around any given turn, however, at a given speed,
the c.g. must remain invariant.  On nice dry roads, at slow speeds, you
can get away with this, but at speed, it won't work; at a much earlier
point, the machine will slide out from under you.

...!ut-sally!utastro!fbr