Cornering.
This topic is rather important when riding
a motorcycle, funnily enough. In a car or truck you have at least four
wheels in contact with the road. While the load still makes these
vehicle lean slightly away from the direction of the turn you can still
negotiate the corner when you go in a bit hot. Maybe you run a bit wide
or you start sliding a bit when you over-steer but unless you hit
something very hard with a lot of force you are going to survive
unscathed. This is where motorcycles are different and it is important
to know what is needed to get your favorite ride round that curve.
In the Introduction article, I wrote about
'the science of riding a motorcycle', this is were I get to expand a
little on that piece. So, let me start with the obvious, leaning. As I
mentioned earlier, cars and trucks don't have to lean to get round a
bend. To get round on a bike, snowboard or skis you have to move your
mass as far as you can to the inside of the corner. For a motorcycle,
the reason is simple. You have two wheels inline with each other which
isn't conducive to lateral stability, so if you don't lean into the
corner you'll fall outside the corner. You need to push the mass into
tires which increases friction and weight and this helps to maintain
grip. However, overload the tires or hit a patch where there's less grip
and you'll 'low-side' and pray you stay on the low side because being
flung over the high side is about as much fun as ummm, well something
that's not much fun.
Then there's the suspension. It has to be
working correctly. It soaks up bumps and makes the ride comfortable. You
might think gravity keeps the wheels down to the ground but tires are
synthetic rubber balloons full of air. Air and tires compress and
rebound relatively easily or they would feel wooden, this is what riders
call 'feel'. Suspension has to work with all these factors to keep the
tires planted firmly on the road. It has to be strong enough to keep the
bike up and flexible enough to respond to the smallest ripples and big
bumps without bouncing up and down like a jack hammer. Suspension set up
is usually pretty good from the factory and unless you know what you are
doing it's easy to mess up. I will cover suspension setup in another
article but basically the front and back should be working in unison.
With a friend watching, straddle the seat and stand the bike upright and
sit on the seat, it should only move an inch but the front and back
should drop at the same speed. When you pull your weight off the seat
they should rebound at the same speed. This can be done with the bike
loaded prior to a trip or when riding solo.
Back to the cornering. Gyroscopes are fun
little toys and if you have played with one you know how easily they can
be moved when spinning, much more easily than when they are static.
You use this effect when making turns. Most people do not realize that
they actually steer the bike the opposite way than the turn to make the
bike drop into the corner. If you try to do this manually be careful.
You only have to nudge the bar slightly when riding in a straight line
to feel this effect.
Because bikes are rear wheel drive the
power pushes the bike down the road instead of pulling it. The more
power you apply to the rear the more it wants to overtake the front and
can cause a wheelie to pop up or a power slide can happen. Years ago
back in the dark ages (as long ago as the 80's) most tyres were
cross-(bias-)ply, meaning the internal belts form "x"es in the tire
carcass and tires were hard, GP bikes frames were rigid and GP guys used
to rear wheel steer the brutes. To a lesser extent, this force means the
rear wants to go straight so accelerating slightly in the corner
actually has the effect of making the bike turn tighter. So if you go in
too hot you have to do what you can to scrub speed off using a light
amount of front and a little more rear braking but when you know you are
going to cross center and the corner is still blind be brave and
accelerate a bit. This will unload the suspension and increase wheel
speed making the bike easier to turn and makes the rear want to go
straight which it can't so it tries to turn the corner on a larger
radius than the front making the bike over-steer. 'Push' can help you
get round a tightening bend.
The End.
Remember this. Ride your own ride. Give
the guy in front enough room to ride and give yourself enough room to
react. If you fixate on the guy in front you will follow him WHEREVER he
goes. Hold back and ride the road in front of you not your buddies butt,
that might belong to someone else...Heeheee
