Re: Most dangerous braking situation...(again)

[jlandry@domain.elided (John A. Landry)]

When he stopped taking his medication, strange voices in "Bennett Moe"
<bmoe@domain.elided>'s head said:

>Not to beat a dead horse here, but I still don't get why a rear lockup
>is more dangerous than a front. I would think just the opposite. Here's
>my logic:

On a slightly related subject...

Way back in the mid-80's I took a Motorcycle Safety Foundation rider safety
course.  To sum up what they said regarding motorcycles... if the front
wheel locks up, YOU'RE DEAD!  You have no directional control, no
gyroscopic stabilization and essentially nothing to hold the motorcycle
upright!  If the rear wheel locks up during mostly straight ahead
braking... no problem.  Other than reduced braking ability (as Tom H.
stated, a sliding tire has less friction than a tire just prior to lockup),
a rear tire skid is quite harmless.

To prove their point, first we watched a video showing a motorcycle
equipped with an outrigger to prevent it from flipping or tipping over.
The rider proceeded to demonstrate front wheel lockup.  It was *horribly*
scary looking.  When the front wheel locked, the handlebars would
*violently* whip to one side or the other forcing the motorcycle hard into
one of the outriggers.  The whole motorcycle would sort of bounce rapidly
to an ultimate stop.  Without the outrigger, it's obvious the motorcycle
would have flipped onto its side the instant the front wheel locked up.
Front wheel lockup cannot be safely experienced without a specially
equipped motorcycle... unless you enjoy picking gravel out of your teeth
and you like the feel of road rash.

Next we went to a large parking lot to practice emergency braking
techniques on our own motorcycles.  In the limited confines of the parking
lot, we practiced straight ahead braking from about 40 mph as quickly as
possible, letting the rear wheel lock completely up.  The instructors would
gauge performance by measuring the distance required to stop after passing
through a timing gate.  Rear wheel lock up and slide on dry or wet pavement
was no problem... as long as the front wheel remained turning and was under
control.  In a rear wheel slide, the front wheel provides the braking
force.  The key to successful emergency braking on a motorcycle is to
immediately straighten up and apply maximum braking.  This requirement to
straighten upright just as the braking begins has to constantly be on a
rider's mind.  When zipping around a blind corner at 70 mph, what would you
do if you suddenly came upon an object in your path?

Oh... and contrary to popular belief from many non-motorcycle riders, with
a heavy street motorcycle you will not flip tail over end by heavy front
brake application.  The front wheel will lock up long before the rear tire
gets very far off the ground.  I suppose a flip is very possible on light
dirt motorcycles and such... especially when leaning forward in making
jumps, etc.

The dead horse is now really dead!

John L.
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