Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/127941
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Testin
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the Fast Freddie wa
otorcycle dynamics are incredIbly complicated. Luckily
for us, so are our brains, and many of us develop a
sense for these dynamics that allows US to understand,
critique and use this information to evaluate and improve the
two-wheeled machine as we exert ever greater control over
these dynamics.
. A select few people, however, through genes or determination or both, can do more. Few have done more than three-time
World Ch"mpion Freddie Spencer.
. For while one must certainly be "Fast" to winWorld Championships, you've got to be smarl, too, and you lu>ve to le"rn to
communicate to others what a motorcycle says to you. Some
nders have their talent buried deep within their souls. Spencer
certainly falls into this category. But as a former student at one
of Spencer's High-Performance riding schools, Tfeel qualified to
say he has excavated this talent in ways very beneficial to his
students. As one would expect, the area of concentration in the
school is riding technique. Since we're all masters of technique
here at Cycle News (that's sarcasm), we decided to ask Spencer
about bike behavior.
Before we hear from the ma ter, these are some of our basic
observations about testing bikes: The first step is learning to feel
what the bike is telling you and to communicate bike behavior
in und~rsta.ndabJe terms. The ne"t step is to relate motorcycle
behaVIOrs to the design characteristics that induce them,
whether these are flaws or those difficult few steps closer to
perfection. The final step is understanding how specific changes
alter the motorcycle's behavior.
Over time, one begins to build a catalog of behaviors. The
more seat time you get, especiaUy time near the performance
envelope of the machine you are riding, the bigger your catalog
Wlll be.l think It'S safe to say Freddie Spencer has a big catalog.
And so, it was with this in mind that we asked Spencer the
simple question: How do you test a motorcycle?
"1 would always pick out the first tllTee things," Spencer
said. "First you have to understand a bike's characteri tics
before you can determine what you like about it, or what you
don't like about it. The first thing 1 would notice is how the
motor responds - as far as where the powerband was, especially
on the two-stroke GP bikes because that would get you in trouble as quick as anything. I would always find the powerQand
and get a feel for how the throttle responds. You do all of this at
a pretty slow speed so you can't get in trouble.
"Th.e second thing, obviously, is to get a feel for th.e brakes,
because that's going to determine where your braking points
are. Usually WIth brakes there are two things: lever feel,
whether it requires more pressure for more braking O{ if it had a
pretty light feel, which I would always build into my bikes.
How much brake you have determines your ability to be able to
trail brake. J never liked the brakes to take a lot of brake pressure, because then I didn't feel like 1 had control over stopping
power. Plus, if it required a lot of brake pressure, when the
brakes did come on that could get you into trouble while trail
braking.
"The third thing is suspension and how much feel and feedback I was getting from the front and the rear. Of course, those
two areas you determine on corner entry and exit. For example,
between the '97 and '98 CBR900RR, J could feel it right out of
the pit area - the sensitivity t1lTough the front was improved
dramatically on the '98 bike vs. the '97 bike, iI1 my opinion.
"You have to quickly determine, before you can feel the
front end, how much information you are getting from the front
is twitchiness, chassis characteristics, or suspension. You have
to do all of that before you can get up to speed and get to the
pomt where you can really feel the tire and how much movement and traction you're getting from the front tire. That's why,
when T would tire test, I would never do it on a bike that was
new and that T didn't have a feel for. The information that
you're getting and may be attributing to a tire problem, may be
actuaUy a chassis or suspension problem. You've got to feel
everything from the inside out: throttle position, engine performance, braking capabilities, tI,en suspension, chassis and then
tires. And if I was testing a new chassis, then I'd put on a set of
tires that 1 knew worked. Absolutely. That way you can't
attribute anything to the tires - if it's suspension or chassis.
"When J c1id the d~velopment on the 250 and the 500 during
the wmter of 84 and mto '85, my whole job, I felt, was to make
tI,e bikes work as clos.ely as pos ible to each other - to take out
the variables. And that's kind of an example of that. That way,
when I was going back and forth, I wanted them to be as close
as possible - as much what was physically possible witl, a 250
and a 500. It's always better to Simplify and take out all the different variables that you can.
ยท'The key to testing, like you guys were doing - bikes back to
back - is to try to