Performance Bikes — March 2018

(Ron) #1

Pullingthefrontbrakeatfulllean


inthewettakesgettingusedto’



WHO IS JEREMY McWILLIAMS?
Ex-250 and 500 GP racer Jezza is also a KTM
development rider, road racer and occasional film star...

JEREMY


McWILLIAMS


I HAVE WHAT SOME bike nuts regard as the
ultimate day job: testing the 1290 Super Duke
R, Super Duke GT, 1190/1290 Adventure and
now the new 790 range. I work with the R&D
team and project leaders at KTM who are
tasked with developing the road bike range
and Customer Racing department where we
develop road bikes, like the RC390, for racing.
Yes, there is a lot of pressure to get it right but
there’s plenty of job satisfaction if the bikes
are well received by the press and owners.
The R&D department does an outstanding
job; every aspect of a bike is evaluated. They
can replicate real road riding on test benches
in their new facility. The department has
grown from about 40 people when I started
to more than 500, with many smaller
departments within it dedicated to data
recording, brakes and wheels, chassis, motor,
electronics, suspension...
Test riders evaluate everything – tyres,
traction control and ABS, chassis, suspension,
handling and brake performance, ergonomics

KTM


  • usually at different proving grounds
    through Europe. We work with the team to
    improve the bikes before they’re approved for
    production. Tyres, for instance, have to pass
    stringent testing in all conditions at every
    lean angle on road, track, wet and dry
    handling courses. How they perform at tip-in,
    how much effort is required, how they react
    to rider input, do they have self-steering
    tendencies or any lift up under brake and
    acceleration? Where one tyre might out-
    perform another in the dry it won’t make the
    final list if it doesn’t perform in all conditions.
    The bikes go through a severe shakedown.
    KTM know how stiff a chassis needs to be,
    and they know how stiff every other chassis
    on the market is, but this doesn’t mean if you
    make one with same lateral and torsional
    stiffness it will react identically to a
    competitor’s. We start with something the
    team know will be in the ballpark then
    change it according to test feedback and data.
    Street bikes probably have as much data
    acquisition hanging off them as a MotoGP
    bike. It takes the engineers days to get
    through all the data from a test.
    When we started with the 1290 Super
    Duke we had about four WP technicians over
    the test cycle. We’d have forks and shocks in
    different lengths, damping and spring rates,
    and we’d ride up to the top of the roughest
    roads and mountains in Spain. I’d be
    hammering the bikes over those
    roads, then back to normal
    road riding, motorways, city
    centres then back to the
    proving ground with dry,
    wet, rough and dynamic
    handling tracks in one
    facility. Then do all the
    tests again until we had
    covered every angle.
    Every time you ride
    a bike in a new


environment something else shows up. We’d
ride two-up with concrete in the tank bags
then go to the track and deck the footpegs out
to find the best suspension settings. The
toughest test isn’t opening the throttle to
maximum while dragging your toes on a
soaking wet track to test traction control – it’s
testing lean angle ABS. Squeezing the front
brake to maximum pressure at maximum
lean angle on a wet track takes a bit of getting
used to. We worked with Bosch at their
facilities in Germany and Japan to perfect the
TC and ABS. KTM were the first company to
come up with the idea for lean angle-sensitive
ABS, and I had the pleasure of testing the
early systems. When they first asked me to be
the guinea pig it was a relief to find it worked
first time and just needed minor adjustments.
The test is to see if the bike can hold a line
without crashing with full brake pressure –
you need to squeeze the brake to about 50 bar
pressure. We use no more than 15 bar for an
emergency stop...
Chassis stiffness is complicated, but the
boffins in the design department know where
it needs to be. We have been testing a stiffer
chassis lately for one of the bikes as we
noticed that when we used super-soft slicks
on a track there was room to improve. Flex is
good – we need some at full lean angle to
aleviate chatter. It is easy to produce a chassis
that is too stiff; at maximum lean you feel
every ripple in the surface and the bike is not
pleasant to ride. To find the best solution we
had to beef up one of the current frames to
make it stiffer. We went back and forth a few
times before making a change; the test is
rigorous and it has to work with road tyres in
normal conditions and on the race track.
Every rider in the department, including the
project leaders, then tests the bike, then the
test chassis is measured and a new chassis is
designed to the same lateral and torsional
stiffnesses. And then we repeat the test...
Free download pdf