B of 'th
ikes eWorld Championship 500cc MX Series
By Alex Hodgkinson
hey ar.e the biggest, meanest dirt bikes in the game - the
. , . weapons used to dispute the World 500cc MX Championship. And while the Japanese offerings in the other
classes are virtual clones of each other. the big-bike class presents a wide variety, with four-strokes varying in capacity from
399cc to 633cc and two-strokes from 363cc to 499cc .
HUSABERG
The Hu saber g pictured here is the full-fledged '99 factory b ike with d igital, rather
tha n analog, ignition. The CD! unit has proved par ticularly susce p tible to heat, how eve r, and, after three DNFs, reig ning 500cc World Cha mpio n Joel Sme ts reverted to
a revised '98 engine for the sixth roun d of the series in Germany. Tests have still
been progressing an d it is still hoped by the factory that the cha m pion w ill use the
new bike aga in before the en d of the yea r. As chief mechanic Ludo Van der Veken
explains, "SEM , the Swedish elec tro nics firm who su p plies th e ignition, can no t
und erstand why we are having p roblems , but the steering system of the ignition
goes haywire when it reaches 120 degrees Celsius (248 degr ees Fahrenheit) ." Clea rly
visible on the bike is the ventilated ignition cover used in dry-wea ther conditions.
The fact that thi s cove r had been manufactured befor e the first race of the season in
France and was alread v in the truck but nev er raced is a clear indi cati on that the
team was well aware the pot ential problems. The '99 engine also features a lighter
crank to tame the savage power of the 600cc Swed ish engi ne. Even toug h guy Smets
tried to use the spare bike , with its heavier crank, again in Austria, and was thrown
down the track in both trai ning sessions .
or
HUSOVARNA
The factory resources are sp lit in two this yea r. Darryll King (on the number-tw o
bik e) leads the team running ou t of Belgiu m und er Jacky Martens, w hile Yves
Dem aria (on the 110 bike) is the top man in Corrad o Maddii's Italian squad . The
Maddii bikes feature a steeper fork an gle - I degr ee - to make the bike turn sha rper
a nd ar e now cast. (At the Beau caire warmup ra ce, th ey were cut and welded.)
Demaria uses a shorter Sachs-Boggi shock, though differen t link ages maintai n the
same wh eelbase as King's bike. While King had retained the 633cc engine, which
has broug ht the Italian factory all of its successes in recen t years, Demaria is now
en _
using a d evelopment 575cc engine, which delive rs less-ha rsh power. A similar effect
~ has been achieved by the Martens team wi th a new exhaust.
36
