rods handle the abuse of National
tracks, and the whole system is
a PSF (Pneumatic Spring Fork)
air fork design. Webb prefers the
stock fork lugs, because he
discovered during testing that the
stockers offer slightly more flex
than the wider KYB lugs.
( 3) Shock. The KYB integral
adjuster shock is a mechanical
marvel. The triple adjuster unit
offers the possibility to adjust the
low- and high-speed compression
damping separately, as well as
low- and high-speed rebound.
Low-speed compression (silver
dial), high-speed compression
(blue) and high-speed rebound
(red) are found on the dial at the
top of the shock, while the low-
speed rebound adjustment is done
at the bottom of the shock.
( 4) Radiators. The rigors of
motocross are not kind to paper-
thin aluminum radiators. That’s
why Star Racing re-welds the
stock radiators at every seam,
with backing braces for strength.
A 1.8-bar high-pressure radiator
cap prevents coolant boil-over.
Such modifications aren’t unusual
for a National race bike; what sets
the Star Racing team apart is how
“The beauty of
is that a bike like the
YZ250F can be custom
tailored to Cooper.”