WHICH 450 UNDERWENT THE MOST
CHANGES FOR 2012?
It should be noted that contrary to public
opinion, all of the 2012 bikes have received more
than BNG (Bold New Graphics) upgrades for 2012.
However, there is a kernel of truth in the rumors,
because some of the bikes have undergone barely
The Kawasaki KX450F is the king of changes
for 2012, but the KTM 350SXF and 450SXF,
Yamaha YZ450F and Honda CRF450 have all
attempted to resolve past issues with thoughtful
(if minimal) changes.
As for the six 2012 450cc motocross bikes in the
MXA shootout, here is a complete accounting of
the mods they underwent for 2012.
Kawasaki KX450F: Here is a list of 2012
KX450F changes: (1) Black rims. ( 2) New plastic.
( 3) A frame that is 4mm narrower at the spars.
( 4) Smaller 1.6-gallon gas tank. ( 5) Adjustable
footpegs (5mm up or down). ( 6) New intake
cam. ( 7) Redesigned box-bridge piston. ( 8)
Thinner upper ring. ( 9) Stiffer clutch springs. ( 10)
Redesigned fuel pump. ( 11) Shorter head pipe and
60mm-shorter muffler. ( 12) Push-button-activated
Launch Control. ( 13) A four-dog gearbox to
replace the old three-dog gearbox, and a 3mm-
longer shift lever to compensate for the adjustable
footpegs. ( 14) 2.8mm-thicker first gear. ( 15) Three
different plug-in ignition maps.
KTM 350SXF: New mapping leaned out the
fuel by 3 percent and advanced the ignition
timing by 2 degrees. The new maps were aided
by a new air boot and velocity stack. To solve the
2011’s electrical issues, the wiring harness was
upgraded with “marine-grade” sheathing and a
rubber bootie on the TPS sensor. Other changes
include revalved forks, a stiffer shock spring,
reinforced rear fender, repositioned rear-brake
master-cylinder O-ring, SKF fork seals, extra inline
fuel filter and Dunlop MX51 tires (front and rear).
KTM 450SXF: The 2012 KTM 450SXF got
Dunlop MX51 tires, a reinforced rear fender, SKF
fork seals and a repositioned rear master-cylinder
O-ring from the 350SXF. But the biggest news is
the 2012 KTM 450SXF’s diaphragm clutch. With
its steel basket, preload adjustment, integrated
primary gear, rubber cushions, small size and
hydraulic operation it is by far the most creative
clutch ever put in a production bike.
Honda CRF450: For 2012, the CRF450’s
Kayaba forks have stiffer fork springs, while the
Kayaba shock rides on a new rising-rate linkage
that not only lowers the rear of the CRF450 by
5mm, but softens the rate across the board. The
final changes to the 2012 CRF were all-new wider
and longer footpegs and Dunlop MX51 tires.
Yamaha YZ450F: Yamaha’s engineers
reprogrammed the ignition and fuel maps,
lengthened the muffler by 42mm (and reduced the
core size by 3mm), used circlips to hold the shift
forks to a stiffer shift bar, added black anodized
rims, spec’ed Dunlop MX51 tires, and revalved the
forks and shock.
Suzuki RM-Z450: Suzuki changed almost
nothing—save for the BNG, seat cover, fuel-pump
cover and engine breather hose.