For a machine that
really doesn’t look all that changed from the ’09 model, the KTM 450SX-F is adorned
with big-time updates. First, they fit it with a 5-speed transmission and then
proceeded to fine tune areas that are of the most concern to the rider-
suspension and handling. Basically the machine was incredibly sound last year,
it had the button start (and this is huge!), it made very strong power over a
broad range, it was carbureted via a Keihin FCR unit, the suspension was plush
and friendly to a wide scope of pilots and the handling was middle of the road.
For
2010 big effort when into chassis changes, and suspension mods. Here’s a quick
look at the changes:
• The engine
retains the Keihin carburetor, though it has received a leak jet this year. The
goal is smoother power down low.
• A new titanium
header pipe comes fit a very unique canister tagged the HPRS system, its goal
is to reduce noise.
• The steering
head is 10mm lower than the '09; the frame and engine rotate forward lowering
the tank and seating position
• KTM has equipped
the SX-F with their new (and patented) triple clamps. For past few years KTM
has had adjustable (18 or 20) offset clamps. Through testing on the motocross
team they have realized that a 22mm offset enhances stability and improves most
cornering traits of the machine.
• The WP fork,
already improved in ’09 via better lower legs gets new bushings and seals for
less stiction and valving to work with the altered chassis.
• The rear WP
shock was on the receiving end of some dramatic internal changes last year and
for ’10 the damper has been shortened by 4mm.
All
of these changes target cornering traits and a lighter feel through the front
of the machine.
Here’s my feedback
after three weeks of Glen Helen and Piru MX testing:
Power: When the
bike was brand new the juice factor was strong, but not overwhelming. It felt
broad, tractable and meaty. After 5-hours of track time it got stronger. It
seems that KTM fit the 450 with harder rings that require more break-in, but
last longer than last years. Right now it’s in the hunt with any 450 out there,
with the exception of the KX450F. That sucker is gnarly. Love the five-speed,
not so much for moto, but just knowing that I can take it off-road and enjoy a
bigger chunk of real estate than I could with a 4-speed.
But, what sets it
apart from every 450 motocrosser on the market is the button. Quite honestly
when you switch back and forth between machines, kick starting a big 450 feels caveman.
Handling: The fork
is a huge improvement, working very well with the new lower steering head. The
action is very smooth, feeling soft and plush yet it forms up incredibly well
on big hits. Compression adjustments take seconds, as there’s a star adjuster
on the top of the fork. Interestingly enough, we never strayed but one or two
clicks from stock. Perhaps the biggest improvement in the handling comes in cornering
ability and lightness through the front end. The 450SX is easy to maneuver,
feels more planted this year (due to the new steering offset) and grabs a line
and hold its. The linkless rear end mates to a shorter shock, so the whole
machine is lower. Overall the bike feels light, is stable and very easy to
ride.
So, the 2010 KTM
450SX-F is going to be a tough customer in the 450 class. Starting, suspension
and tractable power highlight a machine that will certainly take the honors in
the “most versatile motocrosser” category. How it shakes out against the new
YZF and the other Asian machines on a hardcore motocross track is unknown. But
I wouldn’t bet against it!
