In the motocross world, the KTM 350SX-F is forced to
compete against 450s. It will probably never win a national
championship in the U.S., and with Tony Cairoli moving
up to a 450, it probably won’t win any more world MXGP
titles. On top of that, it can’t win motocross shootouts
against 450s, either. Yet, it continues to win amateur races
everywhere. The reasons for this are somewhat humbling.
Pro-level motocrossers prefer 450s because they’re pros.
They’re strong, young and capable of exploiting any possible advantage. A 450 is more powerful and only slightly
heavier, so why not train a little harder and hold on a little
That logic only works for 5 percent of the riding population in the U.S. For everyone else, the 350 has the perfect
amount of power, and that secret is no secret anymore.
That’s why so many riders have swallowed their pride and
downsized to the 350.
For 2017 the biggest single change to the KTM 350SX-F
is one that will eliminate the last reason that many riders were staying away. The new bike has a WP AER 48
fork to replace the 4CS. The AER 48 dispenses with coil
springs in favor of a single air chamber in the left fork leg.
That results in over 3 pounds of weight savings. More
important, the internals of the new fork are completely
redesigned. The damping functions are in the right leg and
basically push more oil through reconfigured valve stacks.
The air side of the fork has a fairly clever balance chamber
that refills itself without the need for a second Schrader
valve. This helps make the fork act more like a traditional
spring. KTM also reconfigured the valving in the WP rear
shock and gave it a softer spring.
Aside from the suspension news, the feature
that lit up KTM forums is the traction control.
On the left side of the handlebar is one but-
ton that allows you to change ignition maps and
another that activates traction control. If you press both
buttons at the same time, you temporarily switch into
launch mode, which is like traction control squared. As
everyone is quick to point out, traction control is banned
by AMA Pro Racing. But, that rule pertains to a technol-
ogy that requires wheel sensors and where the front and
rear wheel speeds are compared. This isn’t that. The KTM
ignition simply watches for rapid increases in rpm and
steps in to even things out. The same feature appeared on
a Husaberg almost 10 years ago, and KTM has probably
been working on it under wraps all this time.
Some of the unchanged parts of the bike are still impressive. The DOHC design uses finger-followers between the
cam and valves, which are partially responsible for a red-line that goes all the way up to 14,000 rpm. It still uses coil
springs for the clutch and is one of only three bikes in the
KTM lineup that doesn’t have the DDS diaphragm-spring
design. It’s an electric-start-only bike (KTM having done
away with the kickstarter three years ago). Last year it got
a lithium battery, which is very light. In fact, the whole bike
is amazing in that department. On the official Dirt Bike
scale it weighs 221 pounds without fuel, which is the same
as the new Kawasaki KX250F, and lighter than the 250s
from Honda, Yamaha and Suzuki.
LIFE BETWEEN CLASSES
Let’s get the obvious out of the way: riding the 350SX-F
is a little like riding a 250 and a little like riding a 450. For
most riders, it’s the best of both worlds. But, it’s not for
everyone. To clearly state the negatives up front, the 350
has a horsepower disadvantage that’s undeniable. If the
distance between the start gate and the first turn is less
than 400 feet, the 350 has just as good a chance as any
450 of getting the holeshot. At that distance it’s all about
traction. Beyond 500 feet or so, horsepower takes
over and the 350 will be help-
less against bigger bikes.
Besides that, whenever
the throttle is absolutely
wide open, a 450 will pull
harder. Now, let’s return
to reality. The amount
of time that a typi-
mystery: KTM is
still the only manufacturer to offer
a 350cc motocross bike.
With a rev
kicks in around
the 350 actu-
ally has a very