2013, the bike got most of the same changes and updates
that KTM gave the rest of its bikes. Most striking of all is
the new look. The SX got new bodywork and looks just
like the four-stroke that Ryan Dungey is using to dominate
the National MX scene. Under the plastic, the bike has a
steel frame with linkage rear suspension—that was introduced last year, with a slight increase in weight. The SX
climbed from 209 to 215 pounds without fuel. This year
the bike’s most significant change is in the WP fork and
shock. In the past, America got the same bike as everyone else, despite the outcry for slightly different suspension. For some reason, European riders liked settings that
Americans couldn’t stomach. But that’s changed. The
American version of the 250SX has a shorter shock and a
stiffer fork. That’s a very important development, because,
historically, suspension has held the 250SX back on these
shores. Both continents get new triple clamps and a new
swingarm. The rear axle is larger this year, and there are
changes to the spokes and hub too.
Within the motor, a very big change is the switch to
KTM’s DDS clutch, which uses a single-diaphragm
spring and dampers that cushion impacts to the hub.
The VForce reed valve has a new shape and is now
called the VForce 4. The SX motor still uses a mechanical power valve that opens more gradually than most
other ball-ramp mechanisms. KTM gives each buyer a
parts kit with alternative springs that allow you to
change the speed at which the valve opens and closes.
Other than that, the motor doesn’t have any strikingly
new technology. Fuel injection will have to wait; for now,
the 36mm Keihin PWK carb is still in command.
It’s possible—likely, even—that no two riders will have
exactly the same take on the 250SX. There are two distinct camps in motocross today: those who have ridden
250cc two-strokes and those who haven’t. You might be
hard-pressed to find a rider under the age of 25 who has
been on a two-stroke since he left the mini class. If
you’re one of those riders, you’ll be stunned by the
sheer power of the 250SX. It’s a rocket. The peak power
and even the torque of the KTM are in the same league
as a 450cc four-stroke. The key difference is the powerband. The two-stroke comes on more abruptly and signs
off earlier. That’s a universal two-stroke thing. What sets
the KTM apart from old-world 250cc two-strokes is the
KTM gave the 2013 250SX a number of
changes, including a new Dungey-esque look.