The KX250 Experience
When I bought my first KX250, I was often asked if I had any regrets about switching
from a purpose-built woods bike to a motocross bike for woods racing. The answer
was relatively simple, actually: my 2002 KTM 300MXC started gathering dust next to
the KX. But it is a valid question – what did I like better, and why? As with most of
the important issues in life, there is no simple answer. There is no right or wrong.
They were both good, but often in different ways. As much as you may wish me to
provide a definitive solution to the conundrum of which to buy, Japanese
motocross bike or European woods bike, I cannot, because I am not you. What I can
offer is my opinions on how my KX and my KTM performed under various
conditions and rider styles. After reading these thoughts, you may still have
questions. You may still have uncertainty. But such is life, young grasshopper.

General Overview- KTM
I’m in my um-teenth year of KTM ownership, and had I not attempted the KX woods
conversion I would have been satisfied with orange for a good long time. The 300
motor is suitable for just about any skill level and no matter how experienced the
rider, most can adapt their riding style to the low-end grunt that this engine is
known for. There’s no unfriendly hit in the powerband, just smooth power from
bottom to top. With its low-end muscle, climbing up a steep, technical hill can be
accomplished with less use of clutch than your average 2-stroke bike. Bigger-bore
4-strokes may be the kings of smooth power delivery, but the KTM 300 is the
thumper’s closest oil-burning rival.

Since the first two KTM’s I owned were purpose-built woods racers, they came
pretty well set up for hare scrambles and enduros. Suspension on both bikes was
excellent, with the exception of the 43mm forks on my ’02 (a do-it-yourself-revalve
helped a lot). Both KTM’s came with lighting coils and even though the MXC didn't
have an odometer like the EXC, its front wheel could drive a mechanical odometer
by simply attaching an OEM odometer drive (which of course doesn't matter
anymore, because mechanical odometers are mostly history). Fuel capacity was
just over 3 gallons, which was long enough to run a 2+ hour hare scramble without
stopping for fuel. O-ring chains and 18-inch rear wheels were stock, as were
kickstands. All of these things made riding in the woods just a little more enjoyable.

General Overview- KX250
Since it was engineered for motocross, the KX was far from race-ready in the
woods. However, I must diverge from our topic here and mention that no bike – not
a single one – is race-ready out of the crate. Forget what the magazines say about
KTM’s. I’d never race one without a skid plate, hardened wheel spacers, rear rotor
guard, heavy duty inner tubes, metal handguards, and of course a steering
damper. So no matter what bike you get, if you plan on racing it in the woods,
you're going to do some stuff to make it suitable for woods riding.

Now back to our topic. Motocross engineering involves specially tuned engines
that are made for sprinting, basically, and the suspension is tuned for hard
landings. Think of it as the difference between running the 200-meter hurdles and
the 5,000-meter steeplechase. The guys who run those races might look similar in
that they generally have two arms, two legs and usually some cool shoes, but
inside they’re tuned differently. Woods riders need an engine with smoother
power for tight, twisty trails and suspension that soaks up smaller, choppy bumps.  
In stock form the KX250 (or any other motocross bike) was by no means smooth in
the woods. But what it lacked in trail-friendliness could be bought in the
aftermarket. I started with the suspension by sending it to W.E.R. Racing for a
revalve. Softer springs, front and rear, also helped make the ride comfortably
plush. I then added an 11-oz flywheel weight to smooth out the engine. The
toughest part about riding a stock KX250 in the woods was that it wanted –
demanded, actually – nearly constant throttle. Before he switched to an RM250, I
used to give Missouri fast guy Zach Bryant some good-natured ribbing about never
letting the throttle on his RM125 slip under the halfway point (ever), but that's the
way MX bikes must be ridden in order to go fast. Unfortunately, it’s hard to be
smooth when the bike is screaming at 8,000 RPM’s in a tight, first-gear section of
trail filled with loose, baseball-sized rocks. The extra inertia contributed by a
flywheel weight keeps the engine RPM’s from quickly dropping off to next-to-
nothing when you let off the throttle. It also gives more lugging power at lower
RPM’s.

Other necessities for the KX250 were a 3.1-gallon IMS tank and an RK X-ring chain
to replace the non-O-ring chain. Its 19-inch rear wheel aside, in this state the KX
was moderately equivalent in hare scramble readiness to a KTM out of the crate
(the KX would still lack some
enduro-readiness, however).

The KX in the woods was not entirely comparable to my KTM, however. It was a
different beast. While the KX probably generated similar horsepower as the 300’s,
it delivered that power in a distinctive way. Since it was bred as a motocrosser, the
KX liked to be ridden aggressively. It shined when I was on the gas with the rear
wheel spinning. The KX loved to turn, which made it cut through tight, curvy trails
with ease. Stopping power was excellent, with a strong front brake that halted the
bike quickly. At speed, the KX was remarkably stable.

What my KTMs Did That the KX Did Not
If I’m nearing the end of a long, tough enduro, there’s no bike I’d rather have than
a KTM 300. Late in the race, when my energy level was running on empty and the
race organizers saved the roughest, most technical trails for last, the 300 let me
lazy. The KX, on the other hand, did not reward lethargic riders. If I was fatigued,
the KX tired me more. Also, some purpose-built off-road bikes have wide-ratio
transmissions, meaning a higher top speed for those rare occasions when you
need to drag race through a wide-open trail. My 1999 KTM 300EXC and 2003 Gas
Gas 300EC had these transmissions, and I liked them lots. The KTM's have been
using hydraulic clutches for many years, which I feel are superior to cable clutches
in terms of operation. The action is smooth and always feels the same, no matter
how much you heat up the clutch.

What the KX Did That my KTMs Did Not
At a race pace, the KX generally felt more confidence-inspiring, starting with the
front brake. Where my first two KTMs often left me wondering if I’d get stopped in
time, the KX could be late-braked without fear of overshooting a turn, thanks to a
very strong, firm front brake. It also felt more stable at higher speeds. Both KTM’s
were prone to headshake when the throttle was opened up in 5th gear, but not the
KX. The engine had a substantial hit in its powerband, which was useful on bermed
grass tracks. Throw the KX into a berm with a healthy dose of throttle, dump the
clutch and hang on. I was also a little more satisfied with the linkage rear
suspension in terms of tracking, versus the PDS linkage-less shock on the KTMs.

The Conclusion
So which was better? Again, there’s no definitive answer, but here’s what I think:

  • The KTM 300 was a great bike for all abilities, but probably more so for
    beginners and intermediate skill levels. The engine was extremely forgiving
    and the low-end grunt meant less clutch work and less wheel spin. It was also
    simpler (and more economical, sometimes) to set up for riding/racing.
  • Back in the day, aggressive riders may have extracted more out of the KX
    and converted motocross bikes in general. I don’t think it was an accident
    that in the 1990s and 2000s, so many of the top GNCC guys raced motocross
    bikes. Now that manufacturers have developed hybrid bikes like KTM's XC
    line, there seem to be less riders converting motocross bikes into woods
    racers. But for a guy who’s in good physical shape and can ride hard for
    hours at a time, a converted motocross bike has its place in the woods.
  • From a strictly monetary perspective, there's a lot less reason these days to
    convert a motocross bike for woods racing. Any purpose-built KTM will
    probably cost less to make ready for racing. But not always. As I found with
    my two KX250's, a leftover Japanese MX bike, adequately discounted, can
    sometimes be bought and modified for about the same cost as a purpose-
    built KTM. However, if you plan to ride enduros and need lights, then in
    almost every case the MX bike becomes more expensive to convert to
    woods use.

In summary, I liked the KTM 300s because they represented the best value for an
all-around bike. Today's enduro-ready bikes are probably even a better value, if
you need a bike with lights. But if you’re an aggressive rider, in good physical
condition and want to specialize in hare scrambles and GNCC’s, a converted
motocross bike isn't the only option by any means. But in the time before the KTM
XC lineup changed the world, a motocross conversion certainly had its place.
Updated December 2014