10 YEARS WORTH OF KTM 450SXF TESTS (2007-2016)



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The core of Motocross Action magazine is its bike tests. We spend a lot of time testing everything as thoroughly as possible to better inform you about the good, the bad and the ugly of modern motocross machines. The same holds true for the R&D departments of every motorcycle manufacturer. There are men who have dedicated their lives to building the best possible bike they can—within the budget, time and patience constraints of corporate bureaucracies. Sometimes they build something wonderful and sometimes—well, you already know what happens when things go sideways.


KTM has been building motocross bikes for decades, but it wasn’t until recently that KTM became a serious contender in American motocross (and more important, on American showroom floors). MXA wanted to go back 10 years and show you the progress that KTM has made in the last decade. All the copy is pulled from the MXA bike tests of each model year. See what we thought back then and how our thoughts have changed over the decade. What follows is the good, the bad and the ugly of 10 years’ worth of KTM 450SXFs.

2007 KTM 450SXF09.06.352007 KTM 450SXF

“This is a great bike—a great bike that is hampered by two corporate decisions: (1) The suspension settings are off the mark. (2) The head pipe is so short that it kills the low-to-mid transition. Both are easily fixable with the judicious application of moolah. Once you change the springs and exhaust, the 2007 KTM 450SFX rocks (and, best of all, it starts without fail).”


(1) Steel frame. Yeah, yeah, yeah, we know that aluminum is a cool frame material, but don’t discount steel. With the proper engineering, it is possible to make a steel frame lighter than an aluminum frame. KTM’s ’07 frame is 2 pounds lighter than its ’06 frame.

(2) Electricity. This is the way it is supposed to be. Many an AMA National point could have been saved if every bike had electric starting. Plus, KTM gives every buyer two batteries.

(3) Brakes. The best front brake in the motocross world. 260mm of pucker power!

(4) Forks. They have potential, but are seriously under-sprung—and not just for the fast or fat. The soft fork springs are very harsh in the mid-stroke and drop into their travel too easily, which makes them feel stiff, but it is a false reading. The simplest trick is to swap out the stock 0.46 kg/mm fork springs for stiffer 0.48s (and lower the oil height by 15mm). If you can’t find 0.48 fork springs, have your local dealer increase the nitrogen pressure in the SXS forks’ bladder from 1.2 bar to 1.8 bar (from 13 psi to 27 psi). This stiffens up the forks enough to make them raceable by faster riders.


(1) Basic black. KTM’s black rims and fork stanchions look flashy on the showroom floor, but after a couple of races on a rocky track, they look like they were modeled after a Dalmatian.

(2) Side panels. KTM took it to heart when we said that KTM’s old trapezoid number plates were just like not having a number plate at all. So, the new side panels aren’t number plates. The numbers go on the airbox lid.

(3) Four-speed. We liked KTM’s four-speed, but we only race our test bikes. If we used them for desert, play, Glamis or offroad riding, we’d want a five-speed. The MXA wrecking crew doesn’t need to take a poll to know that American riders prefer five speeds over four. Five just sounds faster than four.

(4) Lifting. The real challenge of 2007 450SXF ownership is trying to figure out how to put the bike on the stand after a race. There is no place to grab it, save for the scalding-hot exhaust or flexy fender. We either lifted it by the rear wheel or grabbed the muffler with a gloved hand swiftly.

(5) Front fender. MXA test riders always whined about the need for a fender brace on KTM’s previous front fender. No more. For 2007, KTM beefed up the fender with a molded-in brace. Unfortunately, it doesn’t work, and the front fender hits the tire when you land from jumps.

(6) Powerband. The 2007 KTM powerband is strange. The KTM 450SXF is less than stellar from idle to the midrange. It kind of dogs it at low rpm, and then kicks like an army mule higher in the powerband. Every test rider wanted more bottom and a stronger transition into the middle (although we were very thrilled with the top-end). The problem? The stock head pipe is a massive unit.
The diameter is too large, and the overall length is too short to encourage low-end thrust. The aftermarket pipe builders will have a field day building smaller-diameter and longer head pipes for the KTM 450SXF.

2008 KTM 450SXF09.07.132008 KTM 450SXF

“KTM is the Rodney Dangerfield of American motocross. It gets no respect. In sheer numbers, there are fewer KTMs on the starting lines than any of the other ‘Big Five’ brands. In the psyche of American riders, KTMs are offbeat, unusual and different. KTM is rarely the first choice on the consumer’s wish list. It’s fashionable to knock KTM in the USA, but we’d like to offer them kudos instead. The small Austrian factory has managed to build an engine that is the envy of the industry. It makes the most power, the broadest power, the highest-revving power and is incredibly easy to use. Yes, Virginia, KTM still needs help on its suspension settings, but this bike is more like Charles Atlas than Rodney Dangerfield.”


(1) Hydraulic clutch. Every bike should have a hydraulic clutch. It takes the hassle out of fluctuating lever settings.

(2) Fork guards. KTM’s new wraparound fork guards are the most protective in the sport.

(3) Gas cap. Why would KTM put a lock on its gas cap? You have to push a button before you can turnthe cap. Isn’t that like wearing suspenders to hold up your belt?

(4) Electric starter. Every R&D budget for 2009 should include electric starter technology instead of fuel injection. Modern bikes run fine with Keihin carbs, but they don’t always start. The KTM does.

(5) Power. We are talking about a 2-horsepower gain at peak, as much as 3 horsepower at 9000 rpm and an extra horse off idle. This is a 450cc motocross engine that has gained almost 6 horsepower in three years. Yikes! On the dyno, it is the most powerful 450 motocross bike on the showroom floor. Peaking out at 54.3 horsepower, the 2008 KTM 450SXF is 2-horsepower stronger than the CRF450 and four ponies up on the KX450F and YZ450F.


(1) Black. We love black rims and black forks on other people’s bikes, but not on ours. They look like they were blasted by a shotgun after a couple months of racing.

(2) Hot-start lever. The plastic hot-start lever is prone to damage.

(3) Seat. We’ve never felt comfortable with KTM’s foam. Your KTM dealer can get you optional saddles in every size, from thick to thin.

(4) Tires. We used to think it was cool that KTM brought back the discontinued Bridgestone M59/M70 tire combo, but the world has moved on. These are good sneakers, but not great ones.

(5) Four-speed tranny. Do we think that KTM needs a five-speed tranny? We think that KTM needs to go to five speeds to win over a skeptical American public.

(6) Forks. Is the suspension better than last year’s? Maybe and maybe not. The stiffer springs are a big plus, but the WP engineers didn’t complete the renovations. Last year MXA ran the combination of stiffer fork springs and a lower oil height. We found that the stiffer springs held the front end higher in its stroke, while the larger air cavity reduced mid-stroke harshness. To us, it was the logical path to follow. But, WP only bought into half of our equation. In our opinion, WP gave up a golden opportunity to fix its forks. Instead, WP made a series of changes that resulted in zip-squat-zero improvement in the forks.

(7) Shock. KTM’s no-link rear suspension is a public-relations nightmare. Scientifically, it can be proven that the rising rate of a single-sided, link-less shock is identical to that of a revolving link system, but the average consumer doesn’t buy it. Science or not, they believe that the lack of linkage means that the KTM doesn’t have a rising-rate leverage curve. Wrong! The problem is that KTM has made a mess of its link-less rear suspension. KTM has selected bad rising-rate curves (based on the location of the shock) and hinged their success on the Ohlins-designed PDS dual-piston shock design, which probably wasn’t the proper design for KTM’s system. KTM has stubbornly stuck to its guns in the face of an angry mob.

2009 KTM 450SXF450_SX_F_USA2009 KTM 450SXF

“All of its success on the world’s professional racing stages is important to KTM, but what KTM would really like is to be accepted by rank-and-file American motocrossers. They just want a little respect.”


(1) Handling. The KTM 450SXF corners like a caged tiger. There is none of the old-school understeer that used to define Austrian race bikes.

(2) Power. We like this engine. KTM has produced a usable powerband that has three major charms: (a) It is not scary to use. Although the 450SXF is fast and powerful, it doesn’t feel like it because it starts off mellow and build its intensity as it goes. (b) The 2009 KTM 450SXF feels like it revs forever. In truth, it doesn’t rev forever; it just revs at a metered pace that maximizes pulling power up to where the rev limiter kicks in at 11,200 rpm. (c) With 53.9 horsepower and 34.3 foot-pounds of torque, the KTM can claim the most top-end power, the most over-rev, the highest rev limiter and the longest pull.

(3) Plastic frame guards. KTM’s frame guards protect the frame from scratches and include a burn guard for the mid-pipe. The burn guard melted on our bike, but we never got a hot foot.

(4) Compression adjusters. The new dials on top of the forks are easy to turn.

(5) Triple clamps. The adjustable offset triple clamps are now anodized black, while the fork stanchions are no longer black. It is a lighter and more professional look.


(1) Seat height. The KTM 450SXF is too tall. The seat is not plush, and the edges of the seat wear out in short order, causing fraying on the lower edge.

(2) PDS system. It’s no secret that the MXA wrecking crew doesn’t have much faith in the dual-piston WP PDS shock. We don’t think the rising rate of the KTM’s shock layout needs the extra damping assistance of a secondary damping piston. KTM disagrees, but over the years its engineers have been steadily downplaying the effects of the second piston. For 2009 the needle that activates the second piston comes in much later in the stroke and has been increased in diameter from 11.5mm to 14mm (it was originally an 8mm needle when the system was first introduced). Now the second piston comes into play largely as an anti-bottoming device.

(3) Shock. We had shock troubles. Even with the stiff 7.2 shock spring, we had trouble getting the race sag where we wanted it (110mm). This shock is not on the same level as the Yamaha YZ450F rear suspension.

(4) Tires. The very old-school Bridgestone M59/M70 tire combo is getting long in the teeth.

(5) Front brake. Most MXA test riders preferred last year’s incredibly powerful front brake. It is a better front brake for the average rider, but we will miss the works-style power of the older model.

(6) Graphics. What’s with the cartoons hidden in the radiator-wing graphics? There is a freestyle ramp, a 30-second board and a bunch of juvenile graffiti mixed into a jumbled motif. Next year, let’s try to go classy.

(7) Four-speed tranny. No doubt, the four-speed is easier to ride, but the five-speed would be easier to ride fast.

2010 KTM 450SXFKTM-450SXF2010 KTM 450SXF

“For decades KTM suffered from being too ‘European.’ The orange bikes were tall, long and heavy. The suspension was hampered by offbeat WP suspension components and handling that was more push than turn. No more! Over the last three years, KTM has made quantum leaps with the 450SXF. Today, it is a bike with superb handling, a tremendous powerband and downsized ergos. We like to think of it as the ‘Americanization’ of KTM.”


(1) Consumer complaints. Last year the MXA wrecking crew hated the cartoon graphics, tall seat height and four-speed gearbox. For 2010 those issues have all been addressed.

(2) Handling. This bike corners like it’s on rails, is easily adjusted by changing fork height and remains stable in the rough. KTM deserves kudos for lowering the frame. Not only does this make the bike easier to climb aboard, but it has an appreciable impact on making it feel more centered. The KTM 450SXF corners better than many Japanese bikes (only the RM-Z450 can turn sharper).

(3) Sound. Last year the 450SXF made a very quiet 95.4 dB. This year, thanks to the stock resonance chamber, it came in at 93.3 dB. That makes it the quietest 450 motocross bike made.

(4) Power. The 450SXF has a very nice powerband. It produces power that is not scary to use but pulls across a long range. This is a deceptive powerband. It feels slow but goes fast. The mellow low-end makes it easier to use in tight corners and bumps, while the massive gain in the middle gobbles up ground.

(5) Five-speed tranny. Choosing the right gearing on the 2009 four-speed gearbox was always a compromise. For tight tracks the gearing was too tall in second gear, but on fast tracks the gearing could be too short in fourth gear. Plus, the four-speed tranny had large gaps between each gear in order to have the same speed profile as a five-speed. Not so with the 2010 five-speed gearbox. It is a revelation on the 450SXF.

(6) Jetting. This is the first 450SXF to get a leak jet. Leak-jet and fuel-screw adjustments were the only jetting changes we had to make.


(1) Weight. It’s heavier than we would like, but that extra tonnage is offset by the fact that it has an electric starter. As amazing as it may seem, the KTM is actually lighter than the YZ450F, RM-Z450 and KX450F. Only the CRF450 is lighter. And none of them have a battery or electric motor.

(2) Suspension. There is little doubt that KTM’s no-link rear suspension is not accepted by the vast majority of motorcycle consumers. The blame for this falls on KTM’s inability to get its rear suspension to work properly and the ignorance of the consumers. KTM has mishandled the selection of damping, spring rates and shock angles over the last decade. Thankfully, since 2007, KTM has made major improvements to its shock settings. The rear suspension of the KTM is comparable to most linkage bikes. It should be noted that not every bike with linkage is as good as KTM’s linkless system, which illustrates that it is not the system that you use but how you set it up. Is KTM going to switch to a linkage system? If we were betting men, we’d say yes (and would expect that linkage system to appear on the 2011 KTM).

2011 KTM 450SXF10862_450_SX-F_902011 KTM 450SXF

“Unless you’ve been sharing a two-room walk-up in Mumbai with Osama bin Laden, you know that the 2010 KTM 450SXF was the best 450cc motocross bike made last year. Guess what? The 2011 450SXF is better than the 2010 model. This bike is a gem. Why? Because it has the same great brakes, superb handling and incredible powerband as last year in a smaller, shrink-wrapped package—all the good stuff in fancier clothes.”


(1) Handling. Nothing handles as well as a KTM. If you went back about five years, however, the MXA test crew was saying that nothing handled as poorly as a KTM.

(2) Powerband. This is an awesome powerband. It produces the kind of power that offers the benefits of a manageable low-to-mid powerband with an impressive, high-rpm top end. The power is not scary to use, because it pulls across a long range. There is no herky-jerky throttle response like on some fuel-injected 450s. The KTM 450SXF builds power as the rpm increase, which means that if you want to go faster, all you have to do is leave the throttle pegged.

(3) Airbox. No tools needed. All you have to do is pop the side cover to access the Twin Air filter.

(4) Plastic. We think that we could design a more attractive front fender in about 10 seconds, but the rest of the plastic on the bike is very appealing. The cladding design, with panels that overlap the panels behind them, is unique.

(5) Rising-rate linkage. The 2011 KTM 250/350/450SXFs come with rising-rate linkage, while the KTM 125SX, 150SX and 250SX two-strokes stick with a modified no-link PDS system. It is no secret that KTM’s engineers did not want to go to a Japanese-style rising-rate linkage, but they had no choice. Public opinion forced the move to linkage. We like the KTM linkage system. Equally surprising was that the big gain that we expected in the pesky G-out area, where the shock bottoms in high-G situations, was not there.

(6) 450SXF versus 350SXF. Does the new mid-size 2011 KTM 350SXF make the 450SXF obsolete? No—a big, giant, gorilla-in-the-room, unabashed no. Given a choice between the 450SXF and the 350SXF, every MXA test rider chose the 450 over the 350.


(1) Radiator overflow tube. Whenever the radiators spit water out of the overflow, the hot pipe produced a steam cloud. We mounted a longer vent hose and routed it under the engine cases.

(2) Shock preload ring. This is the worst preload ring in history (albeit accessible when compared to the preload rings of the Japanese brands). It’s harder to use than last year’s aluminum ring (last year’s ring will not fit on this year’s shock because the thread pitch has been changed). The all-new nylon preload ring deforms easily, and, for some reason, it is very hard to turn (and at some point impossible to turn). KTM says not to hit it with a hammer and punch, but sometimes we had to—and on more than a few occasions, we wanted to.

(3) Weight. At 242 pounds this KTM 450SXF is heavy. But, with the exception of the CRF450, it is comparable to its blue, green and yellow competition on the scale.

(4) Backfire screen. After we had the backfire screen on our 350SXF fray on its edge and get sucked towards the intake, we switched from the SXF air filter cage (with a wire screen) to the 250SX two-stroke air filter cage (without a screen).

(5) Spokes. When the bike is new, watch the spokes carefully. We’ve never had this much trouble getting the spokes to take a set on a KTM. The rims seem to be weak, as they show flat spots where the rim lock is tightened down

(6) Gas cap. We don’t like the locking gas cap because it is a hassle, and we don’t like the lipless  filler hole because dirt falls into the tank. We cut off the locking tangs on the gas cap to disable the locking device.



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