Four-fifths of the popular brands of 450cc motocrossers are virtual clones. Sure, they look and feel somewhat different, but each is based on an aluminum frame with linkage rear suspension holding similar kickstart engines. Close inspection will uncover small differences like the YZ semi-perimeter frame, the Honda Unicam valve train and the coming EFI RM-Z, but none of the Japanese manufacturers is taking a design risk, and many of the so-called “differences” can be attributed to ducking existing Japanese patents as much as to genuine innovation. And then there is the sole major player from Europe: KTM.Say what you may about the Austrian company, but don’t accuse it of playing follow the leader. No linkage for the rear suspension, a steel frame, WP suspension and an engine that’s electric-start only. There isn’t even a place for a kick lever. Despite the long list of things that KTM does differently than its Japanese competitors, the 2008 Katoom feels less “different” that any past KTM model.The current bike has a little more to grip with your knees then past models, and a Renthal 996 bar with a more usual bend appeals to riders new to KTM more than the super-straight bend used in the past. Starting with the new-in-’07 twincam engine, KTM has reached current levels of Japanese engine sophistication. No odd rumbles or vibes, crisp and clean clutch engagement and disengagement and snappy, light-flywheel throttle response. KTM actively searched for these qualities by constructing a lighter crank carrying more of its weight toward the rim of the crank circle. New specs for the exhaust cam, but with the same lift, a revised ignition map and a quieter exhaust are all efforts at increasing low-rpm pull and generating more instant throttle response.The slow-revving, heavy crank feel and the last vestiges of the low-production look of “old-world craftsmanship” credited to European machinery are gone. The difficult-to-define soul or character (or whatever you want to call it) still surrounds the KTM like new-car smell in a dealer showroom: that indefinable something that makes a KTM owner measurably more of a diehard than your average motohead. The sort of owner whom dealers claim embraces everything orange whether it is hard parts or accessories.But Dirt Rider isn’t in the business of measuring cachet. We evaluate performance, and the KTM 450 SX-F has it in abundance. We’ll start with the good stuff. Even when KTM didn’t have engines as polished as this one, it knew how to make extremely effective power. Unleashing the power is as easy as pushing a button. You can trust us; it doesn’t take long to be spoiled by the button. The only reason to stay with kickstarting is to avoid weight and complexity. The E-start KTM weighs in right with the other bikes in the class. There’s no weight penalty for the button. Not one pound. And since KTM deleted the complexity of the kickstart system and has an eight-year history of relatively trouble-free E-start systems, the complexity equation is a wash at best. The only drawback to the design is the need to ride regularly. When it comes to batteries, absence doesn’t make the heart grow fonder or the charge stronger. If you let your bike languish for months, you need to acquire a battery tender, or consider something with an old-fashioned kickstart. Maybe it would be better to use it as an excuse to ride more? Once lit, the engine revs quickly and sounds strong. As always, the hydraulic clutch offers immediate feedback. The pull is reasonable and the engagement smooth if a bit narrower than most cable clutches. Shifting is great and missed shifts are rare. The trans is a four-speed, but as little as you use first, it might as well be a three-speed. We rode some fast tracks and never ran out of gear or felt gaps like we do with some four-speeds.
Compared to past KTM SX-F models, this ’08 has more snap and a bigger hit. Compared to Asian models, the power builds smoothly with energy increasing in an immediate relationship to rpm. The harder you twist, the faster it goes. Something about the relationship between the power, the rear suspension and the chassis geometry just works, and the KTM hooks up and accelerates hard. Sometimes it even carries the front all the way around turns when you aren’t even trying. This isn’t the tear-your-arms-off sort of fast, but there’s plenty of power here for any sane moto person.The chassis is generally well-mannered. The new frame design and shock placement introduced in 2007 is much sturdier than past KTM efforts. Not that frame breakage has been an issue, but under severe loading, the chassis would kick to the side. The ’07 chassis design and ’08 suspension settings eliminate the tendency. There’s nothing new about the chassis for ’08 but the suspension settings, but it still works well. effort at the bar required for direction changes. On any bike it can be difficult to separate the handling from the suspension, but it seems especially true here. Riders who got along with the suspension also found the handling agreeable. Pilots who took issue with the suspension were more likely to find the front end busy.Some riders found little to criticize with the chassis or suspension, while others were never able to come up with a setting that they could call plush. WP declared war on stiction and revised the seal head in the shock, and worked on seal and bushing drag on the tubes and the cartridge in the fork. In addition, the spring rates are up front (0.46 to 0.48 N/mm) and rear (6.6 to 6.9 N/mm), the valving is fine-tuned and the shock has more low-speed compression and less high-speed. The suspension action is actually very good at keeping the wheels following the ground and the bike under control. Some would argue that means the suspension is good. Others would say that rider comfort is the measuring stick by which to judge suspension. The SX-F suspension gives a lot of feedback about track conditions, and you feel it as jolting to your hands. We felt the jarring to the hands at all tracks, but even on a brutally rough day at Glen Helen the bike tracked straight, never swapped and kept the wheels on the ground and driving. We saw the same thing with the 250 SX-F. Riders felt a lot of track, but the lap times were right on the money. Turning is crisp and accurate, with only a light Controlled? Absolutely. Plush? Not for most riders. We could never narrow down the suspension issues, either. It wasn’t all heavy guys or all aggressive riders. Some had issues but other riders the same speed, weight and height disagreed.Much has been made about the fact that the KTM rear suspension has no linkage, but the front is most often criticized. The rear now has a good range of adjustment, plenty of bottoming resistance and good control. After you live with the KTM system, you’ll be reluctant to revert to the maintenance and complexity of a linkage. The KTM has two other flaws. One is a seat that is thinly padded and constructed with soft foam-not a good combo. We have noted a variety of seat density from bike to bike. If you get one with firm, dense and resilient foam, the stock seat is fine. Otherwise, it isn’t that comfortable. Second is that throttle response at small openings can grow fluffy as the engine heats. We are certain the problem lies in accelerator pump settings, but we never found a surefire cure.
These problems loom larger since the rest of the bike is very good. The bike is a pleasure when it comes time to perform routine maintenance. It was clearly built by folks who understand that we don’t all have a factory mechanic. The engine is all but magic in output, character and onnectivity. The brakes are exceptionally powerful and all of the controls are properly placed and nicely humanengineered. Plus, the riding position is remarkably adjustable. In other words, the KTM has a lot to like, and some riders will consider it a complete and proper package. Others will see it as a work in progress until it comes back from a suspension shop.Specifications
Weight (ready to ride, no gas): 235 lb
Seat height: 37.8 in.
Ground clearance: 13.2 in.
Seat-to-footpeg distance: 16.9 in.Whats Hot!
E-start is the way to go
Great components, great controls
Adjustable riding position
Easy-to-perform routine mechanical tasks
Hooks up like it is magnetized to dirtWhats Not!
You call that a seat?
Suspension and especially fork not plushOpinions
As much as I value KTMs as an off-road mount, the ’07 450 SX-F and I never developed an understanding. There was too much power and not enough control. The ’08 is a vast improvement. It was easy to jump on and ride. I’m one who definitely didn’t get along with the suspension, but I know from experience that it can work extremely well. Now that Enduro Engineering and Guts have some seat choices that fix the only other significant drawback the bike has, I’m ready to make room for one in the garage. I love the power, the roomy riding position and handling. I trust the bike in the air and on the ground. I just feel like the KTM beats me up too much in braking bumps. I have faith that I can fix that.
-Karel Kramer/6’1″/210 lb/Novice motocrosserThere are things that I really like about KTMs, like the powerful brakes and that super-consistent hydraulic clutch. They usually make really nice power as well. For 2008 the 450 SX-F got much easier to ride, accelerates better through bumps and grew calm and controlled in deep roller bumps. Those rollers are handled whether they’re down a straight or through a semi-flat sweeper. The main negative point is I feel too much through the suspension, and that makes me tired sooner than it should and erodes my trust in the bike when I’m pushing for good lap times.
-Ryan Orr/5’10″/165 lb/ProThe KTM felt pretty comfortable to me in a surprisingly short time. The power was smooth, but there wasn’t as much hit off the bottom as the Honda or the KX-F. The shifting was fine and the clutch felt great and didn’t fade. The engagement point is narrower than a cable clutch, but I could get used to that. The brakes are better than any production bike I’ve ridden. They’re a little touchier than a Honda, but they’re strong. The suspension felt fine, but the track at I-5MX wasn’t really that rough. It was a little harder to hit a small rut in the turns, but perhaps the sand tires on the packed surface could’ve been part of that. Electric start is definitely a plus. It could save you a lot of time in the event of a stall or an easy fall. I never thought about the fact that Alessi had the starter on his bike. When I watched national races I thought he just always kept the bike running when he tipped over. He would fall and hardly lose any time.
-Billy Payne/5’11″/170 lb/ProI’m sitting here trying to figure out reasons why you’d be looking at the KTM 450 SX-F as your choice in MX weaponry. I’d start with the electric starting because that’s an exclusive feature to this bike right now and every rider likes it as soon as they stop doubting that the starter won’t work. Maybe you just want to stand out from the crowd, but in certain areas with good KTM dealers, I’m sorry, you won’t. There may be those still then who don’t like aluminum frames for some reason or another; the SX-F is the holdout chassis in steel. It feels different than Japanese machinery but no different than any other bike, one on one. And it takes about one day in the saddle and you’ll be right at home. If you like a smoother, slower-revving (on the bottom because this bike rips on the top!) engine character and a lighter feeling and steering chassis, then you should look into this bike. It definitely has the strongest brakes. KTM SX-Fs are as durable as anything and have comparable aftermarket support. When it comes to shootout time, I’m sure the KTM will stand out in a few areas as class leader. Having the total package to win it might be a tough order, especially since it seems the most vanilla bike always has a strong advantage going in. This bike isn’t vanilla.
-Jimmy Lewis/5’10″/185 lb/Vet Pro