Last of its kind: DIRT ACTION cuts the final laps on the current incarnation of KTM’s open class weapon
Story by Scott Bishop | Photos by Matt Bernard
The Kato 450 SXF as you know it is the dead man walking of dirtbikes. The moment KTM signed Ryan Dungey in the US, the fate of the tried, true and recently successful carby-fed KTM450 was sealed.
It’s even rumoured that the Dungey replica bike that’s been issued to dealers in the US to meet AMA production rules might find its way to Australia before the season is out and be released as a 2013 model in the winter of 2012.
So it’s with a tinge of sadness that we put the old 450, which has gone from a bit of a brumby in its earlier years to a high refined and respect motocross bike in recent times, through its paces for the final time.
Bugger all! In fact the only new part on the 450 SXF is a newly designed clutch. Instead of the old six-spring tension, the new KTM clutch uses a Belleville washer-activated unit. The clutch tension is activated by one large cup-spaced washer, not the multi-spring system used in traditional engine-cycle clutches. It’s still a hydraulic action but the entire basket, hub and spring system is all new.
KTM also installed a holeshot device from standard — not a deal sealer but it’s a nice touch.
What does it go like?
The big Kato engine is impressive. It makes plenty of power all across the rev range and there’s no need to look at the sticker when you jump on this big girl. It’s a thundering, red-blooded 450 that makes the kind of power that excites any motocross racer.
Does it have more power than the other 450s?
Kawie and KTM would be the kings of the class here. The EFI KX engine possibly surges stronger through the bottom and mid but the modulated feel of the carby on the KTM brings the excitement and plenty of thrills high in the rpm.
But consider this: every production 450 puts out anything from 52 to 55hp, so splitting hairs over that much power is a bit much. Most factory 450s in full race trim pump out about 60hp and team managers will tell you they can easily clear the 60hp mark, but finding a pilot who can hang on and wrestle these things around the track for 30 minutes is the hard part. So most view 60hp as the limit for a usable yet ultra-fast 450cc motocrosser in the hands of a pro.
Why does it still have a carby?
My guess would be that because the engine already makes so much power it wasn’t high on the KTM priority list. Combine that with a few other facts — the 450SX isn’t a huge seller, it’s nearing the end of its development cycle, the 450 EXC already has EFI and information would obviously flow from that bike — and KTM could afford not to rush EFI onto its big orange beast.
How does it handle?
The KTM 450SX is a big motocross bike, there’s no mistaking that. A 450cc bike usually shows up any flaw in the suspension or handling fast as the issues are always compounded by the extra speed and the extra weight. Having said that, the 450SX is a jack-of-all-trades with very agreeable handling manners. It’s not going to turn like a 250, or even like the RMZ450, but it will grab an inside line and hold it.
The bike will track well on rough straights and hold its shape and form. It doesn’t have the highlights that some of the other brands have but it also doesn’t have the low lights, either. I was happy to pound out laps on the 450SX on any surface without many issues.
What could I do to make it better?
Most riders would be happy to put fuel in and numbers on this bike and race it. But if we’re going to get picky here, there’s a couple of things I’d look at before racing: the ergos, which are starting to get a bit dated; bar bend, bar position in the clamps; and even seat height I’d look at just to really get comfortable on it.
Again, the weight on this bike is noticeable. Like the other bikes in the KTM range, you don’t notice the weight while in flowing motion but steering in tight turns and slowing the beast up takes some doing. Fortunately, the stock brakes on the Kato are good but after you feel how light a Honda 450 is, the rest of the 450 pack are a long way behind.
This is a great 450cc motocross bike. The engine is strong, versatile and damn fast. The chassis is rock solid and covers all the bases while the suspension has been massaged well over the years to unify the package. But the writing is on the wall and the bike as we know it, its days are numbered.
Still, its exit comes at just the right time. It’s been a great warrior for KTM but the time has come for a lighter, EFI’d and updated captain of the KTM motocross fleet — and Ryan Dungey is just sorting that out now for you!
Second opinion: Grant Sayers, Clubman
The KTM450SX-F was a great bike. A few adjustments of the bars and levers made it very comfortable. The hydraulic clutch had a really smooth action which was a bonus when I started getting arm pump. The suspension setup was pretty close to how I like it and with a few tweaks I got it working pretty well. It has a pretty soft seat, which was good at first, but by the second day it had started taking its toll on my butt and lower back. The engine felt very strong whether it was chugging in a higher gear or revving it out down one of the many straights at Coona — it felt smooth everywhere. The only problem I had with the bike was stalling it in corners. Not sure whether it was because I’m used to riding fuel-injected bikes, but after bumping up the idle and getting used to it, it wasn’t too bad. Overall, I thought it was a great bike and I would definitely ride it again.
KTM 450 Time Line
Significant bikes in the KTM450SX history.
2002 The first of the 450SX models. Up until this point, KTM produced a 400cc but this was the first of the 450SX range and KTM still offered a 525SX at this time also.
2007 The first major update. New frame, new engine, updated styling and electric start were just some of the headlines from the 2007 450SX. It was released with plenty of fanfare but not without some teething issues. Hub and rear-wheel breakages were an issue at the time.
2011 After a decade of fine-tuning and developing the no-link PDS rear suspension, KTM dumped the setup across their entire SX range and went for a more conventional linkage system.
2012 Is it the end of an era? Can we expect to see an all-new, EFI KTM450SX out for 2013? The answer is yes.