2010 KTM 450 SX-F SPECIFICATIONS

ENGINE
Engine type: Liquid-cooled, single-cylinder, four-stroke (electric start)
Displacement: 449.3cc
Bore x stroke: 97 x 60.8mm
Compression ratio: 12.5:1
Fuel system: Carburettor
Transmission: Five-speed
Fuel capacity: 8 litres

CHASSIS
Frame type: Double ground central cradle-type frame
Front suspension: Fully-adjustable USD WP 48mm fork
Rear suspension: Fully-adjustable WP PDS shock absorber
Brakes (front / rear): Brembo 260mm disc brake / Brembo 220mm disc brake

DIMENSIONS
Weight (claimed, dry): 104.6 kilograms
Wheelbase: 1475 (+10)mm
Seat Height: 985mm

PURCHASE DETAILS
Price: $11,995
Colour options: Orange
Test bike: KTM Australia
www.ktm.com.au

2010 KTM 250 SX-F SPECIFICATIONS

ENGINE
Engine type: Liquid-cooled, single-cylinder, four-stroke
Displacement: 248.6cc
Bore x stroke: 76 x 54.8mm
Compression ratio: 12.8:1
Fuel system: Carburettor
Transmission: Six-speed
Fuel capacity: 8 litres

CHASSIS
Frame type: Double ground central cradle-type frame
Front suspension: Fully-adjustable USD WP 48mm fork
Rear suspension: Fully-adjustable WP PDS shock absorber
Brakes (front / rear): Brembo 260mm disc brake / Brembo 220mm disc brake

DIMENSIONS:
Weight (claimed, dry): 98 kilograms
Wheelbase: 1475 (+10)mm
Seat Height: 985mm

PURCHASE DETAILS
Price: $10,995
Colour options: Orange
Test bike: KTM Australia
www.ktm.com.au

Magazine test shootout results worldwide are important for manufacturers when launching their sales campaigns each particular year, with the American media ultra important in the grand scheme of things.

So when KTM’s 450 SX-F won Motocross Action’s Open class comparison for 2010, many around the world stood up and took note of what the Austrian manufacturer has to offer for this year.

Combined with the ultra successful 250 SX-F that has enjoyed success on the race track worldwide in the hands of top riders, there’s no doubt that KTM is pushing its Japanese competitors to the extreme.

MotoOnline.com.au was lucky enough to get our hands on the latest and greatest four-stroke Motocross bikes from KTM over the past fortnight, riding a variety of hard pack and sandy tracks around New South Wales to see just how this year’s KTMs stack up.

Both models have revalved suspension settings for the new year, with new fork seals and bushings used to reduce sliding friction according to KTM’s press kit.

There are new triple clamps that are 22mmm instead of 20, featuring patented twin-screw-clamps in a bid to increase the flex characteristics of the ride as well as the overall stability and handling, as you’d expect.

Apart from that, the shared changes are minimal to the chassis, with new Toyo B153 brake pads fitted, a 1.8 bar radiator cap instead of 1.4, new Renthal hand grips, as well as a new airbox design and air filter.

On the 450 you’ll find the big changes, with a newly designed frame having the steering head welded 10mm lower than in 2009, lowering the seat position and fuel tank for better steering thanks to an optimised weight balance.

Engine wise, the 450 SX-F has also enjoyed the major changes, featuring a reinforced piston that’s 0.5mm thicker for better durability and a new carburettor setting for bottom-end to improve the power delivery.

The big change here is the extra gear in the transmission, boosting it from a four-speed gearbox to five – falling in line with the other top bikes available on the market.

As for the 250, no changes were made to the engine for this year, the engine already arguably the most powerful in the Lites class against a hoard of strong opposition.

Some were looking for linkage this year and it was rumoured as always, however that particular component of the motorcycle has been saved for the trick 350 SX-F and the 2011 models that are due for release toward the end of the year.

Also saved for the 350 is fuel-injection, with the current models remaining carburetted, however we’re not exactly certain if the 250 or 450 will be EFI for next year.

As always, when you buy a KTM – 250 or 450 – you won’t be disappointed with the quality of the components that they feature, with quality brands such as WP suspension, black Excel rims, Brembo brakes littered throughout the models.

There’s also the integrated graphics that are within the shrouds, meaning they don’t have a tendency to peel like your regular graphics.

When it comes to KTM’s Open class Motocross weapon, big power and outdoor satisfaction come to mind as soon as you first think of the push-button electric start.

The Austrian manufacturer has a rich history in Motocross both in Australia and abroad, the powerful engine setting smiles off on faces worldwide – some loving it and others blown away by it.

Ryan Marmont puts MotoOnline.com.au's test KTM 250 SX-F through its paces at Appin.

There’s no doubt that the engine of the 450 SX-F is a demon, the upgrade to a five-speed gearbox this year after a few years with four making the motor complete in its search for the complete package.

A snappy throttle response will greet you at the twist of the throttle, no sign of lag despite the lack of EFI, before a broad spread of power comes on strong – a lot stronger than I personally can make the most of.

Even the top pros acknowledge the high power output of the 450 SX-F, more aggressive than its rivals and featuring a power curve that hits hard off the bottom before pulling for a long time up top.

While the power is phenomenal, it’s the finishing touches such as the super-light hydraulic clutch, mega smooth gearbox and awesome sound that really cap off the engine characteristics of the Kato.

This year has seen KTM concentrate on improving the chassis on the 450 immensely, the steering a great improvement without losing any hint of stability.

You can select your line, aim for the rut and sweep through the turn, however flat corners will force you to focus hard as it seriously does turn quickly when you commit.

The KTM's slogan of Ready to Race rings very true when its comes to the 250 and 450 SX-F models.

On corner exit there’s a lot of grip on offer as it tracts to the ground, but you’ll have to dial in the rear shock if you’re going to get on the gas as best you can on the acceleration bumps that form in some cases.

If the track is smooth, hold on for the ride because the tractability is high and the engine has what it takes to impress as soon as you get on the gas hard.

Generally speaking the shock handles bumps well, although at times the front suspension does feel softer than the rear, requiring some refinements on the overall balance of the bike.

As for the Brembo brakes fitted to the KTMs, the front is absolutely the most powerful and consistent on the market, while the rear is touchy and has a tendency to squeak – whether it’s my testing or the factory guys in action who use a lot of rear.

The hand lever for the front brake features great adjustment to fit each individual size, as does the clutch.

The 450 has the benefit of electric start, which ultimately makes life much, much easier when going riding. The only problem is that there’s no kick-starter fitted as a back up. If the starter button malfunctions, chances are your mate will be pushing to help you fire it into life – and I have seen this happen recently.

Get on the gas hard and the KTMs will match the best in their respective classes.

Other features that make the bike easy to work on includes the easy access air filter via the side plate, which makes both checking, cleaning and changing the filter an absolute walk in the park without a need for tools.

Both the 450 and the 250 four-strokes share the same wheelbase and seat height to give a very similar feel ergonomically, which is a flat seat with reasonably tall handlebars that are the Renthal Fat Bars.

The difference is that the extra 6.6 kilos that the 450 has over the 250 makes it handle completely differently overall, with the Lites class bike feeling a lot stiffer in the way it rides overall.

Its handling is a lot more rigid, deflecting off bumps if you’re cruising but absolutely blitzing the track if you push it hard enough to get the suspension working.

My feeling is that the KTM Lites bike is extremely race focussed, possibly harsh for the amateur rider, but rewarding for those who are experienced enough to push it hard, or heavy enough to get the suspension working properly at a lower pace.

The 250 SX-F is sharp in its handling, rewarding to those who can extract the most out of it, whether it be by taking advantage of the engine’s power or handling package.

Marmont is a KTM 250 SX-F Pro Lites class specialist.

Having factory JDR Motorex KTM team rider Ryan Marmont on hand during a day of testing at Appin confirmed my thoughts that the bike suits fast riders, the former Pro Lites MX Nationals Champion feeling right at home on the stock test bike straight away and setting a standard not too far shy of what he could do on his factory bike that same day.

Brembo’s brakes also work a treat on the Lites bike, it also features the same easy access airbox as the 450 and features the trick Excel rims as standard equipment.

What it doesn’t have compared to its “big brother” is an electric starter, however the kick-starter is easy enough to operate on a 250 and it starts without a fuss every time you kick it over.

I mentioned the power above and it’s important to highlight just how broad the spread of power is on tap considering it’s a 250. While the 450 has mega power that you probably won’t be able to take advantage of, every ounce of power counts in the Lites class.

Whether you’re a rider who prefers bottom-end or top-end power you’ll be impressed, as the engine grunts off the turn and then pulls hard as you work your way up through the six-speed gearbox that’s in the 250.

Tighter handling is where the 450 has improved greatly for 2010.

There’s no hint whatsoever of a flat spot in the powerband from initial application to full throttle – acceleration at its best in the Lites class.

The Renthal ’bars are high quality as standard on both models, but you’ll want to upgrade the protection pad as it’s almost as hard as the alloy that it’s designed to be covering!

Overall there’s no doubt that KTM has progressed big time this year with the 450 as the complete package, certainly stepping up to assert the 450 SX-F as the top European Open class bike and putting it to the Japanese like never before.

As for the 250 SX-F, KTM continues to standout with its spectacular engine and race-oriented chassis, making the bike a sure favourite for those who are looking to compete with a bike straight off the showroom floor without the need for mods.

Good news for those in the market right now for a new ride is that the current Katos have been reduced in price by $800, slashing the cost to just $10,995 for the 250 SX-F and $11,995 for the 450 SX-F.

If you’re looking for a Euro twist in your Motocross past time, there’s never been a better time to lay down your hard earned on KTM’s Australian-built contenders. Bring on 2011!