MotoOnline editor Alex Gobert flies high with 10-time world champion Stefan Everts, the man behind KTM's 2011 model SX-F range.

The future is here, well that’s what some are saying anyway, and when it’s the likes of 10-time Motocross Grand Prix World Champion Stefan Everts saying it, you’d have to be a fool not to listen.

KTM’s release of a 350cc motocross bike for 2011 may just be the push in that direction that the sport needs, with the arm-stretching 450s currently on the market seemingly proving too much for the average weekend warrior.

In a bike that was unveiled at EICMA 2009 in Italy last November, KTM’s introduction of the 350 SX-F turns a new leaf in the motocross history books – a leaf that Australia’s very own Chad Reed has said may be similar to the two-stroke/four-stroke battle (and, eventually the transition) that commenced over a full decade ago.

On that occasion it was the four-strokes that won the battle in taking over as the leaders of the motocross world, however only time will tell if 350s can extinguish the 450s – a scenario that would only be complete if the Japanese manufacturers joined KTM on the 350cc freight train in an outright conversion of the open class.

For now though, it’s the Austrian manufacturer that’s reaping the rewards of being the first to release a 350, also upgrading its 250 SX-F and 450 SX-F to make the most complete four-stroke motocross range on the market.

While stars such as Cairoli and American talent Mike Alessi have been winning races overseas, not to mention JDR Motorex KTM rookie Tye Simmonds’ standout performance to date in the Pro Open MX Nationals, our first taste of the 350 came just last week at Appin’s Australian launch in New South Wales.

KTM brought out Everts for the launch along with a handful of 250, 350 and 450 SX-F models for us to test and review, making for a super-cool couple of days on the recently constructed race circuit at Macarthur.

Here’s our take on the models in a trio of riding impressions from across the range before a full rundown of the technical details is provided at the bottom of the page.

350 SX-F RIDE IMPRESSION
They have always said bigger is better, however the form of current MX1 World Champion Tony Cairoli on KTM’s brand new 350 SX-F has to be proof that a 350 has more than enough ponies to get the job done at the highest of levels against the 450s in open class competition.

Regular readers of MotoOnline would have caught our first ride impression of the 350 last week just hours after we climbed out of the saddle raving that a new era is upon us.

Highlights of the middleweight weapon that we pointed out in that first test included our approval of the revised ergos package, a fact that we can attest to since nothing stands out or bothers you – it all just fits precisely.

We also noted that the bike features a balanced feel that invites you to gradually work up to speed, urging you to ride it quicker and quicker, a trait that answered everything we threw at it during the launch.

Compared to a 250 or 450, the 350 is exactly what you’d imagine – sitting right in the middle of the pair in every way. It’s faster than a 250, but more nimble in the handling department than a 450 as you’d expect.

A little known fact is that Cairoli had the opportunity to race either the 450 or the 350 in this year’s world title, choosing the smaller capacity machine simply because he could conserve energy better over the duration of a moto and that’s something we can all appreciate.

Again, the engine is more like a 250F with its high-rev ceiling and short stroke, although it’s incredible how the fuel injection assists in giving it a smooth powerband off the bottom before hitting hard and accelerating rapidly in the mid-range.

In places that you’d find the 450 catching you out a little and maybe even losing traction – sections such as mid-corner on hard-pack surfaces and so on – the 350 is absolutely seamless in the way the power is applied.

On the other end of the spectrum, there’s this uphill step-up at Appin directly out of a right-hand turn that requires you to get the corner exactly right to land perfectly on a 250, however a 350 clears it with ease as though you’re on a big-bore.

Make sure you rev that engine hard, as Tye Simmonds explained in our recent ‘How to ride a 350’ coaching column, and you’ll benefit in many circumstances under a variety of track conditions.

You can get away with man handling the 350 as you would on its little brother, while it definitely won’t complain or lag in the engine department if you decide to cruise it around the track like a real deal open class contender.

Revving the engine hard just like a 250F is the best way to make the most of it, and it really is a massive increase of power compared to the 250 SX-F that you’ll experience when on the gas on the 350.

Those who like big-bore power and are heavier will still see the advantages of the 450, while young kids will of course enjoy the ‘effortless’ characteristics of the 250.

The thing is, for your average rider such as myself, who doesn’t get to practice or train much to ride a 450 and is looking for more than a 250 after spending many years on one, the 350 has reinvigorated my outlook on motocross altogether.

Handling wise, the ergos set you over the front-end and really invite you to rail the turns, only slightly lacking in the all-round manoeuvrability of the 250 – a bike that’s super impressive in itself for 2011 as you will read below.

Again, the 350 is more similar to a 250 than a 450 when it comes to handling, meaning you can ride it hard with less possibilities of making a mistake, albeit having the power to pull you out of a mistake if it does happen.

An interesting point is that all three share the same chassis, meaning the wheelbase and seat height is the same on all three models, only differed by the engine capacity and overall weight.

The fact that KTM has introduced linkage in the same year that they’ve launched the 350 has been absolutely genius, giving you that extra bit of confidence to hold the gas open on rough sections and pushing harder into the turns full of braking bumps.

Tractability off the turns is also impressive as the rear suspension soaks acceleration bumps up without a worry, something that’s a particular improvement compared to the previous model SX-Fs.

With Excel rims, Renthal handlebars and grips, the ever-popular Brembo brakes (except that rear still has a tendency to fade if you’re an excessive user!), adjustable front brake and clutch levers (plus the ultra light Brembo hydraulic clutch) and integrated graphics throughout, KTM has brought a very complete motorcycle to the table in just its first attempt of a 350cc.

The 2011 KTM 350 SX-F is the ultimate combination between good handling and a powerful engine.

450 SX-F RIDE IMPRESSION
The 450cc motocrosser in the KTM stable has to be staring down the barrel of a rifle held by the 350, but it will be up to the consumers to decide whether or not it’s time to pull the trigger and knock the higher capacity open class bike off its perch.

It’s no secret that KTM has been working hard to improve its open class contender over the years, and we can safely say that the linkage and all-new chassis that been applied will turn a new leaf for the 450 SX-F in 2011.

The only problem for the 450 is that the 350 has stolen all the limelight, indirectly making the pair competitors for KTM buyers as to what may be best for open class competition.

It wasn’t all that long ago that MotoOnline had the current model 450 out at Appin for our Full Test in March, where we came to the conclusion that while its steering was improved over previous years, getting on the gas out of bumpy turns and handling braking bumps still had room for improvement.

Well, the linkage rear suspension system has absolutely solved those problems as it replaces the former PDS system that KTM had stuck by for such a long time.

In places where you would have been fighting to keep the 2010 450 SX-F under control at speed, you’ll be able to blitz through them on the 2011 model as though you were on a factory bike in comparison.

Despite that, you really can feel the extra three kilograms that the 450 is packing compared to the 350.

Even though the PDS had quite good tractability on hard pack turns as you apply the throttle, the linkage system completes the job even better and offers that extra feel that we’re all looking for on the tricky, slick surfaces.

The balance between the front and rear suspension is greatly improved, a trait that enables you to push harder with more control, enabling you to set up for the turns and place the bike in the exact line you’re aiming for.

I would have liked to see EFI on the 450 though. Not because the carburetor isn’t smooth on throttle application, but for the simple fact that fuel-injected bikes seem to be that touch tamer off the bottom, making them easier to ride.

But hey, if you’re looking for something that’s easier to ride then maybe the 350 is for you!

Those who love big horsepower will absolutely love the engine of the 450 SX-F – twist the throttle and hang on for the ride, only this time you’ll be able to do it without as many frights as the handling package is that much better than previous incarnations.

Like the 350 and 250, the 450 has all the high class components, and German Max Nagl has proven in World Motocross this year that the Austrian-built 450 SX-F is finally up there with the best of the Japanese as he follows in the footsteps of 350-equipped Cairoli.

The 2011 model KTM 450 SX-F is greatly improved with linkage rear suspension, however there's still no sign of EFI.

250 SX-F RIDE IMPRESSION
As the reigning MX2 Motocross World Champion in the hands of Marvin Musquin and a multiple-time winner of many domestic titles around the world, KTM’s 250 SX-F has been the most successful four-stroke motocross in the range since its release.

In motocross circles, the PDS suspension has proven to be the most competitive on the lighter bikes such as the 250F and also the two-stroke SX range, however adding linkage has made a great bike even better for this year.

We commented in our test of the 2010 models that the 250 SX-F is a very rigid ride that tends to deflect off bumps if you hit them on a certain angle, but the new 2011 model with linkage makes the ride that much plusher and more predictable on a variety of surfaces.

You can absolutely rail turns on the new 250 with its weight hitting the scales at under 100 kilos, which effectively puts you in control and allows you to maneuver it as required.

Not only is it good in the steering department on the rutted turns, it has plenty of traction on the flat hard-pack turns, helping you to increase your rolling corner speed as you become 100 percent comfortable.

The compact and thin ergonomics package is a great improvement over its predecessor, another factor that puts the rider in ultimate control and helps you to take advantage of the improved suspension package.

While the linkage and revised chassis has massively improved the handling overall, KTM has added fuel injection to the 250 SX-F, which makes the powerful engine more user-friendly in summary.

In sections where the carbureted 2010 model would snap off the bottom, you’ll now feel a smooth power band at the twist of the lightweight throttle, perhaps taking away some of the ‘buzz’ that was experienced previously.

As usual with EFI bikes, the Austrian 250F is a much tamer beast on initial application off the bottom with no engine delay at all, only then making the transition into the powerhouse that we are used to from KTM as it reaches the mid-range and blasts into the top-end.

One of the most surprising things during the test for me was the six-speed gearbox, which is geared that short as standard that corners where I’d usually be in second gear on Japanese bikes are taken in third – and it has the power to pull it!

If I were to buy a 250 SX-F I’d probably take a tooth or two off the rear sprocket to make it more conventional, as it did take some time to get used to leaving it in third gear on the slower turns, but if I went to second it would simply be geared too short on the exit.

Overall KTM has stepped up once again with what was already an impressive motocross bike, and Musquin is doing a might fine job of defending his championship this season on the all-new 2011 model.

If quality components (yep, all the brand names come standard on the 250 too), exceptional power and superb handling are what you’re looking for in a Lites bike, hit up one of the upcoming KTM Dirt Days and take the SX-F for a spin. You’ll love it.

The addition of EFI on the 2011 KTM 250 SX-F makes it super smooth off the bottom, while linkage completes the bike's handling package.

TECHNICAL DETAILS
The star of the KTM model range is the revolutionary motocross innovation, the 350 SX-F, a bold new concept developed with the fingerprints of Stefan Everts all over it – an innovation by a company that has over 170 world titles to its credit after 55 years in the sport motorcycles game.

As well as the huge development effort that the KTM technicians have applied to the entire model range, these new motorcycles still include some very special innovations. This especially applies to the KTM 350 SX-F.

To give you an idea of the KTM timeline in developing these new bikes, Everts says they first compared a SX-F chassis with linkage in May 2007, before the 350cc engine was finally born in the middle of 2008.

As far as the ergonomics package goes on the new range, this was developed from a clay mould, sculpted to perfection by Everts and the design team for the end result that we have today.

The newly developed frame and chassis components have seen KTM stick with a robot-welded chromoly frame for flex purposes instead of switching to alloy, with the four-stroke motocross bikes featuring new 300 gram lighter aluminium swingarms for their linkage suspension that’s replaced the former PDS system.

There’s also a newly designed sub-frame that’s light and strong, while the cooling system is integrated into the frame.

WP suspension is again back and revised across the range, with CNC machined triple clamps designed to flex and work in cooperation with the 48mm Austrian-made upside-down front forks.

The Excel rims are now silver instead of black to resist wear and tear and save 200 grams per wheel, there are zinc-nickel coated spokes, Brembo brakes and Renthal handlebars and grips are back again to add to the quality list of components.

KTM claims a dry weight of 103.9kg for the 350 SX-F, compared with the 250 SX-F’s 99.9kg and 450 SX-F’s 106.9kg.

Engine-wise, the 350 has an 88mm bore and 57.5mm stroke and is 349.5cc in capacity, featuring a rev ceiling of 13,000rpm. That rev ceiling is possible thanks to titanium valves (intake 36.3mm/exhaust 29.1mm) in combination with DLC coated finger followers.

The crankshaft turns an intermediate gear, which drives the cam chain, acting as a balancer shaft at the same time while holding the water pump. The cam chain tensioner is also hydraulic.

A hydraulic clutch by Brembo is featured, with a ne won-unit clutch basket combined with the primary unit of billet steel guaranteeing unbeatable reliability according to KTM’s press kit.

The 350 SX-F has two oil pumps, as does the 250 SX-F,

The 350 SX-F features electronic fuel injection as well as the linkage, as does the 250 SX-F. Meanwhile, the 450 features linkage, but remains carburetted for another year.

The 350 and 250 both have 42mm throttle bodies in the EFI system, an optional map select switch available in the Power Parts catalogue activating three additional ignition maps. A user setting tool is also available for data logging and to change the maps.

As for the 250 SX-F engine, revisions include new camshafts with new valve timings to improve gas flow due to a new intake channel and a revised exhaust, improving torque.

The generator now is bigger in capacity and runs in oil, remaining kick-started while the 350 and 450 are both standard with electric start. Kits are available to switch all three bikes to either kick or electric start.

Finally, as mentioned the 450 surprisingly remains carburetted with the Keihin FCR 41mm flat slide, KTM stating that it makes the bike more suitable when it comes to participating in a range of disciplines including desert racing and so on.

The clutch has also been refined with a stronger basket, with the five-speed garbox that was introduced on the 2010 model now featuring a slightly closer ratio.

Another notable change is a quieter muffler that’s utilised across the range, while you can’t ignore the slick new bodywork that again rejuvenates the orange contenders.

As you can see, 2011 marks a massive, massive year for KTM!

There's no doubt that the 350 SX-F headlines KTM's 2011 model sport motorcycle range.

LOOKING FOR MORE?
MotoOnline.com.au has had massive coverage from the Australian launch of the 2011 KTM SX-F range, so check out these stories:

First Ride: 2011 KTM 350 SX-F
How to ride a 350 with Tye Simmonds
2011 KTM SX-F Range Launch Videos (includes action video and technical presentation from the launch)

Images: Pixel Pig Photography