On the move with KTM

By TMX Archives on 12th Jul 06

Bike Reviews

WITH a massive 13 bike adult range, two brand new models and huge amount of development work undertaken, the 2007 range of KTM SX motocross and EXC enduro machines is undoubtedly the most competitive and complete off-road range ever produced by the Austrian manufacturer. The hugely important 450SX-F flagship motocross model and 250EXC-F enduro machine headline the 2007 line-up, but with the ever-enthusiastic and adventurous team of engineers and designers at KTM working incredibly hard to develop an entirely new chassis and style for the entire SX range, as well as making a considerable number of engine developments across the entire model line, there is a lot for KTM to be proud of and for customers to think about.
The big question though is what do these changes mean out on the track and how does the 2007 range shape up?
T+MX News test team of Jonty Edmunds and Ben Johnson found out two weeks ago when they were invited to put the new machines through their paces at KTM's test facility in the Austrian hills. They report back with their first impressions of both the SX and EXC ranges here.
Enduro correspondent Jonty Edmunds tackles the EXC range first, then Ben mulls over the finer points of the SX machines.
THE long-awaited arrival of KTM's 250 EXC-F is the 'highlight' of the Austrian manufacturer's 2007 EXC range, as the high-revving, high performance production version of the Enduro 1 world championship winning machine finally gets included into the eight bike '07 enduro line-up.
Once again delivering the largest range of enduro machines of any manufacturer, with four two-stroke and four four-stroke bikes, KTM's enduro line-up is as extensive as it is impressive and despite the 250 EXC-F being the jewel in KTM's '07 enduro crown, each and every one of the company's other machines have received modifications and updates all intended to keep them at the head of their respective E1, E2 and E3 classes.
With more time spent developing the 250 EXC-F than any other of its '07 EXC models, it is no surprise that 'improvements', rather than extensive changes, are the order of the day for the rest of the range.
Each and every one of the eight EXC models have received numerous engine and chassis updates for the new year. The 48mm USD forks fitted to all enduro machines have a revised 'basic' setting, which is designed to aid comfort and reduces friction. Likewise, the WP PDS shock has also been given new settings. The new SX model swing arm sadly isn't fitted to the EXC range though.
With the entire enduro range keeping the more traditional and familiar KTM styling and not the new angular body work fitted to the SX bikes, the fitting of black Excel rims is the only obvious cosmetic change.
As far as the brakes on the EXC models are concerned, all machines for '07 have wave-shaped discs both front and rear for optimal brake performance.
The 125 has a completely new designed cylinder and cylinder head, which is both extremely compact and a lot lighter than the '06 cylinder, while the 200 EXC receives a new Boyesen reed valve, a new ignition curve and a new 36mm Keihin carburettor. Although changes to both bikes are minimal, with arguably the best 125 on the market, KTM have simply done enough by raising the bar that it set in '06.
The 250cc two-stroke EXC sees its changes focused on the cylinder. Featuring a lighter, stronger and more compact power valve unit, the cylinder, like that of the 125, also features a new water jacket for optimised cooling. The 300, like the 200, features a new V-Force reed block for better throttle response.
All EXC two-stroke EXC models also feature a dual curve ignition which is activated by simply disconnecting one cable that runs into the CDI.
The 400, 450 and 525 EXC-F models are all but the same as the '06 range with the only real change being the fitting of a two-piece clutch cover.
Now fitted with the DOHC SXF inspired motor, the 250 EXC-F is every bit as good as it is new.
The addition of the electric starter unit to the SXF engine is the only external difference between the 2006 and 2007 motors, but internally a number of changes have been made to convert the 250cc motor from motocross to enduro spec.
The fitting of modified cams gives the 250 EXC-F motor a smoother power delivery over the SX-F model, which when added to a modified gearbox results in a smooth and strong power delivery. The ignition is also uprated for lights and to charge the battery, while an enduro specific header pipe and a new silencer finish the modifications.
With a limited number of changes made to each of the two-stroke models, the bikes have, expectedly, very similar track manners to the '06 models. All the bikes handle well despite not getting the new SX chassis and swing-arm, and produce power that is, with the exception of the 125, all but the same as '06 models.
Despite wading in with what is the best 250cc four-stroke enduro bike on the market, KTM's cylinder modifications have also ensured that its 125cc two-stroke is more powerful than the existing model. Offering a strong, smooth power supply, when worked hard the motor is extremely capable, giving KTM two fantastic bikes in the Enduro 1 class. Offering a near faultless package, the 125 matches an easy to use and powerful motor with an extremely well-mannered chassis.
The 200, 250 and 300cc EXC models are virtually identical to ride to the existing models, which certainly isn't a bad thing. The 200, although having no official class, is still a great all round bike, while the 250 and 300 are every bit as easy to ride as they are competent and enjoyable.
With the exception of the new quarter-litre four-stroke, the 400cc, 450cc and 525cc models are virtually identical to this year. The 400 is as enjoyable to ride as ever, offering an extremely manageable power supply and great handling which results in it being a pleasurable all-round package.
The 450 is also hard to fault. A more serious race tool, the extra grunt and top-end performance of the 450 over the 400 gives the bike a much racier feel while also making it a little less agile. While the handling of the bike is good, the extra 50cc makes a noticeable difference and makes the bike a little harder to boss around, especially in tighter woods sections.
The 525 is every bit as powerful as the existing model, which some riders will love and others shy away from. Producing more power than most British enduro riders will ever need to use, the bike handles every bit as well as the other '07 EXC-F models while the plentiful supply of power allows for less focused rider input.
Which leaves the best till last - the 250 EXC-F. Having proved itself in its first year of World Enduro Championship, the long awaited production version of the 250 EXC-F is every bit as good as its WEC results suggested it would be. Replacing the weakest model in KTM's EXC line-up, the 250EXC-F goes from being the worst to the best of the bunch.
Adapted to woods-use the quarter-litre motor produces a subtle mix of easy to use bottom-end power with a high-revving and potent top-end.
Everything about the 250 EXC-F, with the possible exception of the spongy front brake that all the EXC machines seemed to suffer from, worked well from the performance of the motor to the bike's handling and its suspension. As a result the complete package is one that both Clubman and Championship class riders will enjoy and be competitive on.
Producing an extremely gentle and manageable bottom-end power delivery, the 250 EXC-F doesn't initially feel noticeably better than other available quarter litre thumpers but when the motor is revved a little more it produces a deceptively strong mid-range and an extremely impressive top-end.
With most 250cc four-stroke models needing to be ridden in 'the correct gear' at all times, the KTM can be laboured in higher gears, which puts it at a huge advantage over its rivals too.
Allowing the power to be rolled on and off with out excessive use of the clutch, when the bike does start to produce its power it revs to the moon in much the same way as the motocross bike does. Easy to use off the bottom and impressively powerful at the top-end, the motor is as near to being the perfect all round power plant that there is.
Matched to the motor's impressive performance is a chassis and suspension set-up that ensures the bike is every bit as easy to manoeuvre - at both high and low speeds - as it is capable of inspiring confidence and setting winning special test times.
In short, KTM's 250 EXC-F is not only a great all round bike that will appeal equally to riders at opposite ends of the British Enduro Championship, but also a bike that will be at home in both competitive enduro and cross-country events and non-competitive trail rides. The bike comes as close to scoring 10/10 as any enduro bike on the market.

TECHNICAL SPECIFICATION 2007 KTM 250 EXC-F

ENGINE
Type: Single cylinder, four-stroke, 4 Valve DOHC with finger followers
Displacement: 249.5cc
Bore/Stroke: 76/55mm
Compression Ratio: 12.8:1
Starter/Battery: Kick-starter and E-Starter/4 Ah
Transmission: Six-speed
Carburettor: Keihin MX FCR 39
Lubrication: Pressure lubrication with two Eaton pumps
Primary Ratio: 22:68
Final Drive: 14:38 (13:52)
Clutch: Wet multi-disc clutch, operated hydraulically
Ignition: Kokusan digital 4K-3B
CHASSIS
Frame: Central double-cradle type, 25 CrMo4
Subframe: Aluminium 7020
Handlebar: Magura, Aluminium 28/22mm
Front Suspension: WP-USD, 48 mm
Rear Suspension: WP PDS shock absorber
Suspension Travel Front/Rear:
300/335mm
Brakes Front/Rear: Disc brakes 260/220mm
Rims Front/Rear: 1.60 x 21"/2.15 x 18" Excel
Tyres Front/Rear: 90/90-21"/120/90-18"
Main Silencer: Aluminium
Steering Head Angle: 63.5°
Wheelbase: 1.475 ± 10mm
Ground Clearance: 380mm
Seat Height: 925mm
Fuel Capacity: 7 litres
Weight: 107.2kg (without fuel)


Serious SX appeal


SAT in the conference room at KTM's ultra-modern headquarters in Mattighofen, Austria, two weeks ago, listening to the technical presentation of its 2007 model range, I glanced around the room at the 20 or so championship winning factory machines lining the walls. From the World 250cc motocross title winning machines of Guennady Moisseev and Heinz Kinigadner to multiple Dakar Rallye-winning steeds and even the full factory 85SXS piloted to the Junior World title by American Zach Osborne in 2004, there was a serious amount of off-road history dotted around the room.
Two bikes in particular stood out to me though, Gio Sala's 1999 World Enduro championship winning 400EXC and Joel Smets' 500cc motocross title winning bike from 2000. Both machines are less than a decade old but with Jonathan Barragan's stunning pre-production 450SX-F basking in all its glory in the middle of the room and details of the exciting new range of SX and EXC machines steadily being revealed, both machines looked seriously agricultural and really put into perspective just how far KTM has come in recent years.
With its 2007 SX models, the company has taken perhaps its biggest step forward yet, going back to the drawing board to develop its second completely new machine in two years with the ground-breaking total re-design of the long standing and proven flagship 450SX-F machine, completely overhauling all chassis aspects of the entire range resulting in a radical new look, and ploughing into an impressive number of developments across the entire range of two-stroke and four-stroke machines that result in a range of machines all significantly improved as a complete package, cementing KTM's 'Ready to Race' mantra like never before and marking them out as the most progressive manufacturer in the off-road market currently.
Leading the way for KTM in 2007 is the all-new 450SX-F. The first production motocross machine to solely sport an electric-starter unit, this development could well point the way to the future for four-strokes but the 3Ah battery-powered unit is not the only talking point for the bike.
Completely new from the wheels up, the four-speed 449cc DOHC unit is unlike anything KTM has produced and has gone from paper concept to production in an impressively quick period of time and arrives almost identical to the factory machine ridden by Jonathan Barragan in the this year's MX1 world championship. Smattered with magnesium and titanium, the whole weight of the motor is kept below 30kg and KTM is confident that not only does it produces the most power in its class, the 450SX-F is the most rideable and tractable too.
Not content with just developing a new motor, a complete new chassis has been designed to complement the 450SX-F's motor and provide significantly improved handling and comfort, which has also been ulitised on the entire SX range for the same reasons.
The chrome-moly frame now features ovalised tubing which has the dual benefits of reducing the frame weight by 1.5kg and increasing rigidity and controlled flex, while allowing for unique design features such as integrating the cooling system into the frame triangle for improved cooling efficiency. A new cast aluminium subframe and swing-arm futher improve strength while reducing weight further.
Closed cartridge 48mm WP forks previously only used on the SXS semi-factory machines and a new PDS WP shock have been added to produce more progressive and tuneable suspension action and a new wavy Brembo front brake provides extra stopping power, but obviously the most distinct and obvious chassis development is the radical new bodywork.
More than purely cosmetic, the new shape fuel tank, saddle, rad scoops, airbox, sidepanels and rear mudguard combine to promote a slighty wider, more comfortable and most importantly a more controllable bike that feels distinctly less 'European' and much more neutral, in the vein of the Japanese manufacturers.
The design used to achieve this may not be to everyone's tastes, but on the track it works and all the bikes feel much more comfortable. The meticulous details stand out on the bodywork too, like the graphics being integrated into the rad scoops so that they sit flush with the plastic with no raised edges so that they do not scuff or peel away.
The SX range of engines have not been neglected as a result of the huge effort made on the chassis development though and the two-stroke models recive particular attention, with both the 125SX and 250SX receiving new, more compact cylinders and heads and water pump impeller to further increase performance and durability, while the 250SX also benefits from a new flywheel for smoother power delivery and V-Force reed block for better throttle response. Both bikes are also fitted with a dual-curve Kokusan ignition which is debuted on the entire range and allows riders to choose either a best performance or best rideability curve by simply pluging in or unplugging a cable on the headstock mounted CDI.
Putting the bikes through their paces during two half-day test sessions - one dry, one wet - at KTM's test facility near the factory, time was not sufficient to bring you a full examination of the SX range, so think of this as more my 'first impressions' of the bikes.

125SX...
WITH the Japanese manufacturers seemingly turning their backs on the two-stroke market, it was a relief to hear the KTM engineers confirm during our factory visit that the company fully intends to continue to develop and produce two-stroke machines for the motocross market and with the 2007 model 125SX they have shown this in some style. It is an absolutley fantastic machine.
With the new cylinder and head producing more power and raising top-end performance even further and the addition of the new chassis, which sheds over three kilos in weight over the 2006 model, as a complete package it is the machine all others must beat.
Once again, KTM has come up trumps with the motor and the new cylinder and head give it even more fizz in the mid-range and top-end. The bike is still as strong as ever off the bottom. Get on the pipe from the mid-range up and it is significantly faster with fantastic over-rev. Really get on the gas out of tight turn, change up to third and it is amazing how the bike just keeps on pulling, and you can hold gears for what seems like an eternity, it's so much fun.
That KTM has further increased the performance of its motor is impressive but when I got the little beauty out on track and started to put down some laps it was the reduced weight, improvment in the overall handling and general comfort that the new chassis affords the bike which impressed most.
While the 125's cornering has always been one of its selling points, the precise riding and body placement needed to get the most out of two-stroke machines meant that the extremely slim nature of the bike could at times be a little detrimental to rider control, but the 2007 model benefits most out of all the bikes from the new bodywork that adorns the range and the slight extra width in the seat and through the tank area that it provides just gives you that little bit more to grip with your knees and thighs, making it easier to move around the machine and really throw it around in turns, improving the already formidable cornering prowess of the bike. It also makes not just the 125SX, but all the machines, a much more comfortable ride too.
Teamed with this, the new closed-cartridge 48mm WP forks, new WP shock and re-designed cast aluminium swingarm further improve the bike's handling. The rear end in particular felt much more progressive and supple on big kickers and bumps out of corners and although the front was still set a bit hard for my liking it coped with braking bumps and big landings far better than previously and created a more predicatble and precise ride.

250SX-F...
KTM's first ever 250SX-F offering exceeded all my expectations when I rode it in Portugal last year. Producing incredibly strong, yet linear power, with fantastic traction, which made it almost ridiculously easy to ride, it was great machine and was undoubtedly my bike of the year. The 2007 model is even better and just like its MX2 class sibling, the 125SX, the biggest improvements to the overall performance of the 250SX-F have come from the new chassis.
With KTM confident that the bike will still out-perform all its rivals in the power stakes, the only engine changes come in the shape of modified camshafts, which were developed to produce smoother power for the new enduro version of the motor, a shorter kickstart and new two-piece clutch unit cover for easy access.
As a result, the only notable difference in the bike's engine performance out on track is that it was perhaps just that little bit smoother and therefore allowing you to be even more agressive on the throttle and push even harder than the already deceptively linear power encourages you to do. However, placing the motor inside the new chassis has significantly improved the all-round handling and stability in much the same way it has the 125.
The increased contact area aids cornering, all round control of the machine and comfort, while the new shape of the tank and frame allow for a lower centre of gravity and a more stable and planted ride, particularly on the front-end. The increased performance of the WP fork and shocks combine with this to further eliviate the slight wandering and unpredictability the front-end occured on rough straights and in the braking zone and the end result is a bike which now has a chassis to match the quality of its motor, which is a formidable package and one which I think will see the 250SX-F remain at the top of the 250F tree without much bother.

250SX...
THE 250SX has been much maligned over the past few years as the weak link in the KTM arsenal, building a reputation as a difficult bike to ride, but KTM has stuck with it and with the addition of the new cylinder, head and fly-wheel it has managed to smooth the power delivery and produce a more controlable and enjoyable bike to ride.
The biggest issue I had with previous incarnations of the 250SX was the big hit of mid-range power, which made it an unpredictable and challenging ride, but the 2007 model is a big improvement and produces a much more linear and controllable motor that will suit the majority of riders better.
Out of corners where the older models suddenly took off and could leave you behind if you weren't careful, the 2007 250SX is much more controlled and useable. Don't get me wrong, it is still an absolute horsepower monster and goes like the wind when you get it wound up, it's just that it reaches that point in a way that does not scare the pants off you anymore.
The big selling point of the bike to me was the dual-curve ignition. Pulling the cable out to smooth off the power even further created a fantastic bike and I'd have prefered it if the bike came as standard with this power delivery as it would suit most riders far better in this state.
As with the rest of the range, the chassis development significantly improved the handling and comfort of the bike and all together I was pleasantly surprised by the progress KTM have made on this bike.
450SX-F...
What else can I say apart from the 450SX-F is a fantastic bike.
With a fantastic wide spread of smooth, strong, yet immensely useable power, a superb chassis with great handling and cornering capablities and the added labour saving device of an electric starter, KTM has really come up trumps with this bike and has well and truly forced its way back to the top end of the 450 class tree.
I was a big fan of the last few incarnations of the 450SX-F motor thanks to its incredibly smooth and forgiving power delivery and I was half expecting the 2007 model to be a complete opposite, but the second I pushed the electric start button and took to the track my fears were not compounded and I found a bike that, although definitely more powerful, was acutally smoother and even more rider friendly.
Producing around 4bhp more power than the 2006 model according to the KTM engineers, the bike is noticably faster and produces a stronger power delivery out on the track, particulary in the mid-range, and the higher revving DOHC motor picks up right off the bottom end much quicker than the old motor, but just like with the 250SX-F, KTM has engineered the bike so that it delivers it in an even smoother way. The result is a bike that is so forgiving and rider-friendly that it almost feels like a 250F and despite the extra grunt you feel confident to push harder, and with the four-speed gearbox you can pretty much just stick it in third and ride.
Similary to the 250SX, the dual-curve ignition was a real benefit on the 450SX-F also, especially on the second day of testing when its was wet, and the extra smoothening off of the motor that the 'best rideability' setting produces would probably suit the majority of clubman riders better in all conditions, but whichever engine setting is chosen you won't be disappointed with the engine's performance, it really is very good indeed and you won't be disappointed by the electric starter system either.
Of course, a strong engine is nothing if the chassis is a dud and with the new chassis designed for the 450SX-F it now has the chassis to match the motor and completes a fantastic package.
Like the rest of the range, the developments to the frame, swing-arm, suspension and bodywork all combine to promote a much more comfortable, forgiving ride. The big improvement all these modifications have produced has been a lowered center of gravity and resulting increase in the bike's feeling of balance. The improvements made to the front-end stabilty have eliminated the slighty light and loose feeling that you used to get on the front-end and significantly improved the cornering abilites and general confidence in the bike.
The result is a front-end that you have much more confidence in all round and a bike that handles superbly well, corners even better than ever and feels as well balanced, stable and comfortable as anything the Japanese currently have to offer.
All in all a great machine and a fantastic acheivement by the men from Mattighofen.

TECHNICAL SPECIFICATION 2007 KTM 450SX-F
ENGINE
Type: Single cylinder, four-stroke, 4 Valve DOHC with finger followers
Displacement: 449.3cc
Bore/Stroke: 97/60.8mm
Compression Ratio: 12.5:1
Starter: Electric-starter/ 3Ah
Transmission: Four-speed
Carburetor: Keihin MX FCR 41
Lubrication: Pressure lubrication
Primary Ratio: 29:74
Final Drive: 14:52
Clutch: Wet multi-disc clutch, operated hydraulically
Ignition: Kokusan digital Dual-Curve CDI
CHASSIS
Frame: Central double-cradle-type, 25 CrMo4
Subframe: Aluminium 7020
Handlebar: Renthal aluminium, 28/22mm
Front Suspension: WP-USD, 48mm
Rear Suspension: WP-PDS shock absorber
Suspension Travel Front/Rear:
300/ 335mm
Brakes Front/Rear: Disc brakes 260/ 220mm
Rims Front/Rear: 1,60 x 21"/2,15 x 19" Excel
Tires Front/Rear: 80/100-21"/110/90-19"
Main Silencer: Aluminium
Steering Head Angle: 63,5°
Wheelbase: 1475 ± 10mm
Ground Clearance: 380mm
Seat Height: 925mm
Fuel Tank: 8 Litres
Weight: 104 kg (Without Fuel)

Specification:

 

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