The orange army!
By TMX Archives on 5th Aug 09
SO, following the mega Dirt 3-2-1 weekend at FatCat Motoparc in Doncaster, where KTM UK cleverly grabbed the chance to launch their 2010 range of adult MXers, editor JD gave me the opportunity to test ride the very same shiny 2010 KTMs that had been on display, the morning after the event, writes JOHNNO WHITE. Obviously I said Yes! and off I raced to FatCat on a rainy Monday morning.
Once on site, I had a good look round the bikes and found that for once KTM have kept their 2010 bikes pretty much the same as last year, which kind of says that they were already pretty good in 2009.
Just looking, the first thing that catches your eye is the new brighter colour scheme and graphics and new Renthal diamond grips but other than that there are not a lot of other cosmetic changes. The rest of the updates are internal and I'll tell you about them as we go through the range, bike by bike. It is also really good to be able to test both four-stroke and two-stroke models as KTM is about the only manufacturer actively promoting their strokers - and I've always been a 125 fan...
450SXF
THE first bike I rode was the 450 SXF and before I rode it, I looked down under the tank and was pretty surprised to still see a carb still sitting there, especially as most of the other 450s - mainly the Japanese ones, are going fuel injected. But KTM's motto of "don't fix what aint broke" jumps in here, although I'm sure they will go down the fuel injected road before long, but just not for 2010. But even though it still has a carb on for 2010, it does come with a new low-end setting to improve power delivery. And some owners still prefer a carb because they understand it and can fix it when something goes wrong!
But, on with the test. Without a doubt the the best thing about this bike has to be the electric start. I loved it. I think that's probably because I'm getting older and can't reach the kickstart any more!
So, having fired it up effortlessly on the button I went and did a couple of laps on the big 450 and almost straight away I felt comfy on it. The low down grunt is perfect I found that it was easier to ride when I pulled higher gears and just let the motor do the work rather than rev it to the max.
I really enjoyed riding it and felt like I was almost on rails because it was so smooth. The new carb setting has made a definite improvement and it seems to workperfect with the new five-speed transmission.
Cornering the 450 was also a lot easier than previous models and there are several reasons for this. For 2010 it comes with a new frame design which now has the frame welded to the steering head 10 mm lower, which lowers the tank and seat position. It also comes with a new triple clamp design, patented to KTM, with a fixed offset of 22 mm instead last years 20 mm.
This was a major improvement and seemed to make the front end a lot more controlable. I found I could hug the corners tighter with confidence. The forks have also been improved with new fork seals and bushes to reduce friction and improve the overall feel to the front end and also to work in conjunction with the new triple clamps.
KTM is the only serious manufacturer out there running a linkless rear suspension system. The obvious advantage is that you don't have the weight, complexity and expense of all the linkage - just a clever shock unit mounted direct to frame and swinging arm. The disadvantage is a stiffer feeling during the initial movement and the action is not always constant at low speeds - occasionally you get a 'kick' when hitting a bump for no apparent reason. But once you get dialled-in you don't notice the difference. The faster you go and the harder you hit stuff the better the system seems to work. You certainly don't think about it once you're riding, you just get out there and race.
The seating position is nice and comfy and the handlebar setting was perfect for me and the brakes and hydraulic clutch worked spot on all day. It must be a fairly easy bike to ride as I was on it for over an hour and never even came in for a breather and I'm an old guy now... so overall its a pretty good bike and obviously a major contender in the big bike league.
250SXF
MOVING down the four-stroke scale, the next bike I rode was the 250SXF and this model has been treated to similar mods to the 450 which include the new graphics and brighter colour scheme. It also comes with the patented triple clamp design with the 22 mm fixed offset, new improved forks with new seals and bushes to reduce friction and improve comfort. There's also new brake pads from Toyo to give a better, more progressive feel and a new improved airbox design to help with filter protection.
On the track this bike was really impressive and I can see why KTM haven't made too many changes to this bike. It has to be said that the 250SXF has led the way for a good few years now in the MX2 class. It is really fast and it's actually hard to believe it's not a bigger motor - it really is that strong.
The gearing was perfect and like its big brother the bike has a really smooth feel to it. I found you could really let the motor rev right out or just pull higher gears and use the torque. It says a lot that it can be used either way, which kind of says it is good for anyone, clubman or expert. The suspension wore well and it corners a lot better than last year's bike which will probably be down to the new offset clamps. Like the 450, the seating position and the handlebars were spot on and all controls had a real positive feel to them, The rear shock also had a real nice feel to it and enabled it to hook up real quick .
Like its big brother, the 250 also comes with a carb and not fuel injected like most of its Japanese competitors who all seem to be going FI for 2010 but the carb works fine. All in all its another really strong bike from KTM and I'm sure that, once again, it will be one of the main contenders for next season.
125/150 SX
THE next bikes I rode were the hot little 125 and 150 two-strokes and as always I had a smile from ear to ear when I was buzzing round on these bikes. I've always enjoyed riding small-bore
strokers.
Again they haven't gone through many changes other than a new frame with a steeper steering head which helps cornering and gives a better feel to the front end.
It was mega-easy to ride the 125 which was really quick and the gearing was perfect, even the jetting was spot on. In fact, all the bikes provided for test were set-up absolutely perfect. I tried a couple of practice starts and the 125 pulled first perfect and second was OK but on the 150, second was just mega.
I normally love 125s and this one was no exeption but I have to say I favoured the 150 this time. I don't know if it's because I'm a bit heavy at 13 stone to be on a 125 but I really found the 150 coped with my extra weight better than the 125. And the 150 really is a bit special having been stroked, it isn't just a big-bore job.
But being honest, I'm not really sure what the point of the 150 is. Yes, I know its because you can race it in MX2 but in all honesty it is never going to beat a 250F in a straight race. It's a shame as the 150, with its revised bore and stroke, is an absolutely cracking bike. I reckon it would make a perfect Cross Country bike because it is so light and easy to ride like a 125 but has more torque - yet still revs out really hard.
The way both bikes cornered was brilliant as KTMs have been known for a having stiff front ends and being bad to turn but this year the new offset clamps have really made an improvement. Both bikes are jetted perfect, run super-sweet and have a real nice almost factory feel to them and were both an absolute pleasure to ride.
It's a real shame that the 125 and even the 150 models get lumped in with the 250Fs as the little strokers are fantastic fun to ride and also help keep the cost of racing down.
250SX
LAST but not least for me to fire-up was the 250SX and my by-now tired body was protesting. Again, apart from the steering tweak it is pretty much >>> as-you-were. The factory has come up with a new exhaust pipe with extra wall thickness, up from 0.88 mm to 1.00 mm, to make it stonger and stop it getting damaged from stones. There's also a reinforced cylinder head to improve durability and give an overall smoother feel to the delivery of the power. Other than those two mods it also has the lovely triple clamps to help it steer better than previous models and the new fork seals and improved bushes also make it have a much plusher feel to the front end.
Out on the track I was pretty happy riding the 250 stroker but did find it a little bit aggressive from the bottom end but that could be down to having been riding four-strokes most of the day and then the smaller, revvy two-strokes.
As time went on I did get used to it and can see why KTM make such good enduro bikes as the low down grunt would work pretty good in the woods. But being honest, for MX I found it just a bit too snappy. I reckon a smaller rear sprocket would suit this bike better and take the edge off the initial hit. The suspension worked real good although I found the rear shock just a bit harsh. Being in the suspension tuning business I do know that this can be fixed if it bothers you that much. Brakes and controls were factory and the jetting was absolutely perfect.
All in all another good bike from KTM's extensive 2010 off road mx range. Again, its just a shame that unless you just ride in a two-stroke series you are going to be out-gunned in the MX1 class.
CONCLUSION
KTM has the most comprehensive range of off-road bikes out there with virtually all the bases covered. The 250F and 450F models are obviously the big hitters and the 250SXF is a particularly impressive bike with the holy grail of combining top-end performance with excellent torque through the rev range. I also loved the 450 and rode it for ages without getting tired.
The two-strokes are also really cracking bikes with excellent performance - the only problem is finding a class to actually race them in but if you like your strokers, these are as good as they get.
I've ridden KTMs for years and the only thing I'd say is they were always a bit slow on the steering. This has now been fixed thanks to those wicked triple clamps - so the 2010 range really is genuinely hard to fault.
SPECIFICATIONS
2010 model KTM 250SXF and 450SXF
ENGINE
Type: Liquid-cooled single cylinder four-stroke with 4-valve DOHC with finger followers
Displacement: 248.6 cc/ 449.3 cc
Bore x stroke: 76 x 54.8 mm/
97 x 60.8 mm
Compression ratio: 12.8 : 1/ 12.5 : 1
Starter: Kick-starter/ Electric-start
Transmission: 6-gears/ 5-gears
Carburettor: Keihin FCR MX 39/ FCR MX 41
Lubrication: Pressure lubrication with 2 oil pumps (250)/ 3 oil pumps (450)
Engine lubrication: 10W50 oil
Final drive: 5/8 x 1/4'' chain
Clutch: Hydraulically operated wet multi-disc unit
Ignition: Kokusan
CHASSIS
Type: Chrome-moly central double cradle with aluminium rear sub-frame
SUSPENSION
Front: 48 mm WP USD with 300 mm travel
Rear: WP PDS shock absorber with 335 mm travel
BRAKES
Front/ Rear: Hydraulically operated disc brakes 260/ 220mm
TYRES/ RIMS
Front: 80/100-21'' tyre on Excel 1.60 x 21'' rim
Rear: 100/90-19'' tyre on Excel 2.15 x 19'' rim
Main silencer: Aluminium
Handlebar: Renthal aluminium with variable 28/22 mm diameter
DIMENSIONS
Wheelbase: 1,475 ± 10mm
Ground clearance: 380mm
Seat height: 985mm
Fuel capacity: 8 litres (approx)
Dry weight (approx): 98kg/ 104.6kg
SPECIFICATIONS
2010 model KTM 125SX/ 150SX/ 250SX
ENGINE
Type: Liquid-cooled single cylinder two-stroke with TVC control valve
Capacity: 124.8 cc/ 143.6cc/ 249cc
Bore x Stroke: 54 x 54.5 mm/ 56 x 58.4mm/ 66.4 x 72mm
Starter: Kick-starter
Transmission: 6 gears (125/150)/ 5 gears (250)
Carburettor: Keihin PWK 38S AG (125/150)/ PWK 36S AG (250)
Lubrication: Fuel/ oil pre-mix @ 40:1 (125/150)/ @ 60:1 (250)
Final drive: 5/8 x 1/4'' Chain
Clutch: Hydraulically operated wet multi-disc clutch
Ignition: Kokusan
CHASSIS
Type: Chrome-moly central double-cradle with aluminium rear sub-frame
SUSPENSION
Front: 48mm WP USD with 300mm travel
Rear: WP PDS shock absorber with 335 mm travel
BRAKES
Front/ Rear: Hydraulically operated with 260 mm/ 220 mm discs
TYRES/ RIMS
Front: 80/100-21'' tyre on Excel 1.60 x 21'' rim
Rear: 100/90-19'' tyre on Excel 2.15 x 19'' rim
Main silencer: Aluminium
Handlebar: Renthal aluminium with variable 28/22mm diameter
DIMENSIONS
Wheelbase: 1471 ± 10mm (125/150)/1475 ± 1 mm (250)
Ground clearance: 390 mm (125/150)/385mm (250)
Seat height: 985mm
Fuel capacity: 8 litres
Dry Weight: 90.8 kg (125/150)/ 95.4kg (250) (approx)
Engine updates
TWO-STROKES
ALL three popular two-stroke models come with new exhaust pipes. The wall thickness in the pipes has increased from 0.88 to 1.00mm to offer increased resistance to stone and crash damage.
On the 125 and 150 SX models, first gear has been beefed-up to offer improved durability.
It's a similar target, improved durability, on the 250SX where the cylinder head has been reinforced.
FOUR-STROKE
OVER on the big brother 450 SX-F the piston has been re-inforced by increasing the wall thickness by 0.5mm, to offer improved durability.
In addition there are revised low-end carb settings to give improved ridablity and power delivery.
And finally there's a new five-speed transmission, which KTM says offers better overall settings.
Specification:
