Road Test: KTM 250SX-F

KTM's much-anticipated double overhead cam 250 SX-F thumper is the only really new bike in the range and it's bristling with new technology. Pumping out a claimed 39bhp at 11,000rpm it will safely rev past 13,000 yet also makes excellent mid-range power, with a stonking 26.5 Nm of torque. KTM have used F1 car technology in coating their new 'finger' cam followers with DLC - Diamond-Like Carbon for increased reliability and the valves are titanium. They've dropped the cam gear drive of the first prototype works bikes of 2003 in favour of the more traditional cam chain, with a hydraulic tensioner. The redesigned engine, in factory racer form, proved powerful and reliable enough for Ben Townley to win the MX2 World Championship on it last year.

KTM say that no balancer is required thanks to the 'optimised balancing' of the crank and it seemed smooth enough. The bike is much easier to service than its SOHC predecessors - the side-mounted plug can be removed with the fuel tank in place and the valves can be checked with the engine in the frame. The six-speed machine weighs a featherweight 98.5kg including all fluids except fuel even though the frame is still made of tubular steel rather than trendy alloy. As with all KTM's 'crossers, the 250 SX-F is kick-start only. But unlike the 525 SX the new 250 has no manual de-compressor, merely a 'hot-start lever' instead.
I'm used to kick-starting dirt bikes big and small but this high tech little thumper proved to be a right little bastard to fire up, especially after a stall. And not only for me.

I watched several KTM mechanics trying to re-start mine before one of them finally got it going again.
To ride, it was great. Much easier than the 525. Although only 7.5 kgs lighter than the big'un, the difference felt much more. Yet the new 250 felt more like a 400 power-wise, with excellent handling and suspension (WP at both ends). It is bloody noisy though. But as I entered the home straight for the last time the pesky double jump caught me out again and I dropped the bike. Would it re-start? Would it buggery! By the time I got it going again the 250 SX-F had entered the tiny category of motorcycles that I have spent more time kicking than riding. Top enduro rider Jonty Edmunds reported spending ten frustrating minutes kicking a 250 SX-F and I also watched another journo being reduced to a gibbering, foaming ball of sweat as he kicked away for a full 15 minutes. Thank goodness the enduro version (due out next year) will come with a 'magic button'.

The enduro course was an 18km loop of dusty, stony woodland with one really steep and nasty descent, two tricky climbs and three river crossings. It also had a 'special test' in a quarry with a drop off and climb out which made the MX track look like a motorway. I did my first lap on a 450 EXC and was mighty impressed. It went up, down and over everything except the second steep climb, which was entirely due to my own incompetence. Pick it up, press the magic button, and away you go again. Great. With a modicum of skill it will go up just about anything short of a trials section, it stops and handles brilliantly and if you've got the space and the nerve to give it the berries, it goes like stink.

The 250 four-stroke EXC is identical in every dimension to the 450 EXC, apart from cubic capacity, but it somehow felt smaller and easier to ride down the hairiest descents. On the sandiest climb though, it felt short of poke.

The 400 EXC is, for me, the 'Goldilocks' among KTM's enduro four-strokes - just right. Whether you're trail riding or racing it's got plenty of go but the soft power delivery makes it more relaxing to ride than the 450 (let alone the 525). Ex-enduro world champ Giovanni Sala said that if he were riding all day, this is the bike he would choose. And good enough for me.

In conclusion, I'll take the 400 EXC for the trails please. You can keep yer fancy new DOHC 250 SX-F until it's got a nice magic button on it, thank you very much!

VERDICT

KTM's new 250 thumper is a right little beast, and when it comes with lights and a 'leccy start (2007) it'll will be a winner.