Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/128163
~~WBikes 2m3 KTMs KTM offers an iDlpressive liDe-up for '03 · but what does the ZSO SX look like? OlEIC By Here's the lowdown on the models KTM is ready to show us. CHRIS JONNUM T he KTM everyone has been waiting to see is the 2003 250 SX, which has been tested extensively this year on the MX GP circuit and will be raced Stateside next year by KTM Red Bullon the AMA Supercross and Chevy Trucks National Motocross circuits. Unfortunately, we're going to have to wait a bit longer, as KTM still doesn't have photos of its flagship model, though the Austrian company has released technical details on the bike. Same goes for the 450 SX Racing four-stroke, which will go headto-head with Yamaha's YZ450F and Honda's CRF450R. The Austrian manufacturer also makes mention of an 85 SX in its literature, though there are no photos or specs. As for the Dakar-winning LC8 950 Adenture dual-sport bike, that's expected to be a late-release model (though you can expect a sneak-preview riding impression within the next couple of issues). 38 JULY 17, 2002' ICl U ICl •• MOTOCROSS We can't show it to you yet, but the 250 SX is a completely redesigned bike for 2003, from the engine to the frame. Regarding the former, KTM has repositioned the crankshaft in relation to the center of gravity, in an effort to improve handling. The cylinder is now positioned almost vertically, allOWing for a morecompact engine and a 15mm-shorter frame. Weight has also been cut throughout the mill. Clutch and ignition covers are now magnesium, for example, and the redesigned fivespeed transmission is slimmer and more compact. The clutch is also said to be lighter and slimmer, and the crankshaft (which has a plastic insert) is lighter and has less inertia. The connecting rod is shorter (bore and stroke are unchanged), so the cylinder is shorter and lighter. The n __ s piston is lighter, and so is the kickstart system. The frame has a shorter wheelbase (despite a 10mm-longer swingarm), and stiffness is enhanced via reinforcement. The rear-brake system has been redesigned as well. The 125 SX was already a bullet in '02 (it made the podium in our shootout), so not much has been done to its motor. The tranny is now just a five-speed (it was a six), and it has a wider second gear - a la the KTM GP racer. Shifting is said to have been improved, as well. KTM is adept at filling niches, and it hopes that its new-for- '03 200 SX will do just that. Based on the popular 200 EXC (see Off-Road section) motor, the SX has a different carburetor, exhaust valve and expansion chamber (all from the 125 SX). On the four-stroke front, the 400 and 520 have been replaced with a 450 (the new limit in the 250cc class) and a 525. Both now have die-cast cases (rather than sand-cast) to save weight, and their outer clutch hubs have been reduced by 100 grams. For quick engine response, the shortstroke 450 has a very light new crankshaft (and less inertia weight), as well as a light connecting rod. It also gets a four-speed transmission (like the new YZF) and a new cylinder head with bigger ports, along with titanium valves (which permit lighter valve springs) and a new Keihin FCR-MX 41 mm carburetor with hot-start knob. The exhaust system is chromium-plated with a singlepipe design and a lighter silencer. The 525 also gets the larger ports, 41 mm carb and lighter valve springs. Its crankshaft is lighter, and there's a new, lighter ignition system and digital-control electronics. Chassiswise, all of the KTM MXers will come with three-bearing (per tube) 48mm WP forks with an external preload adjuster and improved chromium quality. Triple-clamp offset was changed by 14mm for quicker steering. Front-axle diameter is