Dirt Bike Magazine - November 2014

THE FASTEST AMERICAN’S

ISDE MACHINE

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FACTORY BIKES: INSIDE THE KTM 500 HYBRID

tolerances. The result is increased sensitivity, more fine-tuned damping, the ability to set it up stiffer yet stay plush, and the capacity to open it up farther than a shim fork, which helps reduce harshness.

With the Trax shock, similar manufacturing-tolerance enhancements make for a more fine-tuned setup and better damping. The system has a built-in design that actually lets it ride higher over continuous hits that normally plague a shock and cause packing. The result is a more balanced feel, increased traction and stability in course terrain. Also, the damping has increased adjustability for enhanced control.

The engine started life as a 450XC-F powerplant. In stock form, this machine is a beast and is used by the factory KTM off-roaders in the National Hare and Hound series. Anthony and Taylor wanted a more friendly approach to the powerband and opted to fit it with a

500XC-W crank, which has a longer stroke. The actual bore is identical to the 450’s (95mm), while the stroke stretches from 63.4mm to 72mm, making it into a 510.

This completely altered the powerband, making it much more bottom-to-mid strong with a good mix of top-end over-rev. Compared to the 450, the 500 will short-shift and claw for traction rather than spin and snarl. Taylor says it lets him use the power to find traction, and it actually relaxes the suspension and chassis—when he rides it correctly. When he gets throttle-heavy and tries to rev the 500, it beats him up.

One reason for the broader power of this 500 (over a standard 500XC-W) is that the throttle body from the XC-F line has the injectors mounted on the bottom. This change alone makes a substantial improvement in overall response and is one of the reasons every major motocross team runs the KTM-type throttle body on

Taylor runs 14/48 gearing with a five-speed tranny. For the Six Days he will run an Eco tire (lower knobs), and this he did at the OMA race just to test it.