Recently, during the filming of the new Dirt Rider Adventures tv show, to be aired on the Outdoor Life Network, we had the opportunity to test ride two 2004 KTM E/XC four-strokes that 8-time National Enduro Champion Dick Burleson brought up to Canada for the show. While not featuring any breakthrough design changes, both bikes showcase technical improvements through evolutionary improvement, particularly on the chassis.As in the past, the 450 and smaller brother 250, share identical chassis specifications. Most notable for '04 is the inclusion of the airbox, seat, and one-piece rear fender and side number plates combination debuted on the '03 KTM 450 SX. The main frame has been stiffened around the swingarm pivot, with a one-piece forging that doubles as the lower attachment point for the subframe. The rear shock features upgraded valving and a single rate 8.8 Newton Meter spring as well as an effort to return the second piston in the shock to effectiveness with a PDS needle that comes into play earlier in the stroke. Newton Meters read just slightly higher for spring rates than kg./mm., so the spring is probably more like an 8.7 in ratings we are used to.Another notable change is an all-new rear brake system, with an integral reservoir, new brake pedal, and lighter brake caliper.The exhaust system is a lighter, 2 into 1 system, with an all new baffled exhaust muffler. The wheels are upgraded to Excel rims, and the handlebars fitted with custom gray and orange grips Renthal grips..The 450 E/XC engine has strong bottom power, with a good burst in the middle and solid top power. Editor Ken Faught, couldn't resist doing extended wheelies on this bike. The 2 into 1 pipe tucks in nicely, with the muffler emitting a solid throaty note. This is a bike with performance not suited for the timid or inexperienced, but designed for the likes of National Enduro Champion Mike Lafferty.On the other hand, the 250cc version was the ideal choice for show host Molly Culver, who is tall and had no problem with the seat height. The engine produces good pulling power, but not so much that it is hard to control for the less experienced rider. While the 450 version can cruise at speed, the close-ratio gearbox on the 250 limits its top speed to about 60 m.p.h.With a chassis perfect for serious trail riding, and suspension settings that absorb rocky terrain nicely, these electric start machines offer the choice of a smooth and mellow 250cc engine for the novice, or a full blown 450cc race machine for the expert.Look for a complete test in the September issue of Dirt Rider Magazine, and for the first edition of the Dirt Rider Adventures show on OLN to be aired on September 4.