KTM is a member of the club now called The Big Five, up from just the four Japanese brands that were competitive in the motocross arena; the Austrian bikes are now judged equally. Being held to those top-shelf standards can be tough; first, you come from a different continent (and world, really) than your competition. Also, when your home markets prefer a different kind of motocross bike than your biggest market (which is the United States) it makes it even tougher to compete. And in the U.S. the 250F class is as hotly contested as it gets. One thing's for sure, small-displacement bikes are made or sunk firstly on the engine.
KTM has had the 250F motor dialed from day one, especially in outright power. It has always had the beans, only the delivery and spread weren't perfect for some. It was a deceiving sensation; the motor had great torque but often left novice riders confused on where in the power spread to ride the bike. What they didn't grasp was that there was a ripping top-end waiting a little further up the rpm range. Experts were often put off by the flattening of the top-end before it pulled strong again even further up. Why couldn't KTM have bridged this gap? A lot of aftermarket pipe manufacturers were able to. Well, for 2008 it looks like the host of changes have accomplished a lot of this.
The intake tract has reduced volume, both cams' timing is changed and a new exhaust cam hides under the cover. Add a lighter circular crank with the weight positioned further out from center and you have a smoother power spread that seems to even fill in the potent midrange from last year as well as plug the little gap up top, making the total power pull much smoother and more full. If anything, the bike is reluctant to rev from a basement rpm, something a beginner may not appreciate. Above there, it goes and goes with a very long-winded top-end spread that seems to use timing to slow the speed at which the upper end rpm build. It's sort of "slow revving" up past 12,000 rpm. I'm sorry if that is the worst oxymoron you've ever heard, but it's true. Some riders like this, others thought the bike was signing off early. But hit a jump when the bike is working here and you launch as far as any 250F will throw you; drag race another bike singing here and you will likely win when your competition makes the next shift sooner.
The KTM's strong engine has no trouble making the orange thumper fly.
Clutch work isn't necessary on this bike, but when the time comes the feel is great, consistent and the bike responds well. Shifting is solid yet not as silky as some, but gear spacing is perfect for most every track. There is a noticeable amount of engine-braking on the SX-F but that's easily nullified with just a bit higher idle tuned into the carb. The jetting was spot-on for our hot summer SoCal testing from near sea-level to 4000-foot conditions. Everyone who rode the bike came away impressed with the motor and immediately noticed the improvements from last year. All this and it is remarkably quiet; KTM makes power and keeps the sound in check.
The chassis fights a whole other battle. It's because of the linkageless shock and the built-in perception that follows it. For sure, the shock and the resultant handling are not the same as the other four bikes in the class. It's typically more finicky about proper setup, and the setup will vary as a track changes, as well as from track to track. But just because the bike does something funny doesn't mean it's solely because of the shock. Straightaway, having the proper ride height and comparably correct bike-only static sag, all combining to show the bike has the right spring on it for the rider, is crucial. Then you just go and ride. Riders accustomed to other brands might feel the rear end as being a little looser or moving up and down a bit more than they like. But a little compression or rebound can usually cure that.