Second in line for first new bike of 2009 is the KTM 450 SX-F. Once a fiercely hard-edged motocrosser, the new and improved KTM is showing a more refined compliance that should gain it some new track-addicted fans in 2009.
Right away you know this KTM is different than last year's bike. One look into its graphics, one stare at the factory-colored fork and one glance at the blacked-out triple clamps and you'll see KTM's forward-thinking style is alive and well. But the beneficial changes don't stop with aesthetics.
Clearly the most noticeable improvement and most obvious to the eye is the new front suspension components. The fork on the 2009 450 SX-F shares similar construction refinements with the 250 XC we've already tested. Thinner tubes, stiffer springs and new valving put the fork action in a different direction: a much softer one. Really, KTM engineers accomplished something directly in line with what American customers will appreciate: a more supple, friendlier ride aboard an orange bike. Surely, more riders will feel at home with the new plushness. While the combination of the flex character of the setup and overall softer damping makes fans from novice to intermediate, pro-level riders will need to stiffen up the front end to keep from getting stuck in the wallows. Same goes for the shock, which has its own upgrades.
The linkageless shock out back on the 450 SX-F has an all-new PDS needle. This is the "linkage" in a dual-piston shock system. It acts similar to a carb needle in that upon compression, the amount of oil passing by the needle is reduced the farther the shock travels. When the needle closes off the bypass, the valving includes the secondary piston and the rate of damping force increases. The angle of the shock puts a certain amount of rising rate (like a linkage) on the shock, but the internal valving adds even more dimension to this.
The result of all this fluid dynamic needle business is a great rear shock feel. Again, better than the '08 and more friendly to a wider range of riders. We're pretty sure the shock plushness has a lot to do with the improved front end feel, too. Also mirroring the front, the shock seems to be on the soft side for the fastest riders in our testing posse. Dial it in by stiffening it up, and don't forget to use rebound adjustments for traction control!
Speaking of adjustments, the only really strange thing about KTM's suspension this year seems to be the sensitivity of the clickers. Our testers all felt the range of one click was huge. So huge that we were looking for half clicks. So click wisely. Or if you want to learn what things do, click recklessly and pay attention.
Inside the KTM's renowned motor is some enhancement worth noting. The motor nicely packages more bottom-end than a year ago with the same great overrev and top-end superiority. Everyone is in love with this motor, and since they've proven to have a solid track record in the durability department, we're more than confident giving it a positive endorsement. Changes internally include a new, lighter weight piston which is at least partially responsible for getting the SX-F motor into the revs sooner. The valve train has some updates (lighter finger followers, new valve springs and slightly different timing) to enhance this rev-up further. Also new in the head are revised intake and exhaust ports that match the all-new intake and exhaust manifolds which bookend the top end.