This is the 2010 KTM 250SXF the way the MXA test crew raced it. As a rule, we don’t go for exotic or expensive mods, but if push comes to shove, we will seek competent help (no matter how much it costs). Use MXA’s mods as a guide.
The archaic Bridgestone M59/M70 tire combo on the 250SXF works well, but for intermediate-to-hardpack terrain, we swapped the old-school sneakers for Bridgestone’s M403/M404 combination.
We thought about enlisting the services of Chris Angel to show us how to make the 2010 KTM 250SXF levitate onto a bike stand, but then we realized that Chris Angel is probably a few cards short of a full deck. Instead, we took a box-cutter to the right-side panel and made a curved cutout. Following the Frankenstein-like cut, we buffed the edge with sandpaper.
Adjusting the accelerator pump screw is a must-do on the 2010 KTM 250SXF. We turned the screw in until it made contact with the pump and then backed it out 1/4 of a turn. From the contact point, back the adjustment screw out (counting turns as you go). Otherwise, the bike will bog directly off idle.
The biggest handicap on the 2010 KTM 250SXF is the WP forks. In stock trim, they are very harsh—especially midway through their stroke. We fiddled with the oil height by decreasing it in increments of 5cc until we found fairly acceptable results. Removing 15cc of oil out of each fork leg minimized the midstroke spike, but the forks still needed help. We enlisted the services of Pro Circuit, and the results were impressive. Pro Circuit revalved the forks and utilized special spring tubes that allowed easier flow of oil through the forks. Finally, the dreaded midstroke harshness was gone. The fix costs $675.80. For more information, visit www.procircuit.com or call (951) 738-8050.
The stock gearing would work at the drag strip, but not on a motocross track. The stock 48-tooth rear sprocket is too tall. We installed a Renthal 49-tooth rear sprocket. This change is a must, and it wouldn’t hurt to consider a 50-tooth rear. Visit www.renthal.com or call (877) 736-8425 to order.
The small patch of real estate on KTM side panels makes it difficult to fit numbers. We had DeCal Works make preprinted numbers that were super easy to install. DeCal Works offers several different styling options, but if you like ours, just tell them you want the MXA look. View their entire line at www.decalworks.com or call (815) 784-4000.
Front brake pads:
Nearly every member of the MXA wrecking crew loves powerful front brakes. The increased stopping power allows us to go deeper into corners and out-brake the competition. For several years, the KTM 250SXF has come equipped with the best front brakes in the class. The same can still be said for 2010, but KTM did change the brake pad compound for better actuation and less stopping power on this year’s 250SXF. Once the stock pads wore out, we switched to the 2010 KTM 450SXF front brake pads. These pads have the same compound as last year, and they make the 250SXF stop on a dime.
KTM Motorcycle tests