2012 Two-Stroke SX
If you think that two-strokes are dead, well, you’re wrong. While only one Japanese company (Yamaha) continues to build two-stroke MXers, KTM hasn’t given up on the lightweight, simple and low-maintenance oil burners. With two-strokes still a very popular sector of KTM’s U.S. sales (5000 units sold in the U.S. last year including off-road and MX, according to KTM’s media manager), the Austrian off-road powerhouse has continued to develop this segment of its motocross lineup, which includes the 250 SX, 150 SX and the 125 SX, the latter of which returns after a two-year absence.
Key to the redesign on all three bikes is the adoption of linkage rear suspension, including a new frame, swingarm and WP piggyback-reservoir shock. The shock attaches to a new upper mount and is rising-rate-linked to the cast-aluminum swingarm. Up front, the 48mm WP upside-down closed-cartridge fork gets new seals, bushings and valve specs. New reinforced rear fenders, airboxes, rear numberplates and a new pad for the Renthal handlebars round out changes to the SX smokers.
2012 Four-Stroke SX
Momentum has been building with KTM’s line of four-stroke MXers. Success on and off the racetrack has resulted in various awards presented to KTM for its 450 SX-F, 350 SX-F and 250 SX-F Thumpers.
The 450 remains largely unchanged except for a new clutch with a steel basket and single diaphragm spring. The class in-betweener, the 350 SX-F, also receives minimal changes to the engine with new engine-management mapping. The biggest news is that the 250 gets an industry-first electric starter in quarter-liter four-stroke motocross class. If you still want a kickstarter it will have to be ordered through KTM’s PowerParts accessory catalog.
Changes across the four-stroke range include a new serviceable in-line fuel filter and a rubber protector for the venerable throttle-position sensor. For those who buy the optional accessory EMS Setting Tool to alter ignition and fuel mapping, a new handlebar-mounted, three-position map-selection switch is available from PowerParts.
2012 SX Minis
Kids looking for serious racebikes have often turned to KTM’s 50 SX, 50 SX Mini, 65 SX and 85 SX. For 2012, these bikes feature a host of upgrades, including new suspension and settings, while the 65 and 85 get Rental handlebars and four-piston front brake calipers.
