#motocross

It’s safe to say that Yamaha came about as close as a manufacturer can to setting the motocross world on fire with the YZ250F in 2014. Borrowing heavily from the architecture of its revolutionary YZ450F, the company’s all-new quarter-liter contender broke cover with a new, fuel-injected, rearward-inclined engine that places the straight downdraft intake out front and the exhaust in the rear. In addition to the new cylinder head’s symmetrical port design, which allowed Yamaha engineers to extract a lot more power from the engine, the compact engine allowed Yamaha to centralize the 250F’s mass in an all-new compact bi-lateral beam chassis that is shared with the YZ450F.

For 2014, Zero streamlined its product offerings to focus on its core products: the S, SR, DS, and FX. With the dirt-focused MX electric bike gone from the lineup, the FX has become the de-facto dirtbike currently in the Zero range.

Every other year dozens of countries attempt to set aside geopolitical, ethnic, religious, and cultural differences in order to gather in one host nation so that a select few citizens from each nation may participate in that spectacle of sport known as the Olympics.

The 2013 Suzuki RM-Z450 boasted an assortment of technical upgrades to the engine, chassis and electrical system improving both power and handling performance. The 2014 RM-Zs, not so much. In fact, besides new radiator shrouds and yellow number plates the only performance upgrade is a reprogrammed Electronic Control Module.

Suzuki made several updates to its 2013 RM-Z250 MX machine, adding numerous technical upgrades to the engine, chassis and electrical system to improve the power delivery and enhance handling. With so many changes made last year, and given the typical development cycle of the OEMs, it’s no surprise that the 2014 RM-Z250 returned to the MX wars in virtually the same trim. In fact, besides new radiator shrouds and yellow number plates the only performance upgrade is a reprogrammed Electronic Control Module.

With an all-new motor and chassis layout the 2014 YZ250F represents the pinnacle of Yamaha motocross design, and after testing it this week, we think it may have even surpassed its super-powered YZ450F sister as the best motocross machine in the Yamaha family.

For 2014, Kawasaki is introducing significantly updated versions of both the KX85 and the KX100 in an effort to stay one step ahead of its rivals in the never-ending battle for mini motocross supremacy.

Yamaha’s radical, reverse cylinder head YZ450F set the world on its ear when it debuted in 2010. Sure, the ill-fated Cannondale MX400 of 1999 had already introduced the concept to the motocross world, but the difference was that the Cannondale suffered from fuel-injection issues and a lack of power whereas the Yamaha worked well right out of the box. Today, the YZs are the only Japanese motocrossers to use this major mass-centralizing design feature.

For 2014 the Kawasaki KX250F receives an array of upgrades for the new model year, while the KX450F gets a pair of slimmer stock handgrips and new graphics. We got a chance to swing a leg over both machines as part of a two-day media event at Competitive Edge MX Park in Hesperia, California.

Kawasaki’s motocross lineup is fairly fresh, so we expected only mild updates for the 2014 KX models. But the Team Green engineers were quite busy in the off-season, cramming in several revisions to the popular KX250F and some milder tweaks to the venerable 450F.