Yamaha motocross bikes scored impressive wins in X Games 16 in Los Angeles, Calif., as well as in OMA Nationals competition in Millville, Minn. over the long July 29-Aug. 1 weekend.Aboard their YZ450Fs, Joe Gibbs Racing’s Josh Grant earned a Gold medal and teammate Justin Brayton a Silver medal in Super X competition at the L.A. Memorial Coliseum, while Nate Adams took a Bronze medal in Freestyle at the Coliseum and a Silver medal in Speed and Style at the Staples Center on his YZ250 two-stroke.Meanwhile, halfway across the country in OMA competition in Millville, Minn., AmPro Yamaha’s Paul Whibley took his third consecutive OMA Nationals win on his 2010 YZ450F.The 16th annual summer X Games offered plenty of motorcycle excitement. On Thursday, Yamaha riders Grant and Brayton, along with Ivan Tedesco and Dan Reardon, lined up for the supercross-style Super X event, but it was rival Josh Hansen who took the early lead. Hansen quickly built a gap and looked to have the race under control, but he unexpectedly slowed and first Grant, and then Brayton, were able to power their Yamahas ahead.Though their rival eventually regrouped to grab a podium position, Grant and Brayton were rewarded with their coveted X Games medals, with Tedesco and Reardon not far behind in fourth and fifth places, respectively. Adams likewise earned his Freestyle medal on Thursday, then followed up with his Speed and Style medal in the very last X Games event on Sunday.Over in Minnesota, Sunday’s grueling OMA Nationals pro race used a lengthy section of woods, together with a good portion of the famed Millville motocross track. Conditions were ideal, thanks to rain earlier in the week, and Whibley harnessed the power of his new YZ450F to get a great start, leading the event from flag to flag.In fact, Whibley and his YZ proved simply untouchable in the combination of tight woods and wide-open motocross track. After forging an early lead, he was able to keep tabs on the competition throughout the event, including during a required mid-race refueling stop, and emerged not only with the win, but the OMA Nationals points lead in the process.