We watched intently, before the supercross season even kicked off, as the Joe Gibbs Racing squad started work on the brand-new 2010 Yamaha YZ450F ("Top Secret SX Testing: Birth Of A Supercross Bike," April 2010) and initiated the craft of turning it into a full-fledged race machine for the highest level. For the Outdoor bike they worked through the supercross season and even during the planning and preparation period for the Lucas Oil Outdoor Nationals, since an Outdoor machine is a whole different animal than its nocturnal indoor brother.Jealous as well as curious, we were, knowing the inner workings at the JGR shop and seeing the stage performance of the machine. But what the bike was like to ride, we could only wonder as we stood staring at it at the JGR rig just before the first Outdoor National at Hangtown. Since JGR is a little different than your typical factory team, where getting a test ride on a works bike (even though they are production-rule-based) could require months of planning, a lot of secrecy and the even more common flat-out cancelation, we just asked, "Sure would like to ride that Josh Grant bike, you know?"Team manager Jeremy Albrecht responded, "OK, meet Josh and Alex (Ewing, Josh's mechanic) next week at Milestone where he's going to practice. You can ride it there."Now the bike we rode was Josh's practice bike. It was pretty stinking close to a full-on racer, just built up with a little less of the extremely expensive titanium and maybe slightly less of the go-for-broke tune on the engine. The motor still runs hard enough to have only a 10-hour life span, and the suspension was exactly the same as the race bike. At Grant's level he has to practice on top-flight equipment to be on his game.The practice bike comes out of a clean white van, not a factory hauler. It isn't shined to the hilt like the race bike is weekend in and weekend out, but try telling that to Alex who spent eight hours the night before getting the bike ready for a practice day, since some old, fat magazine editor was going to ride it and take a few pictures. It still requires a good warm-up and it is still on the clock when it is running, even with said editor flogging it at half-speed. The good thing about this bike was that Josh and I are of similar size, so his layout was just about perfect, save for a slight clutch lever engagement point adjustment. Everything else on the bike was exactly where I have it on the YZ450F I have been riding.But there were a few big differences, and it started in the power department. This bike, of course, has a lot of power, and it starts right on the bottom, lower even than stock. It is a lot more deliberate than the stocker but is smoother and does not have a step or hit in power like the stocker can at the crack of the throttle. This bike just has so much boost you can have the hit anytime you want it simply by cranking the throttle. I was revving the bike in every gear and taking my time to shift it on my first few laps, but when I pulled back off the track Alex told me, "Bang shifts as fast as you can; don't rev it, just shift."Well, that was a whole new experience on the Dean Miller-tuned engine, and it worked. It was a little deceiving since it revved so well, but if you just hammer the shifts, the JGR YZ-F pulls even harder and goes even faster. Grant likes a lot of top-end, and this bike has it. But it pulls so hard that shifting is the key to speed and traction, plus it is easier on your brain. Just shift. It does not take long to get into fifth through the works transmission inside the cases, which wasn't noticeable by way of ratios. But then I wasn't really ever shifting down below third gear either, even on the tight corners that require second on my stock machine. This shows two things: Lots of power and high corner speed.