Even if you don't follow dirtbike racing, you've probably taken note of Ryan Dungey's recent successes on the new KTM 450 SX-F Factory Edition. In his first season "riding orange," Dungey has given the Austrian manufacturer its first 450cc wins indoors and out, and as this is written looks well on his way to wrapping up the 2012 AMA Motocross Championship. Thing is, the 450 FE isn't really new—it's based on the 500 EXC, a lowly single-cam enduro that works so well, even KTM race boss Stefan Everts (who championed the high-tech 350 SX-F) signed off on using it as a starting point for a new 450cc motocrosser. The 500 EXC is what all tuners dream of: a "fast tractor." It chugs down low, seemingly creating traction where there is none, yet is fully capable of screaming across the desert at warp-speed. On top of all that it's street-legal, so you can ride it to the trailhead. Used to be there were the Big Four Japanese manufacturers and everybody else. Now, offroad at least, KTM is making it the Big Five!