So what's the plan with the 450? New class for someone to race?
The only experience I have with the YZ 450 suspension is the 2009 stuff that's on my 2006 YZ 250. A worn front axle made this year's GP season interesting and difficult. This year's races were basically all mudders and with the wet weather I rode the 250 almost exclusively at the races. I thought I was just old and loosing my balance and didn't discover the real problem until I actually had a bearing go bad. With the new bearings in the wheel I placed the axle through to find there was still a lot of play. But with the axle mounted and tightened to specs the play wasn't detectable, the front wheel seemed solid. Solid that is until I tried to ride and the front wheel was still climbing out of every rut, tracking with every surface irregularity and generally trying to throw me over the bars (that happened way too much this year). With a new axle installed, I have a new bike that sure is easy to ride when it goes where I want it to. I'm still regaining confidence riding but I believe riding with an unruly front end this year actually made me a better rider. It's good to know that I'm not just old and totally loosing it anyway.
The scorched and scored side of the axle is where the bearing went bad but the other end is just as worn. The 2009 (next design fork) 450 axle is shorter than the same diameter 2006 250 axle that it replaced. That along with a stronger Honda front brake and rotor may have contributed the axle wear. The new YZ 450F has a larger diameter axle and bearings. So maybe Yamaha also dicovered that there was a problem?
Anyway, now that my old, updated 2006 YZ 250, better than the 2016 250 is fixed, it's probably the best handling bike I've ever had. Even more fun now than my 2006 YZ 125 and I didn't think that was possible.