I have been riding my '06 450 XC for quite some time now. I love the bike, and made a few changes to enjoy it even more. When I first got the bike, I rode it with the 8.0 rear spring and felt that it handled good. After getting an 8.8 spring for my weight, 180lbs, I was able to set the sag to perfect textbook numbers, 40mm free sag, 115 race sag., 6mm preload on the spring. I left the forks at the first line from the top of the triples, compression clickers are in the stock location, rebound is set 3 out front and 3 out (faster) rear. The bike works great everywhere, except for flat hard packed turns. I ride a particular track which half of the turns are flat 90* sweepers and the other half 180* sweepers. The surface is white sand dust over hard limerock. The only issue with the bike I am having is that about halfway through the turn, the rear end wants to step out quickly. The front end never washes, although sometimes it wants to steer wide. If I get on the gas at the apex, the rear end steps out flat track style! If I really weight the outside peg, it seems a little better. If I sit farther back, the rear sticks, but it understeers across from the inside to the outside. Some other things about the bike to consider: IRC IXO5H hard pack tires front and rear, 13 lbs each. Stock front forks, XC has .42's. bike is perfect everywhere else on the track. I only bring this up because my buddy got a new RMZ 250f, I rode his bike on the same track and it turns on a dime! His RMZ sticks to whatever line you put it on, and stays there. The rear stays planted, he has Dunlop 742fa/756 combo. I guess what i am asking is how can you help make my rear stay planted? Could it be the tires or is it the bike balance? Rear end stepping out seems like it would be the rear unweighting at some point during the corner, it does seem worse when I get farther forward. I would imagine it would get even worse if I raised the forks in the clamps. Any suggestions would be helpful!