Ok monkies. I've been racing DH the last couple years and will continue to do some select races and riding. I have a santa cruz blur 4x that is my xc/trail bike. It's a lot of fun, especially when the trail gets vertical and tight turns, etc.! It's heavy though at 30 lbs. for a 4 inch bike. I've gotten more serious about my fitness lately (riding a road bike, getting my diet in line, did my first xc race in 20 years last week - got my azz handed to me by the way). I've been thinking about getting a carbon hardtail - looking at the Trek 9.7 or possibly a superfly 29er. I'm confused between wanting a 26 or 29er at this point, but have access to ride both bikes and that is my plan. My big question is will the hardtail wreck my back? I seem to always have back pain in the beginning of the season until I get more used to riding. Long rides bother it some too (longer then 2 hours). Will the carbon help some with back issues? I turn 40 in a couple weeks just for reference, but sure don't feel a day over 27 - after 11am anyway:biggrin: Keep in mind I have a 4 inch trailbike, a DH bike, roadbike, and even a slalom bike so this rig will be primarily for xc races and training. Thanks for the feedback.