Which bike under 500 (maybe a little over but between 500-600) should i buy? I have a trek 3900 and its too small, its a alpha, older model, and its just gotten to small for me. Please post suggestions, not just brands. I'm REALLY REALLY looking for a bike that has disc brakes, that would be really nice as well. I'll be doing a lot of trail riding, and mountain biking, but i can't decide whether to get a Hard tail or a Full suspension bike. Please post your suggestion, I'll greatly appreciate it.