I dont' know what size bike I need. I am about 5'9". Correct me if I'm wrong but I believe an 18" - 19" would fit. I have looked every day on Craigslist. When I see a FS that looks decent even close to my price range I google the make to see how the reviews are. Not sure about some of the brands I see. I have heard the names Specialized, Giant, Gary Fisher, Cannondale. But when they start throwing others at me like Kona, Diamondback, Motobecane, I don't know if they are good or not.