I did this for my wife and it wasn't a big deal. Like most said, you will need new a flat handlebar, shifters, brake levers (unless they are an integral part of the shifters) and a new front derailleur; as mentioned the Shimano flat bar components are designed to do this and can usually be identified by an "R" in the model number. Here is a link to my blog that shows what I did..http://onespeedbiker.blogspot.com/20...onversion.html