I think you'd be better off just buying a road bike. Here are some issues: You swap out the flatbars for the drop bars. This means you need to swap out the shifters as well. You'll probably want "brifters" which means different brake levers. So far, no big deal - but, will you get drop down shifters compatible with your front and rear derailleurs? I don't know, but that's a consideration. You want to match the indexing. A bike mechanics can tell you about that. Next, you'll want to swap out tires for a narrower one - probably "25's" and possibly "23's" Will your rims accommodate that? But other than those things, no problem.