Where do you live? Even in relatively flat places like NYC or Boston, where singlespeed and fixed-gear riding are very popular, I think most of us would recommend that for your *only* bike, you want to start with gears. A frame that will be easy to convert is a great idea, because by the time you really want to play with singlespeed or fixed, you'll probably want another bike anyway for your geared biking and you'll be able to convert your old one to fixed and buy the bike you really want now that you've got more experience for your new geared one. (Although, for now, even a frame that's tough to convert would be a fine choice, for the same reason: when you buy your next bike, THAT one could be the single.)

Yes, as Bacciagalupe says, what you want is a frame with horizontal dropouts, ideally with a derailleur hanger, as shown here: http://www.sheldonbrown.com/singlespeed.html#vertical . Note that "horizontal" dropouts are actually slanted, unlike track dropouts, which are truly horizontal and open the "wrong way" from what you want.

You're probably going to have a difficult time finding horizontal dropouts in a *new* inexpensive bike, but you'll have a very easy time finding them inexpensively in good-quality used bikes from the 70's and 80's, and some from the early 90's. I would definitely recommend going to a shop that sells good-quality used bikes or enlisting a bike-savvy friend to help you search Craig's List and come with you to "kick the tires" and check the fit on your visits to the sellers.

If you're willing to drop some more cash on this bike, then by all means order a new "more expensive" bike with a frame that has horizontal dropouts, such as the excellent Surly Cross Check -- http://surlybikes.com/frames/cross_check_frame .

If you have more questions, we should probably move this discussion to the Singlespeed and Fixed Gear forum -- you'll get loads of responses there!


Dan