Being fit for a bike is not the same thing as being fit, which will not necessarily have a bike involved. Most bike stores have ignorant staff, or they want to steer you towards the stock they have. Some do have competent staff, but it gets real difficult with all the different styles of riding, bikes, physical issues, etc...
Check the results yourself, you can try this road calculator, french fit is the one I use.
http://www.competitivecyclist.com/za...der=M&units=in