I also have a Bianchi where the rear wheel is practically touching the seat tube. You need to take the air out of the rear to get the wheel off. I remember reading in a bicycle book from the library that the length of the chainstays indicates the type of bike. I think you measure this by going from the middle of the crank to the rear axle. Also, it doesn't hurt to take other measurements like wheelbase and bottombracket height.