Question: Do all CB1100 have the same size handlebars? If so what size are they?
If you mean the outside diameter, yes, they are the common 7/8" size.
Nearly all foreign motorcycles are 7/8 diameter or 22mm.
Most American Bikes are 1 inch bars and some Japanese cruisers are also 1 inch bars.
2014 CB1100, 1981 KZ440 LTD, 1993 Yamaha XJ600 Seca, 1994 Yamaha XJ600 Seca