Handlebars come in 2 variations: 25.4 mm and 31.8 mm stem clamp diameter. All 2017 bike models come stock with 31.8 mm stem clamp diameter. If you are changing your handlebars please check the individual product specs to determine the correct stem clamp diameter.
31.8 mm alloy riser bar is 56 cm wide, 25.4 mm bar is 50 cm wide
22.2 mm brake clamp diameter for 25.4 mm; 31.8 mm brake clamp for 31.8 mm bars
31.8 mm is available in 2 colors, 25.4 mm is available in black only