You should choose the size of your bike based on your height, as well as your build (arm span and leg length). If you are between sizes, the smaller size will give you a more athletic position, while the larger size will give you a more comfortable position. XS 5'1"-5'5" S 5'5"-5'8" M 5'8"-6'0" L 6'0"-6'3" XL 6'3"-6'7". Comfort-oriented frame geometry with a higher steering socket and a shorter top tube that offers a more upright position than a classic road frame. 6061 T6 aluminum sloping frame with semi-integrated headset. Frame weight, size M:4 lbs. Carbon fork that is more lightweight and offers more precise directional control. A headset 1-1/8" steerer tube makes the steering assembly strong and rigid. Inserts in the fork to fit a pannier rack. Maximum load on the fork:19.8 lbs. Ergonomic aluminum Triban flat handlebars for a better grip and excellent comfort. Grip with integrated fixing ring Handlebar width (axle-to-axle):XS/S/M:560 mm. L / XL :600 mm. Triban forged stem:XS:70 mm S:80 mm M:90 mm L:100 mm XL:110 mm. High-precision, sturdy Micro shift 8-speed shifter inner routine. Very comfortable design:The shifter is easy to operate regardless of hand size. Front Micro shift derailleur and high-precision Micro shift rear derailleur