Racing bike type unisex geometry classic racing bike frame sizes cm 50 58 62 cm colour black model 2017 frame material aluminium fork material carbon gear system with derailleur number of gears 24 groupset shimano rear derailleur shimano sora derailleur model shimano 3500 front derailleur shimano claris crankset shimano sora front chain wheel teeth 503930 chain kmc z72 braking system rim brakes brakes tektro wheel size 28 inch ty