Racing bike type mens geometry sloping comfort frame sizes xl l s m bike frame sizes cm 49 52 54 56 58 61 cm colour black model 2017 series specialized allez frame material aluminium frame characteristics hydroforming fork material carbon gear system with derailleur number of gears 22 rear derailleur shimano 105 front derailleur shimano 105 gear shift brake lever shimano 105 crankset praxis alba 2d front chain wheel teeth 5236 c