Urban bike fork material crmo fork material aluminium type mens wheel size 28 inch model 2015 frame material aluminium frame alloy 6061 aluminium frame geometry diamond bike frame sizes cm 60 55 53 57 cm frame sizes l xl colour black brake type u brakes brakes tektro r315 gear system internally geared hub igh rear derailleur sram automatix number of gears 2 braking system rim brakes rear chain wheel teeth 17 front chain wheel teeth