Hybrid city bike commuter bike type ladies wheel size 28 inch frame material aluminium frame alloy 6061 aluminium bike frame sizes cm 45 50 cm frame sizes m s brakes black comp tx121 rear derailleur shimano nexus number of gears 8 braking systems coaster brake rim brakes crankset prowheel cassette shimano chain kmc z610 rims schrmann euroline tyres schwalbe silento stem aluminium handlebars moon cruiser aluminium saddle brooks flyer