Crank description: Crank: 170MM Material: AL6061 aluminum alloy Compatible: Single/Triple chainring; 7/8/9/10S chainring Specifications: BCD: 104mm ,related holes distance: 74mm Weight: about 637g Color: Black/Red/Gold/Blue/Purple Advantages: the use of AL6061 aluminum alloy, light weight, appearance and fashion, very cool, axial strength, strong compatibility Chainring description: Brand: SNAIL Type: Single speed (circular disc / oval disc) Material: 7075-T6 aerospace aluminum alloy Compatible with 8,9,10,11 speed chain Color: Black/Red/Gold/Blue/Purple Thickness: 4MM BCD: 104MM Size:32T, 34T, 36T,38T,40T,42T Shape: Round, Oval Round Weight: about (38g)/32t,(50g)/34t,(57g)/36t,(70g)/38t(88g)/40T(102g)/42T Oval Weight: about (40g)/32t,(49g)/34t,(59g)/36t Bottom Bracket description: Can fit.