vivi_roc

Can anyone tell me what's the different?

thanks

mtbikerinpa

Cotterless crank is the generic for all types that do not have a cottering wedge bolt retaining the arm onto the bottom bracket. There are a couple of varieties of square-taper spindles however. ISO taper is one of them. To cross types is frowned upon and is generally detrimental to the parts, so it is good to know which is which.