Cranks for a bicycle, like many components, differ for different types of bicycles and are combined in different ways with different classes, even within the same type. The main two types of connecting rods are collapsible and non-collapsible. The one-piece crankset is used on budget bikes. In it, it is impossible to disconnect the stars of the system from the right leg. In more expensive collapsible systems, it is possible to change any sprocket as it wears out. Different disciplines use bicycle cranks with a different set of sprockets and a different number of teeth. If you decide to buy a connecting rod for a bicycle, pay attention to the way it is attached to the carriage (on a wedge, on a crank, Oktalinck, etc.). The strength and weight of the connecting rods depends on the material from which they are made. The lowest level is the steel connecting rods, as they are the heaviest and least durable. Titanium and carbon cranks are lightweight and have good durability, but are quite expensive and are used primarily by professional cyclists. The widest range of manufacturers is represented by aluminum connecting rods. Bicycle cranks can have stars with a different set of teeth, for example, the third sprocket can be from 42 to 48 teeth (for mtb), this will change the gear ratio between the stars of the system and the cassette, adjust the load on the cyclist. We always recommend that you consult with a specialist before choosing your cranks, who will take into account all the bindings and combinations with the crossovers installed on your bike.