The concept of HOLLOWTECH II technology is focused on producing a superior crankset which will maximize a rider’s power transfer. The rigidity of the crankset ensures pedaling efficiency while its weight, a key element of the crankset, you want light, aids in cycling longer distances over which the rider needs to pedal more. Naturally, SHIMANO strove for the optimum balance between the conflicting needs of stiffness while producing a lightweight crank.