The concept of Hollowtech II technology is focused on producing a superior crankset which will maximize a riders 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 Hollowtech technology is an ultralightweight hollow crankarm created by Shimano with the companys own proprietary forging technology that also maintains rigidity The addition of Hollowtech II technology integrates the bottom bracket axle with the right crankarm for more stiffness and a weight savings to achieve a highdimensional balance Its outboard bottom bracket bearing system provides better weight distribution and more pedaling stability allowing for more efficient power transfer Key Features Road Model BBRS500 BBType HOLLOWTECH II Threaded BSA BC 137 Threaded BB shell width 68mm Shell diameter BSA BC 137

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