In between crank and pedal、the contacting point there isもmaximum stress . To reduce the stress need to increase the areaオブtheシャフト. So it canbetaperedアフターpassingよりpoint . Ifない、weightオブthe crank will increase and it canbecaused to increase theコストand finally need to右盛り上がるcyclingパワー。
翻訳されて、しばらくお待ちください..
