installed a new double crankset and sks pedal...before installing the crank i find it necessary to overhaul the bb. as i was turning the bb i feel it is so gritty, just found out that there is an opening on the non-drive side which accumulates dust or sand. after overhauling bb(thanks to youtube bb overhaul) i feel i have a smoother ride today. however i thinks it is necessary to change sealed bb for a consistent smoother ride. also installed clikfix, dropped my plastic cap somewhere.