Bicycle Hollow Shaft BB MEROCA (BB Twist - Ceramic Bearing)

Bicycle Hollow Shaft BB MEROCA (BB Twist - Ceramic Bearing)
colors: black , red 

"BB" is the colloquial name for a bicycle's bottom bracket, a part that connects the crank to the frame and allows the drivetrain to rotate smoothly. This term refers to a screw-in type bottom bracket system, commonly found on traditional or affordable bicycles, as opposed to the more modern press-fit system.
Function of the bottom bracket (BB)
Drivetrain connection: Connects the crank (to the pedals) directly to the frame.
Power transmission: Is the central part that receives the pedaling force from your foot, then transmits this force through the chain to the rear wheel to move the bike.
Reduces friction: Contains bearings that allow the crank to rotate freely and limit friction, making cycling more efficient.