Where is a bottom bracket on a bmx bike?

Answer 1

Installing a mid bottom bracket is very simple. All you do is tap both bearings into both side of the frame evenly, they do not have threads or anything like that its just simple pressure, don't hit it to hard though because you could crush the bearings.

Answer 2

On the most common bicycles the bottom bracket is the bearing assembly that the crank arms and the pedals turn in.