Why won't your pedals fit into your bmx?

Answer 1

First off pedals are side-specific, one will only go on the right side and one will only go on the left side. Pedals are often stamped with a R and a L to tell you which side of the bike it's supposed to fit on. The left side pedal has a reverse thread and will only go in if turned counter-clockwise. Apart from that there are two resonably common standards, 9/16" and 1/2" - and the wrong one won't fit.