In the first scene the bikes have platform pedals, but when you see them again they are different.
At about 1 hr 1 min, the BMX'rs are racing along a veranda when they pass a woman in a green and white outfit pushing a stroller. A few seconds later they pass they same woman and stroller coming out of a bookshop.
When the bike is seen going down the water slide, the pedal on the underside has been removed.