Ach, the Triplets of Belleville is PG-13.

A bicycle Parade with decorated bikes for those with and decorated selves for those without? Maybe podium placements for the best ideas?

Maybe some sort of bicycle "race" where maybe they could stop at stations along the way and pick up a card with points. Placements to those whose cards equal the most points?

Or a scavenger hunt where you must find things that begin with the letters to spell something bicycley, like, um, 'bicycle' or 'tour' or what have you, length of the word depending on the age group?