given that Adric has probably never seen a bicycle before, there are two possible readings of this ‘diversion’ he sets up:
1) he’s smart enough to figure out what a bike is and how to plausibly fake an accident with one
2) he has no clue what a bike is and is just pretending to be trapped underneath this weird wheely frame thing he’s found because HE’S confused by it so it’ll probably confuse the police