bike, n. — Green’s Dictionary of Slang

bike n.

1. (N.Z. prison) a cigarette, sent from one inmate’s cell to another (only possible when cells are facing each other across a corridor).

2001

D. Looser Boobslang [U. Canterbury D.Phil. thesis] 17/2: bike n. a cigarette containing tobacco, sent from one inmate to another after lock, or when face-to-face contact is not possible.

2. see bicycle n. (2)

In phrases

on one’s bike (adj.)

(N.Z. prison) choosing to divorce one’s partner,living in the free world, while serving one’s sentence; also used of ending a homosexual partnership between two prisoners.

2001

D. Looser Boobslang [U. Canterbury D.Phil. thesis] 18/1: on one’s bike involved in a prison 'divorce', either as a couple comprising an inmate and his or her spouse on the outside, or as two inmates involved in a homosexual relationship.

on the bike (adj.)

(US) of an individual, in trouble; of a place, unpleasant.

1895		Anaconda Standard (MT) 15 Dec. 10/1: ‘Since I blew dis town I’ve been strictly on der bike. Bum? Well, I should say it was bum’.
1895		Anaconda Standard (MT) 15 Dec. 10/1: ‘Dat Helena is on der bike, sure. She’s der bummiest place dat dere is Why, dere ain’t no show fer er moocher dere. dey’s all on der bike’.

SE in slang uses

In phrases

get off one’s bike (v.)

(Aus.) to lose one’s temper.

1972

A. Chipper Aussie Swearers Guide 77: The person involved [...] does his lolly and gets off his bike (i.e. becomes angry).

turn one’s bike around (v.)

an excuse (usu. male) to absent oneself from a group and urinate.

c.2000		personal communication.
2021		Twitter 28 Oct. 🌐 Today in Bognor my stepfather asked if I knew where he could ‘turn my bike around’. A new phrase on me for location of the lavatory.