A bicycle lock is a physical security device used on a bicycle to prevent theft. It is generally used to fasten the bicycle to a bicycle stand or other immovable object.
Confine with a chain
(chain) connect or arrange into a chain by linking
irons: metal shackles; for hands or legs
(chain) a series of things depending on each other as if linked together; "the chain of command"; "a complicated concatenation of circumstances"
Fasten or secure with a chain
Never enough
Bike locks "stored" on a grate. Local biker couriers ("motoboys") who always park nearby leave the locks there so that they don't need to carry it around.
Rua Boa Vista (Largo Sao Bento), Sao Paulo, Brazil.
Locked
Heavy duty chains and padlocks seem to be de rigueur in New York. I didn't see a single U-lock. And apparently they come in handy for fisticuffs between couriers.