Provided you have taken reasonable steps to find the owner (of which informing the police probably counts), subject to whatever lost & found policy the police have, you will doubtfully get into any trouble holding onto the bike*.
The bike would still be the owners though - they could still ask for it back next year.
I'm sure there's a test for reasonableness though - After how long could you reasonably assume that the bike had been abandoned. There's no stated rule or strong precedent, as far as know.
I'm not a lawyer. Anyone taking this sort of advice to heart from an internet stranger should probably just hand themselves into a police station now and ask for a shoeing,
Provided you have taken reasonable steps to find the owner (of which informing the police probably counts), subject to whatever lost & found policy the police have, you will doubtfully get into any trouble holding onto the bike*.
The bike would still be the owners though - they could still ask for it back next year.
I'm sure there's a test for reasonableness though - After how long could you reasonably assume that the bike had been abandoned. There's no stated rule or strong precedent, as far as know.