There's, as usual, a hint of apple bashing on most of these threads but in reality -
- once the airtag has left your location it takes 3 days to start making a noise
- the anti-stalking stuff isn't instant either, it's only if the airtag is travelling with you for a prolonged amount of time
- it's not GPS and isn't designed to be
they're very cheap and in the real world if someone nicks your bike they are likely to ride away and then store it, or throw it in a van and drive off. the idea behind the airtag is during the theft they're going to be more concerned about getting away with the bike than searching for an airtag, throughout that period you'll get pings of locations
by the time the airtag warns them that it's nearby or starts making a noise they will likely have stopped and started stripping the bike or checking over what they've got anyway - but hopefully you will then have a "last known location" which will be handy for the police
for the cost of them chucking one inside the frame where it's not immediately visible (or those bizarre mucoff valves that put the airtag inside your tyre for you to destroy on a rock drop lol) - at least offers a slight chance that you could follow someone who nicked it outside a shop while you were getting a sandwich, or get a rough "last known location" after a theft
the visible mounts (under water bottle, seat etc..) are pointless really