If you talk to them in person, it should be to get an idea of what they'll do, which may or may not have something to do with what's legal.
If you want legal advice, ask a lawyer with experience in the relevant area.
Probably they will verify that the bike is yours, and retrieve it, or they will say that they don't have the resources.
Are people imagining that the police will say that you can go take the bike, but then turn around and arrest you for theft?
Of course, if the police tell you "finders keepers; it's in the Constitution", then you can seek legal advice.
Police don’t usually investigate petty crimes.
People are imagining the police will tell you that you can't steal it back, when legally you can.
After all, it's the police's job to keep the peace. And things are more peaceful if I'm not busting up thieves' hideouts all guns blazing like Rambo.
Entrapment is reserved for the police going above and beyond, eg "sell me meth or I'll kill your dog" where it can be argued that the entrapped normally would not do the crime.
I still wouldn’t be very excited to try this defense in court.
No, this is about on duty police in uniform saying it's okay.
Working with that suspicion, especially given that this is HN, police saying "don't go steal it back" might still be very good advice, regardless of legal right.
For example (referring back to a scenario earlier in thread), I'm imagining a techbro crew, all jumping into one of their Teslas, and rolling up on misguided urban youth turf.
There's already a lot of misunderstanding and animosity, both ways, between stereotypes. And someone's attempt at "show of force" just escalated it. So, who will escalate the stupid further, and stab or draw a gun first.