Stolen bikes

Yeah I know it is a problem, but they are just kids so all that will happen is they get a caution and then want to put some nice holes in my friend or me.

I understand that, Neil, but you don't have a gentlemen's agreement with them not to report it, do you? If they attack you following your reporting of them, the police should be really on their case. Also, another possible outcome is that they'll be known to police and possibly deterred from stealing bikes.

Sorry if I sound naïve, but I'm afraid I don't have first-hand experience of how this sort of thing works out in practice.