Quote Originally Posted by Biciclista View Post
most people who have bikes with serial numbers do not know this information.
Sorry to sound cold, but that is their problem, not mine. All they have to do is flip the bike over and write it down.

You think those people are going to have the "license" number written down in a safe place but not the serial number?

If I was worried about a custom (presumably) bike without a serial number (a fair number of custom makers stamp a serial number anyway, so your situation is pretty rare) I'd etch an identification into the bottom bracket shell (same place as a serial number) or even drop a laminated piece of paper with my info on it down the seat tube long before I trusted a highly visible and easily removable piece of "id" with theft recovery.