just post up ten million craigslist ads with his home address and phone number on. You're probably not gonna get paid because you let the bike go and now you have no leverage. How much time are you prepared to spend making his life miserable???? how will that impact on yours??? spending an hour a day pissing him off will piss you off for an hour a day because you'll remember why for an hour a day. Smashing his face off the concrete will provide a similar win/lose situation as it's nice to fuck a thief up but it's not nice on the soul knocking peoples teeth out; and you might go to jail on top......
write it off and learn from it. don't waste energy beating yourself and others up about it.