^ if im goign to be leaving the helmet with the bike for a bit, thats what i use. i got a python bike lock. its about 5 feet long. when i had a grab rail i wrapped it around that. now i just wrap it around the frame. since its long you can put it through the sleeves of your jacket too. i mean, if someone wants your shit bad enough, they will get it. but for the casual theif, i think its enough of a deterrant. you dont have to make your shit impenetrable. just harder to steal than the guy parked next to you