i don't take my helmet off as i wear a modular.. if i do take it off, i hook my keys to the d ring. if i leave it locked to my bike, somebody will piss in it. but i have been know at times to leave it on the bike in which case it fits nicely over my mirrow. i've never had a helmet fall off my bike. But if i was the type, a nice little hook in a convient place would probably work. it should be machined brass or stainless and cost less than $10 delivered for me to buy it.
2012 VSTROM ADV 650