I take my helmet with me as well. If you have a Sena, or helmet-mounted camera, than it would be a hassle to have to continually take those off your helmet. If I was going to leave my helmet locked to my bike, I would get a cable lock (decent thickness - not those teeny skinny ones) and run it through the opening on my full face helmet and lock to the bike (wouldn't work well with a 3/4 or half helmet). The bike-mounted locks seem to only lock your helmet via the d-ring, so anyone can just cut the strap (i know, a helmet with a cut strap is not practical, but I've read stories of follks that have lost their helmets this way). Anyways, hope you can find a good solution.