Re: Helmet Lock
This is a much more elegant solution but many years ago I had a helmet stolen off my bike. It had been locked to the bike with a device that secured the D rings. The D rings were still there, the thieves had simply cut the nylon strap. I don't know if there's a market for a helmet that lacks its D rings or if it can even be repaired and then used, or if it was just stolen for spite, but in any case, I was out a helmet. I'd not use such a device again, unless the bike was parked where I could see it.
If I was using such a device I'd place the helmet over the mirror all the time (rain mode). I once saw a smoker drop his ashes into an inverted helmet that was hanging by its chinstrap from a friend's handlebars. His buddies thought it was quite humorous until they discovered the payback that resulted. But that was the wrong thing to do, I'm sorry for it, and I wouldn't do it again.