I put mine in the trunk when possible, but when it is full I have a lockable carribeaner and hang it from the mirror.

 

It depends where I am. I live in the country and the nearest hardware, gas and other services are in a "bad area" of town. When I go in places there I take my helmet with me. When I go other places or if there are other bikes with hanging helmets I'll leave mine. Kuryakyn has a series of hand grips, the ISO series, one of the options available is a helmet lock. Pretty cool looking, but $85 plus the cost of the grips.

 

I usually don't lock mine, just set it on the seat. But when I leave the bike at work I don't want the helmet sitting there unlocked day after day. I simply hang it on the right bar, and pad lock the d-ring to the mirror. I know a guy could screw out the mirror but he could also cut the helmet strap with a knife. It just makes it so that someone cant grab it in the spur of the moment.

 

I use the D lock that HD makes, attaches to my crash bar. Feel a little safer with that set up. Anyone can break it, just keeps the honest, honest.

 

I use one of the d-lock type locks. It locks around the d-ring on the helmet strap. The lock is bolted to one of the downtubes

 

Kryptonite R4 retractable cable lock. Run the cable down the sleeve of your jacket then through the d-rings on your helmet. Won't deter a determined thief but enough to prevent a grab and run. Small, light and self contained.

http://www.kryptonitelock.com/Produc...=1001&pid=1132

 

My helmet has been sitting on the bike for 20+ years of riding. The only time one was stolen was when i went to a redneck country bar.

 

I stick mine in the TourPak and lock it.

 

We were finishing a ride at the gas station waiting for everyone to come in. About 20 of us. One member had his FF stolen off his bike with a lot of bikers standing around. Still with all the people walking around, didn't notice who took it. No one pays any attention when in a crowd.

Was lucky that the gas station had a crappy 3/4 lying around that he could use to get home.

 

I am not that worried about replacing a helmet. I've got 4 of them. But, when you live in helmet required state then trying to get home without a helmet would be almost impossible. Let alone two people. I lock my helmet so that it's there when I need it.

You guys that say 'the thief better watch out for me' are missing the point. It's not about being able to afford to replace, or if it's full of cooties, or sweat, etc.

I carry a cable lock like I use on my skis. It gets threaded thru my jacket sleeve and the chin bar on the helmet, then thru front wheel or frame. I just want my helmet there when I need it!

I also bought one of the license plate locks that you see at almost all the bike rallys. I think most of the on line catalog stores carry them as well. I bolted it to the right foot peg. I can hang both helmets (hers and mine) on in, away from the pipes and not touching the ground.