I had never heard of tire bells until this morning when I saw this ad on SF CL outed on bikeforums:
To activate the bell, you yank on the pull cord (which you can just barely see dangling behind the frame), which puts the bell's wheel in contact with the top of the tire.
Someone mentioned in a thread about this bike that some companies still make tire bells. Sure enough, I found one on Amazon (where else?):
I'm sure it would be a good way to scare the bejeebers out of pedestrians standing in the DBL. :-) Note the reviews though. It doesn't seem to be well put together...
Wow. Interesting idea but painfully executed.
I bought one a couple of years ago but never installed it. It's pretty cool but heavy and clunky. It'd be great for CCM and such. If I built up a dedicated beach cruiser I'd certainly make it part of the build. Now it sits in a box with my Airzound on a shelf in my bike shop.
I have a couple of those. They do work well; of course you have to be moving to use it. The sound is very much like an old telephone, and is considerably louder than the ping type.