I realize Ed Rios hasn't made these for years, but in surfing around Amazon today, I came across what appears to be a damn close knock-off of what he used to build. Ordered one just to see how it works.
Amazon.com: Helmet-to-Helmet Intercom Motorcycle Helmet: Automotive
We still have our old Tandem Talk unit, but the microphone wires eventually bit the bullet, and I had never tried to source replacements.
I'll post a review after we try it out.
Ah, Ed Rios . . . he and blonde partner used to ride a Cannondale tandem in the Tucson area and in Ohio.
A blast from the past . . .
Rudy and Kay/zonatandem