The Tandem Talk (http://www.TandemTalk.com
) and the Chatterbox HJC-40 and HJC-50 (http://www.hjc-chatterbox.com/main_static.html
) systems are about the best thing going for use on tandems for teams who have a need or desire for an intercom system. The Tandem Talk is application specific whereas the Chatterbox models seems to work just fine -- BUT -- don't come with headsets that are not ideally suited for bicycle helmets.
As for wire interference, I've never heard any complaints from folks who use the Tandem Talk system, any several of the folks we ride with are very aggressive riders who routinely climb out of the saddle. The Tandem Talk "unit" is placed in the Captain's rear jersey pocket and there's plenty of slack in the Stoker's wire to allow them to ride out of the saddle together or independently without jerking the Stoker's wire or having it tangle with their bars, etc...
Wireless FRS Radios seem to suffer from poor performance at very close range and anything beyond FRS technology gets pretty expensive and relatively larger/heavier... take a look at the bike-to-bike communicators on the Chatterbox Web site and you'll see what I mean. For reference purposes, we've used the HJC-50 and the HJC-90 on our motorcycles but haven't found a need to use them on our tandem.
Last edited by TandemGeek; 01-30-05 at 09:52 PM.