I know that this has been discussed on the forum before, but the search function doesn't seem to be working. There are a few devices/guides available that clamp on to the seat tube that keep the chain from jumping off the inner chain ring on down shifts. I'm not sure what they're called or where to find one.

Thanks,
Dan

Although we don't use one, if we did it would be this model:
http://www.gvtc.com/~ngear

Rich Shapiro (Gear-To-Go Tandems) sells them about as cheap as anyone else I've ever seen.
http://www.gtgtandems.com/parts/guides.html

Of course, other tandem speciality dealers carry them as well and you'll find them elsewhere, e.g., catalogs, etailers, etc...

Third Eye performs the same function, but uses a "one-size-fits-all" design with a hose clamp that nests inside the one-piece plastic chain guide.
http://www.excelsports.com/new.asp?page=8&description=Chain+Watcher&vendorCode=Thirdeye&major=6&minor=8

Thanks! That's exactly what I was looking for.

The Jump Stop by N Gear is the best one out there, way better than the Third Eye, the Third Eye is sort of cheesy and lacks the fine adjustments you get in the N Gear Jump Stop. They can and will save your paint & road side headaches. Yor best defence is a... properly tuned front derailleur & the Jump Stop for peace of mind.:D Pic of the Jump stop below.

Take Care,:)
Bill G