Vintage tandems - why so evil ?

- Bob - writes:

I've seen a few posts indicating that vintage (70's, early 80's)
tandems are not a good idea.

What are the issues ? Is it frame flex causing drive train issues?
Other problems ?

IMHO, one of the main problems with these tandems is insufficient
braking power, especially on steep downhill runs. Here in San Diego
we had a couple on a purpose-built jack taylor tandem lose both front
and rear centerpull brakes on a very steep downhill. The vintage pads
were dry-rotted and so popped out when asked to deliver unreasonable
stopping power. This is not the type of failure you'd expect to see
on a road bike.

Most tandems today use cantilever or U-brakes at a minimum, and disc
brakes (3-brake tandems) are also very very common.

The things that tended to fail on road bikes, e.g. broken rear spokes,
broken axles, indexed headsets, snapped chains, 2-pawl freewheels, etc.,
tended to fail much more frequently on vintage tandems because in
those days road bike technology was insufficiently robust under the
high stress loads of tandems.

- Don Gillies
San Diego, CA