On 7/10/2020 5:00 PM, bob prohaska wrote:
A question posed to the New Scientist's 4 July issue posits
that multi-seat bikes have a total weight advantage over
solo bikes (per seat), asking at what seat count the weight
advantage per seat fades away.

Initially, I thought the premise of the question mistaken,
but now I'm curious: Is it true that a modern tandem weighs
less than two solo bikes of the same total carrying capacity?

The illustration that accompanied the question is of a triple,
which I've never seen anywhere in the wild and was probably
chosen for its attention getting value. It's on page 56, alas
no weblink is offered.

Thanks for reading,

bob prohaska

I don't know about triples, but for our tandem (i.e. double), I think
it's certainly true.

This is a steel bike, oversized Reynolds 531 tubing, lugless brazed
construction done in 1979 and no components are particularly
lightweight. It weighs about 39 pounds with fenders, dynamo lighting,
heavy wheels and 32mm tires. In those days I don't think a single bike
of its quality would have weighed less than 20 pounds.

There's also this authoritative reference, by Tony Pranses:

================================================== ===============

SHOVELIN' COAL

There are those who think the tandem is the instrument sublime
For the serious cycle-tourist, and the man concerned with time.
It has drive and rolls much faster as it gobbles up the track,
But it's quite another matter to the guy who sits in back...shovelin'
coal.

But just look at the advantages with twice the power at hand,
And half the wind resistance as it travels o'er the land.
The weight is less than double. This alone gives peace of mind.
But it's still another matter to the guy who sits behind...shovelin'
coal.

Yes, the man up front is master. It is he who shifts the gears.
He decides when brakes are needed, and on top of this he steers.
He can go the wrong direction and wind up in Timbuktu;
But refuses any protest from the guy who's number two...shovelin' coal.

It's just like a locomotive, with the front man engineer,
He sits back and shouts instructions to the fireman in the rear.
It's the way to run a railroad. With a bike it's not so sweet
To the sweating, swearing fellow on the secondary seat...shovelin' coal.

True, the pilots work the throttles while their partners work the flaps.
They are barely more than slaves -- a society of saps.
Co-pilots do the labor. They are not supposed to feel.
It's likewise with the suckers above the rearward wheel...shovelin'
coal.

His view ahead is blank and to peek would be a sin;
So he can't see where he's going -- only places where he's been.
He would love to lean to starboard when to port they make a turn,
But such pleasure is verboten to the fellow in the stern...shovelin'
coal.

Yet there will be retribution on some future day in hell,
When all tandem frames have melted, and the tandem leaders yell.
In agony they writhe, and some mercy they request;
But the back men just keep doing the thing they've done the
best...shovelin' coal.

================================================== ===========

Note "The weight is less than double" in the second stanza. Case closed!
;-)

--
- Frank Krygowski