Originally Posted by
bulgie
Yes I have heard that story, maybe apochryphal. The version I heard was the first Paramount tandems were made for the Rome Olympics (1960), and the only tandem event at the Oly's was Match Sprint. That's essentially a 10-second event, the part of it that matters. So comfort for long miles is not in the list of requirements.
Then (the story goes) they used the same jig made for the 1960 Oly bike to make P'mounts for sale through dealers.
I guess that story might be laughably wrong if the 1940s tandem you showed is really a Paramount. I guess it doesn't matter what they called it; the important fact is they had the ability to make tandems much earlier than 1960. The jig doesn't care if it's a Superior, Town & Country, or a Paramount.
The Chicago folks should know the Schwinn history, right? (Skip, are you out there?) Maybe they know when the first tandem popped up.
In the meantime, a search on Flickr did pull up an early Schwinn tandem, advertised as the first Schwinn tandem, and built in 1948. This is from the photostream of "bobbiker" ... Bob F?
the photo can be found
here.
It's got the same sort of extra stays, plus a diagonal tube in the front triangle only. One of the photos says it was for Jack Simes III and Jack Heid. I recognize the name of Mr. Simes, but don't know if he was one of those powerful sprinters.
Not directly related, but one of the shops in St. Louis (the old A-1 shop, now "Billy Goat Cycles") has a quad built by Ray Sr. (who started A-1). It's got 3 sets of stays too, but the middle set extends into a diagonal tube (with no top tube), so it makes sense. Being a quad, it must have been flexing all over the place. Ray did use a middle horizontal tube in each "triangle" for some extra torsional stiffness. It would be interesting to know just much that frame was flexing, though! With the modest braking power available, I don't suppose anyone was too interested in seeing how fast they could go.
Originally Posted by
bulgie
The story could still be true, if they used a single-bike jig (or no jig at all) to make tandems previously, which is do-able, just inefficient. And only made a dedicated tandem jig in the buildup for the '60 Oly's. Certainly you don't need a jig to make a tandem; The Taylor bothers (Jack Taylor) made hundreds, maybe thousands? with just tubes laid on firebricks, with a heavy weight laid on to to hold the tubes down! Alignment checked by holding the frame up towards the window and squinting.
Yes and yes, all of the above. Except any stiffening of the rear triangle from those mid-stays on the 1940s bike is not going to be detectable, they are poorly placed to resist the stresses on a rear triangle. If those stays continued all the way up like on a mixte or on the red Paramount that started this thread, then they can "pull their weight" so to speak. But the ones on the '40s bike are just extra ground-hugging mass IMHO.
(back to Flickr...) Jamie Swan has a shot of a lovely 1969 Jack Taylor tandem, and it's got a big ovalized "boob" tube (is that the term?), along with proper diagonal tubes. Were they the only ones who could get specialized tandem tubing? Kinda strange that Schwinn wasn't using it, but maybe that's an indication of how out of touch they were with the rest of the world? Although.. they must have been in contact with Reynolds and could have asked.
the photo can be found
here.
Originally Posted by
bulgie
EDIT: ooh and notice the tiny chainrings used for the timing chain on the '40s bike; definitely suboptimal for a sprint bike. Chain tension is inversely proportional to chainring size, all else being equal, so if you used rings twice as large, you'd have literally half the chain tension from the cap'n sprinting. There's a lot of frame flex caused by that chain tension, due to the chain being offset from the center-plane of the frame. It's not threoretical; you can feel it underfoot, and even see it by eye: the lower run of the chain sags visibly when cap'n applies force to the pedal, enough sometimes to cause the chain to derail, which can cause a crash. That type of flex is the main reason why some bottom tubes are oval instead of round.
Even if it didn't flex the frame, having double the chain tension can result in the chain snapping. I've seen it, happened right in front of me when Nelson Vails and Scott Berryman were on a Team USA sprint tandem. When they jumped, the timing chain broke. That's the captain's pedal force only BTW, stoker's strength doesn't go through the timing chain at all. So Vails broke that chain all by himself. And it wasn't a tiny chainring, it was Campy 144 BCD, so we know it was at least a 41t, probably bigger. Him on a chainring half as big would have sent shrapnel into the bleachers!
I've seen Nelson on the Ride the Rockies ride in 2004. He was out of his prime form, but his legs were still massive! I pity any chain that he is putting power through!
Maybe the small rings were for the longer events with riders with more ordinary legs?
Steve in Peoria (no worries about me snapping chains)