Tandem Cycling - Mixte Stayed Tandems

I've got a 1974 Gitane with mixte stays. It's not a full on mixte frame though- it's got a stoker top tube. The mixte stays run from the head tube to the dropouts. I love this bike. I've done short tours on it, taken girls out on it (in fact it was instrumental in getting my current partner to come back to my house on the first date!). But let's face it, the thing's a giant noodle, the crank bearings are french threaded, the steerer is 1", and it's spaced 126mm in the back. That, and it's got a tiny stoker cockpit and 1" seatposts, to boot.

I'm considering going for a brand new custom bike (in a few years -- for now, as a poor grad student, this will have to do). My local framebuilder, Rodriguez, builds excellent tandems, and I would certainly use them. The issue is, I want another tandem with mixte stays! I think they are amazing. R+E tells me that a mixte stayed tandem would be more flexible than a single-lateral bike, and I'm just not sure I believe them. The mixte tubes get material out of the plane of the frame, which seems like it would increase out-of-plane bending stiffness. I know my tandem is a noodle because of the narrow diameter tubing used throughout, and who in their right mind would build a mixte stayed tandem with modern, oversized tandem tubing?

So, my question to you is this: has anybody seen/built/ridden/owned or coveted a mixte stayed bike with modern tubing? or, has anyone compared a noodly 70's tandem with a standard 1 1/8" tubeset with mixte stays to one with a single lateral?

At some point, maybe I'll put some Finite Element Method software to work and figure out the truth, but for now, I'm happy with anecdotes.

P.S. I'm talking about steel here, in both the case of the old floppy and the new custom bike. Natch.

If you use the thin parallel running stays from headtube to rear dropout, have them put some crossbars between the two lateral stays to stiffen up the frame. At least 2 for the pilot and 2 for the stoker. The center of those cross re-inforcing little bars can then be set up to hold water bottle cages if needed.
Suggested that to a friend who had a similar old Gitane and it did inmprove stiffnes for that bike.
With modern oversized tubing it could work out very well and would be a unique retro effect.
Co-Motion used to build a tandem with a tri-lateral tube setup. That included the internal lateral found on most tandems + a pair of thin tubes running parallel from the pilot's seatpost to the rear dropouts.
Just our input.
Pedal on TWOgether!
Rudy and Kay/zonatandem

Here's how Schwinn built their Paramount Mixie Tandem, with steel, natch! They used long small stays for the diagonals at both positions. I have no idea how flexy it might be. It used "Chrome Molybdenum" straight tubing, which was fillet brazed.


Here's Schwinn's significantly less expensive Twinn Sport, which I own. As you can see the diagonal middle tube at the Captain's, and the toptube at the stoker's positions are small diameter 1020 steel tubing. This frame uses a combination of Electro Forging, fillet brazing, and tig welding in its construction.

I've never ridden in the stoker's saddle, but my wife reports the ride is flexy. I don't feel this in the captain's saddle. Her other bike is a very stiff aluminum framed Specialized Hard Rock MTB set up as a hybrid. This might explain the difference in her perception.

Do you have any pictures of your tandem?

But let's face it, the thing's a giant noodle.........The issue is, I want another tandem with mixte stays! I think they are amazing........who in their right mind would build a mixte stayed tandem with modern, oversized tandem tubing?

Huh? Are you listening to yourself?


R+E tells me that a mixte stayed tandem would be more flexible than a single-lateral bike, and I'm just not sure I believe them.

Of course it would be, but it also would be a lot stiffer than your old Gitane.

have them put some crossbars between the two lateral stays to stiffen up the frame. At least 2 for the pilot and 2 for the stoker. The center of those cross re-inforcing little bars can then be set up to hold water bottle cages if needed.

Absolutely, I've thought about this, as bridges would provide shear-coupling and definitely make the stays more effective in flexure. Water bottle mounts on those bridges would also be pretty rad. Also, with 1 1/4" tubing or 1 1/2", how big should those mixte stays be? the usual 1/2" seems like it would look weird with the giant tubes, maybe 5/8" or 3/4"? now I'll definitely have to AutoCAD this thing.



Do you have any pictures of your tandem?

Unfortunately, I haven't had a digital camera for a while. I really should borrow a camera and photograph it soon though. Maybe I'll post some later.
I love that ad you posted, those two young gents on the blue bike must be having a whale of a time!
Mine looks very much like theirs, complete with painfully short stoker cockpit. The Gitane of course, is french, so it's got MAFAC Racers, eccentric BB and a left side timing chain (modern sugino crankset). I have some very silly riser bars with bar ends for the stoker.


Huh? Are you listening to yourself?
Oh, believe me, I know I'm not right in the head, after all, who in their right mind needs 8 (functional) bikes? probably a few of us at BF.

Hey, look at that, I do have a few pictures from a tour last summer.
The bike has since lost the north road bars in favor of risers+bar ends (longer cockpit), and it has new brake levers (Tektro) and bar end shifters (Shimano 8 speed, not that I use the indexing on my 5 speed freewheel). The water bottles have been shifted around a bit, as well. The "help wanted" sign is for those days when I don't have a stoker, but on this trip it caused a problem: we were stopped by the side of the road eating apples and someone pulled over because they thought we needed help!

P.S. I promise none of my other bikes have this many zip-ties! At least the twine wrapped around the stoker top tube I can explain: it's to hold the toe-clips off the ground when I ride it alone.

It is definitely C&V. I like it. Thanks for the pics.

My tandem has dual mixte stays and a stoker top tube. I had ridden a Paramount tandem and I felt it was too noodly, and so I built my frame with dual mixte stays. It's Reynolds 531 tandem tubing and some 4130 tubing for the mixte stays. My friend built a tandem frame with less bracing, and his was noodlier too. The 531 tandem tubing had 1 1/4 downtube and 1 1/8 top tube as well as an oval connector tube. As far as I know, this was the first oversized tubing set that the big tubing manufacturers made. I built the frame in 1980 or so.

In the 1970s most tandems had short wheelbases. Most were around 63 inches.
Schwinn also had tandem with bent rear seattube at that time and they were same-side-drive.
Owned a custom Assenmacher Reynolds 531 (cross-over drive) back in 1977 with a 60 1/4" wheelbase. Achieved that with massive toeclip overlap for pilot and a slightly bent rear seattube. Rear tire had to be deflated to remove the wheel.
However stoker Kay was (and still is) on the short side: 4' 10 3/4". Pilot was/is 5'7".
Even for us it was a snug fit; we wanted a fast/light/maneuverable tandem. Put 64,000 very happy miles on that Assenmacher.
Pedal on TWOgether!
Rudy and Kay/zonatandem

Zonatandem: My brother's Gitane has a curved seat tube, also quite a short wheelbase. It's also got no laterals at all- the thing handles like spaghetti.


My tandem has dual mixte stays and a stoker top tube. I had ridden a Paramount tandem and I felt it was too noodly, and so I built my frame with dual mixte stays. It's Reynolds 531 tandem tubing and some 4130 tubing for the mixte stays. My friend built a tandem frame with less bracing, and his was noodlier too. The 531 tandem tubing had 1 1/4 downtube and 1 1/8 top tube as well as an oval connector tube. As far as I know, this was the first oversized tubing set that the big tubing manufacturers made. I built the frame in 1980 or so.

Sounds excellent. I'd love to see pictures of your frame. I assume it was sufficiently non-noodly? When you say dual mixte stays, do you mean two sets, ie. one set from head tube to stoker BB, another from captain seat cluster to dropouts?

My tandem's only concession to oversized tubing is a 1 1/4 inch bottom tube. I think this little tube is a major source of it's noodliness. A friend of mine has a Le Jeune with a flat plate joining the BB shells; Probably a little stiffer, but good golly, that thing has got to weigh a bit. I think ovalized bottom tubes, as well as wide-ovalized seat/down tubes at the BB are the key to getting frame stiffness and fatigue resistance, especially for tandems and larger riders. Plus you can keep your narrow tube aesthetic (from the side, at least).

Have seen a couple of the 'no lateral' 70s Gitanes; flexy is an understatement!
Dual mixte tubes ran from headtube to rear BB; and from capt's seatcluster to rear dropouts. Our Assenmacher did have an ovalized boom tube. The frame was not at all flexy for us; but then again we are a sub 250-lb team.

Having ridden a mixte for 25 years, I can agree that it is VERY flexible. Still, the real problem with ours (82 Motobecane) is that it is very short in the stoker cabin and it weighs a ton. While we appreciate the stability of our 2 year old CoMotion and it's sveltness, we did some pretty fast rides on the Moto and might not see those speeds again. I still would go for a modern stiffer tandem though.

Frank