Shifter upgrades to a single speed tandem?
 

I picked up a tandem for pretty cheap recently (traded for a lawnmower that itself I bought for only $20). It's in the condition where, although rusty, it will be a nice cruiser just with the usual rebuilds and rubber changes. Schwinn Twinn, c. 1978.

The problem is it's a single speed and aside from riding along the river here in Pittsburgh, that's no good. What are some shifter upgrades I could throw on that's strong enough for a tandem?

It's a 120mm rear hub but a steel frame; considering that and that they made these with shifters too, my LBS figures we might be able to tweak it into accepting a 135. Thoughts on this? Even if we could do that, what hubs are available that aren't Rohloffs costing a grand?

Another solution is to do a front wheel Ebike conversion, but IDK if tough enough wheels have hit the market yet. Anyone know of anyone trying this?

All comments are appreciated 🙂

I would not bother to do major retrofits. Maybe a 3 speed conversion if you can find the parts cheap. The frame will be heavy and probably too flexy to ride in the hills. The front fork maybe too flexy for a motor. Enjoy riding it on the flats though, :) IMHO of course.

You may be able to fit a five speed freewheel hub and a claw type derailleur. Shifting will likely be friction only. Don't spend too much time and money on it - just enjoy it for what it is.

I'm not sure it would be worth spending $1000+ to convert to E on this tandem, but we have been very pleased with the Cytronex C1. 250W max, so no special forks required and very easy to fit and remove.. www.cytronex.co.uk.

If you can actually smash a 135mm hub into the frame, you could probably add an Alfine internal 8-speed hub--which isn't too expensive. Universal Cycles -- Shimano SG-S7001-8 Alfine 8 Speed Rear Hub [ISGS70018BL, ISGS70018AL, ISGS70018BS, ISGS70018AS]

With a new rim, spokes, and nipples you could probably get this done for not too much money.

I had that idea; of course my concern is whether that would be durable enough to hold 300lb on that wheel alone.

Actually I was mistaken in my original post; these came as 1, 5, or 10 speeds; no internal geared hub option.

Currently a 40 spoke wheel; no idea the spoke gauge but obviously pretty thick. I can check later.

Shimano says that they are e-bike certified, so I expect that they can take more power than the old frame! SHIMANO ALFINE Internal Geared Hub Disc Brake 8-speed | SHIMANO BIKE-US

Unless you want to keep the old rim for "style" points, I think that a new rim is the way to go.

It's looking like it; there's not really 40-spoke hubs except for old SA's. Speaking of which...

Sheldon Brown suggests that an old English 3 speed wheel can potentially be used to upgrade a tandem, though I would be concerned with wheel strength. My less-favorite LBS warned about even riding my single English 3-speed over concern about the strength of the zinc 15ga spokes, when I bought a truing tool from them.

"Wheel Upgrades", here: https://www.sheldonbrown.com/opctandem.html

I was browsing SA's website and I found this hub for "heavy duty" use: https://www.sturmey-archer.com/en/pr.../detail/rx-rc5
$115

Seems that that one (and its variants) are the only ones SA sells that are so labeled, aside from a certain single speed coaster.

You can probably get a 126mm vintage (steel) rear dropout to open to 130mm for a modern Road hub, but a 120mm, even a 126, will NOT be opening to 135mm MTB spec. There is no path forward for that Schwinn unless the rear OLD is actually 126mm (5/6 speed). This is unlikely. I can well believe that separate frames were built for the multi-speed models, with the proper rear dropout spacing. For what a motor kit would cost, a very nice mid-1990's tandem could be purchased. This bike didn't cost a lot. Don't invest more in it than its worth.

Yeah that's kind of what I'm thinking at this point. I saw this tandem on FB today for only $150.
https://www.facebook.com/marketplace...5571811401069/

Only concern is that it looks less rigid than my current one.