Shifter upgrades to a single speed tandem?
06-24-23, 10:38 AM
#1
Gearhead
Thread Starter
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 🙂
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 🙂
06-25-23, 08:51 AM
#2
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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.
IMHO of course.
06-25-23, 10:45 AM
#3
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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.
06-25-23, 01:13 PM
#4
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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 🙂
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 🙂
06-25-23, 01:25 PM
#5
Junior Member
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.
With a new rim, spokes, and nipples you could probably get this done for not too much money.
06-25-23, 03:39 PM
#6
Gearhead
Thread Starter
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.
With a new rim, spokes, and nipples you could probably get this done for not too much money.
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.
Last edited by hph; 06-25-23 at 03:43 PM.
06-25-23, 03:49 PM
#7
Junior Member
Unless you want to keep the old rim for "style" points, I think that a new rim is the way to go.
06-25-23, 05:09 PM
#8
Gearhead
Thread Starter
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
06-25-23, 05:17 PM
#9
Gearhead
Thread Starter
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.
$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.
06-26-23, 12:03 AM
#10
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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.
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06-26-23, 05:14 AM
#11
Gearhead
Thread Starter
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.
https://www.facebook.com/marketplace...5571811401069/
Only concern is that it looks less rigid than my current one.
