7/11/17 - My latest addition, with more pics here
I stumbled across this tandem on Craigslist, and noted the seller included the date code from the serial number. It came out to a 1971 Schwinn. From the pics he put up, it was obvious it was a 27", and I went to the online arcives of old Schiwnn catalogs to see if I could figure out what it could be. The only tandem options available in '71 were the 26" Twinn and Deluxe Twinn, both 26" wheels, and the Paramounts. I thought I struck gold, and raced over to the guys house to buy the bike. I didn't really look it over too well, as the price was pretty cheap for a tandem ($100), and I threw it in my van, noticed it was pretty light, and brought it home. For the price, regardless what it ended up being, I knew getting it wasn't a bad decision.
After looking over the bike, I noticed a lot of discrepencies between what I bought and the Paramounts. While it was a 10 speed with 27" wheels, the components were not top shelf stuff, most of it being Varsity / Continental vintage. The faded decal on the side clearly had this bike named a "Schwinn Sports Tandem". So I went back to the web, and the catalogs to see if I could determine what it was that I bought, and what the specs were. I was most interested in determining the frame material, as it feels about half the weight of the '75 Twinn I previously owned. After a few hours on the web, I struck out. I can find no info anywhere on this bike. No pics, nothing on Google, nothing speced the same. The only other tandems I could find from Schwinn that were 27" and not Paramount were the Twinn Sport, which started manufacture in '78, and the late 80's DuoSport. Both of those were speced with 3 piece cranks, and had the connecting chain on the left hand side.
So right now, I'm not sure what I have. It's possible it was a one-off I suppose, or maybe a concept bike for what would eventually become the Twinn Sport. As for now, I'm not sure what to do, fix it and flip it, upgrade it and keep it, or restore it and keep it. The components are as follows:
- 27" Schwinn tubular rims - 105ga rear, 080ga butted front
- Huret cranks (appear to be the same as was used on the '61-'62 Varsity)
- Atom drum brake
- Normandy? front hub
- Maillard 5 speed 14-28 freewheel
- Schwinn approved derailleurs (Rebranded Huret)
- Twin Stick shifters (older style)
- Schwinn deluxe headset
- Schwinn Alloy "S" stem
- Schiwnn middleweight handle bars (stoker bars were MIA)
- Center-pull front brake (I'm making this assumption based on the headset mounted cable hanger, the front brake was MIA)
7/14/17 - Update
I started to disassemble the bike, and so far, it's in pretty bad shape. The chrome is peeling on the rims, the cables were rusted solid in the housings, it's apparent this bike sat outside for a good number of years. I've decided to strip it down, and find a couple of donor bikes (most likely Continentals), clean it up, and see how it rides before I decide what to do with it. I'm trying to see if I can find any other date codes on the bike that will assist in documenting it's possible time of origin and see if it lines up with a timeline that makes sense to it being a factory prototype of what would become the Schwinn Twinn Sport which debuted in 1978. I'm finding a lot of info that seems to suggest that dating a Schiwnn by its serial number is not always accurate, especially with tandems, so it's theoretically possible this bike was actually buile some time after 1971, perhaps closer to 1974-ish.
I stripped the bike down to the frame, hoping to find some date codes on the components, but so far no luck. The front hub is corroded where I can't read the shell, and will need to cut the spokes out and polish the hub before I can see if there is a date code present. Same thing with the fork, unfortunately though, the stem is stuck solid in the fork, and I have it soaking in PB Blaster (same goes for both seat posts). I need to pop the freewheel off the rear hub so I can check that for date codes. So far the only markings I have found are on the cranks. Both are marked as "SA 9 7". Unfortunately I don't know if this corresponds to a date or not. Pics to follow.
7/17/17 - Update
After 4 hours of fighting, the seat posts and stem have been removed. The stem was removed by removing the stembolt and wedge, cutting the stem off flush with the top of the fork, and removing the form from the frame. Once removed I clamped the fork in a vise (padded with some rage, of course), and proceeded to drill out the stem as much as I could with a 3/8" drill and a 1/2" bit. Once that was done, I got to work with a hack saw blade, and carefully cut a notch into the piece of aluminum. The blade feels like it has more drag when you're cutting the aluminum, and starts moving faster when you're on the steel of the steerer. Although I didn't make it all the way through the aluminum in the middle of the stem, I made enough of a slit on the top and bottom that I was able to pound out what remained with a hammer and a steel punch. The seat posts were removed by putting the end of the seat post into my vise, and twisting the frame back and forth, tightening the vise as the end of the seatpost became distorted. Finally I heard the first break loose, and kept twistintg it back and forth, until I was finally able to twist it out. The same happened for the second post. Looking at how rusty the seat posts were, I'm surprised I was able to get them out without a torch.
I was able to sand some paint off the steerer tube, and located a date code of "3J", which I've been told equates to October of '73. After reinspection, the cranks are actually stamped "SA 9 71", marking them as week / month 9 of 1971. So far, so good, it's still looking that the parts I inherited are indeed original, and that this was a one-off / prototype of the Twinn Sport released in 1978. Next to check are the front hub, which is still pretty corroded, and the freewheel, which was rusted so badly it didn't move.
The restoration has begun, and I have cleaned up the frame with rubbing compound, followed by some polishing compound, followed by a coat of wax. The headset has been cleaned up and put back together, but the locknut was stripped. Work on this project will likely slow down now as I continue to search for a mid 70's Continental I can scavenge for parts. Hopefully I can come across something that's missing wheels for cheap so I don't feel guilty about pulling something rideable off the streets just for a few parts.
8/7/17 - Update
Scrounged some replacement rims from Working BIkes, as well as a stem and some pedals. Replaced the headset from one that came off my Superior. Disassembled and rebuilt the hubs, cleaned up all the spokes, and relaced the wheels. Replaced the rear derailleur, and disassembled cleaned up and reassembled the front derailleur. Got the cranks put back together, and forgot to note if there was anything different about the set used on the rear compared to the front. Installed the timing chain and idler gear, and then the bike sat for a while. A couple of other projects came up, and I still wasn't having any luck locating a center pull front brake. I mean they were out there, but $25 parts and shipping for just an old caliper from a Continental was a little steep. I could find whole bikes for under $50 locally, but hated the thought of scrapping an entire bike just for a caliper, so the hunt continued.
After I completed a couple of other side projects, I went back to this one and went to install the rear wheel with one of Tioga Bloodhound tires I had planned on using. i want as fat and as high of a profile tire I can find to help protect the rims from potholes, as you can't really bunnyhop over them like you can on a road bike. I went to put the rear wheel on, and discovered that the stays between the seat and chain stays had next to no room to accomadte a fat tire, and the Bloodhounds were rubbing pretty badly. I threw a set of really old Continental touring tires on there, and they had about 1/4" clearance on either side. I was hoping to use Continental Gatorskins, like I had purchased for my Superior, but there's no way those were going to fit. While my search continued for a front caliper, I was able to get the derailleurs back on, and get the drive chain installed. I also ordered a set of Velo Orange Grand Cru randonneur handlebars for the front (48cm - way wider than the GBs from the Continentals), and a pair of Nitto B206 Nordeast bars for the stoker. Afterwards the bike sat again while the parts hunt continued
A few days ago, I finally got over to the bike shop, and the owner let me root around the junk pile in search of parts. I did manage to get another seat post, as well as some NOS DiaCompe brake levers and extensions. Saturday, I finally struck gold. On the way walking home from dropping car off at the garage, my wife and I walked by a yard sale, and there I found a mid-70's road bike with Dia Compe centerpull brakes. $25, and I finally had what I needed. based on the componentry, I don't think this was a high end bike (cottered Huret cranks mixed with SunTour slant-parallelagram rear derailleur), yet the parts were pretty decent. Anyway, the brake parts went on the tandem, the derailleurs replaced some worn out 70's crap on a Traveler for my kid's girlfriend, the wheels were claimed by my other son for a fixie project, I now have some spare chainrings for the tandem, and now I have yet another 25" frome just in case. Anyway, the last of the project went pretty smooth. Brakes went together, crappy seats for testing went on, I ordered a set of 27 X 1 1/8 Continental Ultra Sport tires that have a very high profile, yet fit between the stays. The bike is now complete, and went out on its maiden voyage. I found that the sterring wants to flop left to right at very slow speeds, but at higher speeds, it was pretty steady. Still need to take it for a couple longer rides to make sure this is a keeper, but if it is, I plan on buying Brooks B67 / B66 saddles and maybe a paint respray down the road.