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  1. #1
    vjp
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    Tandem Questions

    I recently acquired a 1982 Freschi Supreme tandem and I have only a passing knowledge of Tandems and how they are set up so I am hoping that the group will be able to answer some questions I have.

    Freschi worked as a builder for Pogliaghi before going out on his own and this bike has a lot of similarities to the Pogliaghi tandems which are fairly rare and quite highly regarded. It is kind of in between a racing and touring tandem. It has very clean small bosses on the front fork and seat stays for racks and it has fender eyelets but the wheel/tire clearance is tight and it does not have canti bosses. Maybe it is a "sportif" or credit card touring bike. It could possibly be a good century bike.

    My first question is about the rear spacing. It is 130mm when the road standard in 1982 was 126mm and 6 speed rear gearing. Of course modern road rear spacing is 130mm with 8/9/10/11 rear gears and I believe that modern Tandem spacing is 135mm to 140mm with 9/10 rear gears being the standard. Could I use a modern 36 hole 130mm rear 10 speed hub without issues?

    My second question is about the rear brakes. It has two brake bridges and has brake cable braze-ons on the top tube from the front and also braze-ons along the diagonal cross member in the stokers cockpit only to the second bridge. I believe that this is for a stoker controlled "drag brake". Is this correct? Would it be operated with a regular brake lever or with a modified "retro-friction" shift lever?

    I wasn't looking for a tandem but it is so cool, in beautiful shape and I traded a couple of bikes in my heard for it so my investment is conservative. I have a 14 year old son who is interested in riding it with me which is why I am posting this instead of just flipping it but I am not really interested in chasing down vintage parts for it. If I do build it up it will be a retro-rod, of course without modifying anything on the frame/fork.

    Thanks for any feedback.

    vjp

  2. #2
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    Quote Originally Posted by vjp View Post

    My first question is about the rear spacing. It is 130mm when the road standard in 1982 was 126mm and 6 speed rear gearing. Of course modern road rear spacing is 130mm with 8/9/10/11 rear gears and I believe that modern Tandem spacing is 135mm to 140mm with 9/10 rear gears being the standard. Could I use a modern 36 hole 130mm rear 10 speed hub without issues?

    My second question is about the rear brakes. It has two brake bridges and has brake cable braze-ons on the top tube from the front and also braze-ons along the diagonal cross member in the stokers cockpit only to the second bridge. I believe that this is for a stoker controlled "drag brake". Is this correct? Would it be operated with a regular brake lever or with a modified "retro-friction" shift lever?

    Thanks for any feedback.

    vjp
    Sounds like an interesting specimen. Please share some photos.

    1) Rear-spacing standard for modern tandems is 145 mm. (Santana uses 160 mm.) This wider standard allows the rear wheel to be built "dishless", i.e. symmetric with spokes on both sides at equal tension or nearly so. This makes a stonger rear wheel and alleviates a notorious Achilles heel of tandem bicycles. Your bike at 130 mm was probably intended for a 6- or 7- speed freewheel or cassette hub, with spacers added to the left end of the axle with the same goal: to make the wheel less asymmetric than a standard hub at 126 mm would have been. (Our Santana Targa from 1989 was set up that way.)

    However, there is no reason you can't put a modern 130 mm rear hub in yours as long as your stoker is on the light side. A 40- or 48- spoke wheel would make it more durable but I don't know how much luck you'll have finding 130 mm hubs drilled for that many spokes. You might also find 10-speed chains too fragile for reliable tandem use. I'd suggest sticking to 8-speed cassettes and chains during the working up of an old try-it-see-if-you-like-it tandem.

    You could go with whatever you have and rethink things if you start breaking spokes and chains. It'll fit, no problem, it just might not be durable enough for your needs, especially if your son bulks up a lot during his growth spurt. (But by then he might be too tall for it, or too worried about being "uncool" to want to ride with his Dad anyway.)

    2) In those days, the only third brake option for a tandem was an Arai drum brake mounted on the rear -- the left side of the hub was LH-threaded to allow the brake drum to be screwed onto it. You're correct: it was a "drag" brake intended for the "set-and-forget" mode, much like a parachute. There were many strategies for operating the drum which I won't go into here since it is unlikely you'll be able to find, or need, a drum brake for what you're likely to use this tandem for. It's necessary only for heavy loads (people or luggage) on long steep descents where speed needs to be controlled. You can't stop the bike with one so you need two rim brakes anyway.

    Thanks for posting this here, since the Tandem Forum is mostly people with exotic new equipment who aren't much interested in C&V stuff. However they can help a lot with getting up the learning curve of tandeming itself, no matter what you're riding. Good luck with your project. Please let us know how it turns out.

  3. #3
    vjp
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    Thanks for the very good start!

    The third brake option on this frame is actually another brake bridge between the diagonal cross members. It takes an allen nutted brake the same as the other bridge.

    vjp

  4. #4
    Freewheel Medic pastorbobnlnh's Avatar
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    Tandems can be a whole new mystery and a great deal of fun. Over the winter I converted a Schwinn EF frame drop-bar 10 speed tandem ('79 Twinn Sport), into an upright 18 speed. The upright bars fit my wife's style better.

    Originally it had a front side pull rim caliper and a rear drum, and the breaking was horrible, especially for riding in the mountains and stopping two heavy riders (it also had steel rims). Since I wanted to rebuild the wheels with aluminum rims, I decided to really beef up the braking power, so I found a front drum brake hub, added a rear centerpull caliper, and swapped the front caliper for a sidepull.

    The end result was quad brakes, two rim calipers and two hub drum brakes. So how could I operate four brakes? My stoker could do two, but I don't trust her and I like to be in control. I had thought about thumb ratchet shifters to set the drums as drag bikes, but when I tried one I didn't like the performance. So I ended up with dual cable pull levers. In my case the right lever operates the centerpulls and the left operates the drums.

    I'm really satisfied with this set up, but I realize it is not for everyone. Most of the posters over on the tandem sub-forum thought I was foolish to set my tandem up this way, but it gives my wife a great deal of comfort knowing I can really stop rather quickly.

    Best of luck on your project.

    Levers.



    Cable guides added to handle extra brakes.

    Bob
    Dreaming of Summertime in NH!

    Visit my websites:
    FreeWheelSpa.com orpastorbobnlnh.com

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    New one on me; shows you learn something every day. So the rear wheel passes between three pairs of stays? A pair each of the usual seat stays and chain stays, and another pair of small-diameter tubes that pass from the head tube (or maybe the captain's seat tube) all the way to the rear drop outs passing outside the two seat tubes on the way? And those two extra tubes have a brake bridge between them, similar to the bridge between the seat stays?

    Modern tandem frames use a single bracing tube that passes from the head tube "through" the captain's seat tube and ends in the stoker's bottom bracket shell. The older method allowed a standard single-bike bottom bracket shell for the stoker's position. I hadn't realized there could be a brake bridge mounted there but since you would want something to stiffen those tubes at the last possible point before the tire got in the way, it would make sense. So there would (or could) be two caliper rim brakes acting on the rear wheel, if I'm reading your post correctly.

    Two brakes applied on the rear wheel at the same time would be quite likely to lock up the rear wheel and skid it, especially with a light stoker. Some theories, but I'd like to hear from a veteran of that era to confirm:

    1) If the captain was controlling front and rear brakes off the same lever (an obsolete setup used back then that required special "splitters" or dual-cable levers), he might want independent control of the (other) rear brake if the road surface argued against using any front braking.

    2) The stoker might have been given independent control of one rear brake to allow her to actively oppose the captain's daredeviltry on steep descents. But communication is a better way to resolve these conflicts. Braking that surprises (or pisses off) the captain can be dangerous.

    3) Two rear rim brakes would not reduce the risk of tire blow-off from overheating, since all the heat from the rear is still going into the rim. However, rear brakes on a tandem were often inadequate because the long cable stretches more, and if it is running inside housing, is exposed to more friction. The builder may have wanted therefore to provide two rear brakes to maximize the contribution of the rear wheel to braking effectiveness.

    Today, most of us running rim brakes on a tandem with close clearances like yours use (two) dual-pivot caliper brakes with aero levers which provide easily enough mechanical advantage to generate enough power to stop a tandem. You can mount one rear brake on the usual seat stay bridge and ignore the other bridge. Do not attempt to mount "long-reach" calipers, particularly on the front, because you need every every inch-ounce of lever force at the rim for this to work. Also make sure that the Allen nut that attaches the front brake is long enough to engage six threads. Tandems often have thick fork crowns and the usual stock brake nut may not be long enough for a good safe engagement. (You can get extra-long brake nuts from loosescrews.com.)

  6. #6
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    Quote Originally Posted by conspiratemus View Post
    2) The stoker might have been given independent control of one rear brake to allow her to actively oppose the captain's daredeviltry on steep descents. But communication is a better way to resolve these conflicts. Braking that surprises (or pisses off) the captain can be dangerous.
    I'd think letting the stoker have independent control of one of the brakes was the reason for the second brake bridge and cable routing. In that case it would be operated off a regular brake lever on the stoker's bars. As mentioned, this doesn't help with the usual tandem brake problem in mountains - excessive heat buildup in the rims.

    BTW, when our daughter was my stoker (first with a kid-back setup and later with normal cranks) she quickly discovered that the open run of cable along the top tube gave her effective control of the rear brake even without use of a brake lever.

  7. #7
    Velocommuter Commando Sirrus Rider's Avatar
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    Quote Originally Posted by pastorbobnlnh View Post
    Tandems can be a whole new mystery and a great deal of fun. Over the winter I converted a Schwinn EF frame drop-bar 10 speed tandem ('79 Twinn Sport), into an upright 18 speed. The upright bars fit my wife's style better.

    Originally it had a front side pull rim caliper and a rear drum, and the breaking was horrible, especially for riding in the mountains and stopping two heavy riders (it also had steel rims). Since I wanted to rebuild the wheels with aluminum rims, I decided to really beef up the braking power, so I found a front drum brake hub, added a rear centerpull caliper, and swapped the front caliper for a sidepull.

    The end result was quad brakes, two rim calipers and two hub drum brakes. So how could I operate four brakes? My stoker could do two, but I don't trust her and I like to be in control. I had thought about thumb ratchet shifters to set the drums as drag bikes, but when I tried one I didn't like the performance. So I ended up with dual cable pull levers. In my case the right lever operates the centerpulls and the left operates the drums.

    I'm really satisfied with this set up, but I realize it is not for everyone. Most of the posters over on the tandem sub-forum thought I was foolish to set my tandem up this way, but it gives my wife a great deal of comfort knowing I can really stop rather quickly.

    Best of luck on your project.

    Levers.



    Cable guides added to handle extra brakes.

    Sweet looking Twinn!
    Riding 19 Years of Specialized Sirrus Tradition.
    Live in Houston? Come to http://bicyclecommutehouston.blogspot.com/
    1988 Specialized Sirrus, 1989 Alpine Monitor Pass MTB, 2007 Specialized Sirrus 700C hybrid, 2007 Schwinn Town & Country trike, 1970 "Resto-Improved" Raleigh 20, 1970 "WIP" Raleigh 20, and 1980 "WIP" Schwinn Town & Country trike

  8. #8
    Freewheel Medic pastorbobnlnh's Avatar
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    Thanks! Sorry about the poor focus.

    Bob
    Dreaming of Summertime in NH!

    Visit my websites:
    FreeWheelSpa.com orpastorbobnlnh.com

  9. #9
    vjp
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    Quote Originally Posted by conspiratemus View Post
    New one on me; shows you learn something every day. So the rear wheel passes between three pairs of stays? A pair each of the usual seat stays and chain stays, and another pair of small-diameter tubes that pass from the head tube (or maybe the captain's seat tube) all the way to the rear drop outs passing outside the two seat tubes on the way? And those two extra tubes have a brake bridge between them, similar to the bridge between the seat stays?

    Yes, exactly!!

    Modern tandem frames use a single bracing tube that passes from the head tube "through" the captain's seat tube and ends in the stoker's bottom bracket shell. The older method allowed a standard single-bike bottom bracket shell for the stoker's position. I hadn't realized there could be a brake bridge mounted there but since you would want something to stiffen those tubes at the last possible point before the tire got in the way, it would make sense. So there would (or could) be two caliper rim brakes acting on the rear wheel, if I'm reading your post correctly.

    Correct!

    Two brakes applied on the rear wheel at the same time would be quite likely to lock up the rear wheel and skid it, especially with a light stoker. Some theories, but I'd like to hear from a veteran of that era to confirm:

    1) If the captain was controlling front and rear brakes off the same lever (an obsolete setup used back then that required special "splitters" or dual-cable levers), he might want independent control of the (other) rear brake if the road surface argued against using any front braking.

    The cable braze-ons are not set up to allow the use of a splitter set up

    2) The stoker might have been given independent control of one rear brake to allow her to actively oppose the captain's daredeviltry on steep descents. But communication is a better way to resolve these conflicts. Braking that surprises (or pisses off) the captain can be dangerous.

    3) Two rear rim brakes would not reduce the risk of tire blow-off from overheating, since all the heat from the rear is still going into the rim. However, rear brakes on a tandem were often inadequate because the long cable stretches more, and if it is running inside housing, is exposed to more friction. The builder may have wanted therefore to provide two rear brakes to maximize the contribution of the rear wheel to braking effectiveness.

    Today, most of us running rim brakes on a tandem with close clearances like yours use (two) dual-pivot caliper brakes with aero levers which provide easily enough mechanical advantage to generate enough power to stop a tandem. You can mount one rear brake on the usual seat stay bridge and ignore the other bridge. Do not attempt to mount "long-reach" calipers, particularly on the front, because you need every every inch-ounce of lever force at the rim for this to work. Also make sure that the Allen nut that attaches the front brake is long enough to engage six threads. Tandems often have thick fork crowns and the usual stock brake nut may not be long enough for a good safe engagement. (You can get extra-long brake nuts from loosescrews.com.)

    Thanks for the help.

    vjp

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