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  1. #1
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    New old Motobecane tandem

    I bought an old Motobecane Interclub tandem the other day. It seems to be in pretty good condition apart from some scratched paint. I'm interested to find out more about it, though, and figure out what sort of work I can do on it to bring up the quality a bit.

    Step one: dating. How do I figure out when this thing was made? I'm not sure where to find the serial number. The things about this bike that distinguish it from others I've seen online are:

    • All the brakes are Mafac "Racer" center-pull calipers. It has two brakes in back, one of them operated by the stoker, and it doesn't have the drum brake that many other Motobecane tandems seem to have.
    • it has a badge saying it's made of 1020 steel, where other Motobecane tandems seem to be made of 2040 steel.

    Some upgrades I might consider making to this bike: indexed shifting (if possible), lower gearing (currently has a half-step Sugino GT road triple crank with 110mm bolts and a 5-speed rear (freewheel?)), replacement cables and housings, as well as new brake levers -- possibly a double-pull rear lever to return all brake control to the front rider. It seems a little weird to give the stoker partial control of the braking, though I would welcome anyone's thoughts on that.

    One more thing: I might need to get a longer front seatpost but it looks like the seatposts are the wonderfully rare 15/16" (23.81mm). Some online searching turns up no modern micro-adjusting seatposts of that size, only the old-style plain tube variety. Does anyone make a modern seatpost that'll fit this thing?

  2. #2
    Senior Member SJX426's Avatar
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    Pictures would be of great help, maybe, in dating based on the graphics and frame construction. Include drive train on both sides and the rear triangle to get a "picture" of your brake configuration.

    SN may be hit or miss. I have a 1972 Motobecane Le Champion without any SN. I know it is a 72 from the color, configuration of components and the fact I bought it when it was a year old! But there are other features that can help in identification of era. The Mafac's are a good indicaiton of it being in the 1970's range.

    Do a google search on 1020 vs 2040 framed bicycles. There is a wealth of info out there.

    I am new to Tandems so don't know the timeline for construction geometry but ..... there have been changes in the rear spacing of the drop outs. You should measure it for us. it is the distance between the inside of the drop outs with the wheel installed or the distance between the nuts of the wheel (those that mount on the inside of the drop outs). This will help determine the significance of changes you are curios about. You can likely change to index but to how many speeds will be determined by how much if any adjustment is required to the frame drop out distance. If a change is required, new hubs will likely be needed.

    Double pull for the brakes is attainable. Visit Tandem East site or other tandem stores on line for configuration options.

    You have a French bike. Nearly all the dimensions are unique to them, as you have discovered with the post. One option is to find one that is close but over sized, with enough wall thickness, it can be turned down to the right diameter. Otherwise you will need to keep searching.

    Also useful would be to know your crotch bone to floor (bare foot) measurement and then measure from the Captains crank spindle center to the center or top of the top tube at the interseciton of seat tube. My suspicion is the frame may be too small for you. Do the same for your Stoker and let us know.

    Looks like homework, huh!

    .

  3. #3
    Senior Member zonatandem's Avatar
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    Motobecanes all have similar issues as other older French tandems like the Follis, Gitane, Lejeune and Gottfried:
    French threading.
    Upgrades are minimal for that type of older machine
    Mafac brakes are OK; however to put both rear brakes on one lever for pilot control can be an issue. The double pull cables and lever are hard to come by and a PIA to set up.
    Suggest barcon shifters for indexing. Easier to find, relatively inexpensive and very dependable.
    These old tandem can be a bit on the whippy side and would not suggest putting a lot of $$ into it.
    Enjoy the ride as is and save your $$ for a better machine.

  4. #4
    Senior Member SJX426's Avatar
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    For frame material, check this discussion: http://www.bikeforums.net/showthread...020-2040-steel
    This is a low end Tandem, Just ride it and have fun! Don't sink too much money in it, unless you pain next to nothing, it would be a loss.

  5. #5
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    Thanks for the advice. We bought this tandem as a way of testing the waters in terms of tandems. We've rented and enjoyed tandems before, and this one rides as well or better than the ones we rented, so I figured it was worth the $260. If we end up riding it enough then we'll probably sell this one and buy a better quality one some time in the future. So far the only upgrade I've done is to replace the front pedals because I can't stand pedals that require straps. I'll probably stick with just that one change for now and see how it goes. The brakes are the one area that worries me, since they feel pretty weak, but I may be able to do some cleaning/lubricating/adjusting to get them working a bit better.

  6. #6
    Senior Member waynesulak's Avatar
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    I agree with all the above comments about not sinking a lot of money into that machine. There are a few exceptions in my mind:

    1 - good brakes. This is non negotiable.
    2 - replace tires and tubes if needed
    3 - Components that you know can be transferred to a newer bike should you purchase one. Examples saddle and pedals.

    Have fun and remember to save any old parts like pedals so you can take off your upgrades and put them back when you sell it.

  7. #7
    Nigel nfmisso's Avatar
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    You absolutely must have confidence in your brakes. Your stoker has to trust you are in complete control.

    I would suggest changing to Tektro R536 or R559 depending on the "reach". Look up "reach" on Sheldon Brown's website if you need instructions how to measure.

    I swapped Tektros for the very good for their day mid '80's side pulls; difference was incredible. Most of my other bikes have linear pull (aka V-brakes) including our T50 tandem which has Avid SD 5.
    Nigel
    Mechanical Design Engineer

  8. #8
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    If Sheldon Brown is to be believed, the Mafac Racer brake is perfectly good, even compared to modern brakes (see http://sheldonbrown.com/harris/mafac.html). He said the better thing to do would be to replace the cables and housings because modern ones have much better performance. But as I said before, I'm at least going to try it out for one or two rides and see how well I think the brakes work. If they still seem inadequate I'll replace the cables, housings and maybe levers. We'll see where we go from there. As several people have said, it's probably not worth sinking a lot of money into this bike.

  9. #9
    WillFam-Clovis,CA
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    Don't forget to replace the brake pads as an important upgrade! Depending on how old the pads are or how long they have been exposed to the sun, they will get hard (like an old pencil eraser) and greatly affect braking ability. Have fun. I have a French Gitane of that vintage that has been out of service for awhile. My boys and I are spending a lot of time on a triplet. I'll get to putting back in operation eventually. Enjoy while you can.

  10. #10
    Senior Member zonatandem's Avatar
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    Enjoy the ride TWOgether!
    Rudy and Kay/zonatandem

  11. #11
    Senior Member SJX426's Avatar
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    All modern brakes are dual pivot. Centerpulls are dual pivot. buy Koolstop brake pad replacements. It will make a huge difference. Past the pads is upgraded housings and adjustments. The closer the pad is to the braking surface the better. This may drive checking the "true" of the rim, which should be done anyway. Your level of enjoyment will increase with confidence in braking!

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