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  1. #1
    Junior Member Seamod's Avatar
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    please help my puch

    can anybody help me find out if i can put a new crank set on my 12 speed puch olympian without changing the chain or cassette or other elements?

    any help appreciated

  2. #2
    Senior Member Chombi's Avatar
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    What brand model crank are you trying to put on the bike. We assume that you will aslo be re-using the original bottom bracket (crankset spindle/axle). So you cannot just go buy a new crank out there and expect it to work as you will most likely need a tapered squre holed crankset, similar to the original that came with the bike and not the newer crank mount designs that have come up since your bike was made (I suspect your Puch is from the 80's from the number of speed it has).
    Please post good clear pictures of you bike's present drivetrain and we can the suggest to you what to buy and install on your bike.
    As for using the existing chain and other parts of the drivetrain, as long as the waer on the is not too bad, they will work, but the ideal always i to match a new crank with a new chain, becuase a worn, stretched out chain will accelerate the wear on you new crank's chainring and maybe affect the front derailleur shifting performance on you bike. The same goes for the rear cogs and derailleur if you are changing them out to new too.

    Chombi

  3. #3
    Junior Member Seamod's Avatar
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    i haven't done anything more than browse at cranks. the threads for the pedal are gone in the right crank so it needs replacing. but i would like to replace as little as possible. the following are some photos of the crank and drivetrain. if more is needed please don't hesitate to ask. i really appreciate this help. thank you very much.

    http://www.flickr.com/photos/14922644@N04/6775330231/
    http://www.flickr.com/photos/1492264...n/photostream/
    http://www.flickr.com/photos/1492264...n/photostream/
    http://www.flickr.com/photos/1492264...n/photostream/

  4. #4
    DRF aka Thrifty Bill wrk101's Avatar
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    Can't tell how worn parts are without seeing in person. A chain for that bike here would cost me less than $5, and a rear freewheel (its not a cassette), would cost me $9. Parts look pretty tired to me, so I would spend the $14 if I was installing a new crank.

    You will also likely need a new bottom bracket.

    Now if you have an old crankset laying around, just go ahead and try it.

    Around here, the two cheapest routes are either a donor bike, or a bicycle co-op.

  5. #5
    Junior Member Seamod's Avatar
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    @wrk101z what is the difference between a freewheel and cassette? I'm really living up to my 'newbie' status

  6. #6
    Senior Member Grim's Avatar
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    Chain is the least of your problems. As long as you run a 7-8 speed chain and your gears out back are not worn you should be OK there.

    Thats a pretty narrow looking bottom bracket on the non drive side Unless the angle of the picture is miss leading. There is no way to do a newer triple on that without a wider Bottom bracket if that's what you are going for. Even some doubles are going to give you a problem.

    Some older cranks ran A symmetric Bottom brackets. Before you mount up new cranks you need to mark the center of the BB shell of the frame and measure out both sides and make sure the BB is symmetrical.

    Honestly you might concider replacing both the BB and the cranks together as a set. A modern sealed BB is not that expensive. I have picked up UN 54's that is pretty common to many cranks for $15US on sale.
    Last edited by Grim; 01-28-12 at 09:33 AM.
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  7. #7
    Senior Member Grim's Avatar
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    Quote Originally Posted by Seamod View Post
    @wrk101z what is the difference between a freewheel and cassette? I'm really living up to my 'newbie' status
    Sheldon Brown (RIP) has a great site for a crash course in these things. It will have you a graduate in "bike speak" in no time.

    Freewheel vs Cassette:
    http://sheldonbrown.com/free-k7.html
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  8. #8
    Junior Member Seamod's Avatar
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    I really appreciate all this help. I have to look up 90% of the terms though. I was certainly looking to stay with a double though @grim

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