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  1. #1
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    tandem chainring thickness

    I have Sugino cranks on my 97 Burley tandem, but the chainrings have no identifying marks that I can see, so I don't really know what make they are. I bought a new Shimano granny gear and it's thickness measures 0.083" as opposed to the other cranks 0.125" thickness. Should I just try to find a chainring of the same thickness, or use spacers to take up the slack? And if spacers, which side of the chainring do they go on?
    Thanks

  2. #2
    Gone, but not forgotten Sheldon Brown's Avatar
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    Quote Originally Posted by rlong
    I have Sugino cranks on my 97 Burley tandem, but the chainrings have no identifying marks that I can see, so I don't really know what make they are. I bought a new Shimano granny gear and it's thickness measures 0.083" as opposed to the other cranks 0.125" thickness. Should I just try to find a chainring of the same thickness, or use spacers to take up the slack? And if spacers, which side of the chainring do they go on?
    Try it by itself, should work. My guess is that your original granny ring was aluminum, and the replacement is steel. The steel ones are always thinner, because they don't need to be so thick, due to the greater strength of steel.

    Aluminum granny rings normally have the teeth off-center, pretty much flush with the right (outboard) edge of the chainring. They also usually have counterbores around the mounting bolt holes for the bolt heads to recess into.

    Steel grannies are usually pretty much symmetrical. Try it and see.

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  3. #3
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    Quote Originally Posted by Sheldon Brown
    Try it by itself, should work. My guess is that your original granny ring was aluminum, and the replacement is steel. The steel ones are always thinner, because they don't need to be so thick, due to the greater strength of steel.

    Aluminum granny rings normally have the teeth off-center, pretty much flush with the right (outboard) edge of the chainring. They also usually have counterbores around the mounting bolt holes for the bolt heads to recess into.

    Steel grannies are usually pretty much symmetrical. Try it and see.

    Sheldon "Steel Lasts Longer" Brown
    Code:
    +------------------------------------------+
    |   To do nothing is also a good remedy.   |
    |                          --Hippocrates   |
    +------------------------------------------+
    Wow! Advice from Sheldon himself. I am impressed and I thank you. Yes, I was concerned about the counter sink on the old granny, something the new one does not have. BTW I just purchased a very difficult to find, cold forged, adjustable, Kalloy quill stem from you for the same tandem,and I can't wait for it to arrive. I need to get those bars up higher. Thanks Sheldon

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