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  1. #1
    Q23
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    chain irregularities?

    So I was working on my bike and noticed how tight it was on part of the stroke. It when from 1/2 of play to, very tight. Spinning the cranks by hand, I noticed the tighting and loosening throught the stoke. It didn't feel smooth at all. So I studied how the chain (low end sliver Izumi) was sitting on the chain ring (a really nice 42t TA) and saw it sat lower in the teeth at a certain point on the ring (where it was loose in the stroke).

    I visually marked where that piont was on the ring and removed then rotated the chain so it engaged at a different spot than before. The loose/ tight part move with the chain. With some work I got it to feel much smoother.

    I would take this to mean my chain is slightly irregular. I would challenge ya'll to experiment doing the same and see if cheap chain are more prone to this. I'll be looking at a new chain soon to see a difference as well. I need a half link right now so the Shadow Conspiracy would be nice for the symmetrical look, but a NJS might be a better choice for quality.

  2. #2
    jack of one or two trades Aeroplane's Avatar
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    How long have you had the chain? The irregularities in it may just be uneven wear. I would also try to center your chainring, using SB's method, to see if you can get uniform tension.
    Quote Originally Posted by Dr Irwin Goldstein
    Men should never ride bicycles. Riding should be banned and outlawed. It is
    the most irrational form of exercise I could ever bring to discussion.

  3. #3
    loves living in the city. Ira in Chi's Avatar
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    What this means is that your chainring is not round, or it is mounted off-center. You can loosen the chainring bolts slightly and tap on the chain to center it. If you have a cheaper chainring it is probably slightly oval, which should not make a big difference while riding but will definitly be noticable to the eye.

  4. #4
    Q23
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    it's a new chain with new ring that has been centered. I tossed the first used ring I hade because it was so uneven.

  5. #5
    biff-o-matic biff's Avatar
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    One thing to keep an eye out for is irregularly drilled cogs. My friend had an EAI one that was threaded slightly off-center. It produced the exact same type of tight/loose pattern that you describe.
    Moyer Cycles: done and done.

  6. #6
    loves living in the city. Ira in Chi's Avatar
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    Quote Originally Posted by biff
    One thing to keep an eye out for is irregularly drilled cogs. My friend had an EAI one that was threaded slightly off-center. It produced the exact same type of tight/loose pattern that you describe.
    I was about to say that. I saw a Soma cog that was threaded the say way.

  7. #7
    Q23
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    again...ring is new and one of the best I've seen and is true and centered. The chain tensioned on one part of the ring. I removed and rotated the chain, and it tensioned on a diffferent part of the ring.
    The cog was a new duraAce. I'll have to check that as well I guess.

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