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new chain cut too long , why?

ukracerukracer Posts: 421
edited November 2009 in Workshop
Just fitting new chain to standard double /12/27 ( if it makes a difference)
Looked at the parktools website for help ,following the large ring to large ring and then 2 link before rejoining.

When on smaller rings tho its way too long.
Have i done something wrong?
Its not a problem as can still go shorter but did not want to make another mistake and go too short.
Any ideas?

Posts

  • Slow DowncpSlow Downcp Posts: 3,041
    You did do large ring/large ring without going through the rear mech didn't you?
    Carlsberg don't make cycle clothing, but if they did it would probably still not be as good as Assos
  • skyd0gskyd0g Posts: 2,539
    Can you check the number of links from your old chain?
    Cycling weakly
  • ukracerukracer Posts: 421
    yes did it without going through rear mech and cannot use old chain as its a new build.
    The only thing i can think of is that i also used a quick link but surely 1 link too many wouldnt make that much difference would it?
  • skyd0gskyd0g Posts: 2,539
    I think you may have just answered your own question. :wink:
    Cycling weakly
  • I always do small-small, means I can fit the longest chain for that specific setup - also gives me a bit leeway when changing cassette/chainset
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  • John.TJohn.T Posts: 3,698
    ukracer wrote:
    yes did it without going through rear mech and cannot use old chain as its a new build.
    The only thing i can think of is that i also used a quick link but surely 1 link too many wouldnt make that much difference would it?
    You did include the quick link in the calculation didn't you.
  • ukracerukracer Posts: 421
    ive now had another go at refitting but seems like im between links ,if that makes sense.
    There is too much slack on small /small combo and rear mech pulled forward on big / big combo.
    Do i have a wrong type rear mech?
    Im not sure the difference so how can i check?
  • balthazarbalthazar Posts: 1,567
    ukracer wrote:
    ive now had another go at refitting but seems like im between links ,if that makes sense.
    There is too much slack on small /small combo and rear mech pulled forward on big / big combo.
    Do i have a wrong type rear mech?
    Im not sure the difference so how can i check?
    The chain is the ideal length when it satisfies two tests:

    1. It is as short as possible
    2. It runs without binding on the big/big combination

    That's it. There's nothing better you can do. There are different methods of establishing that length, but they all have the same intention. Small/small is expected to result in a slack (ish) chain, especially with a wide range of sprockets; the combination is never used anyway – the same ratio will be replicated by some larger sprocket / big chainring combination.
  • ukracerukracer Posts: 421
    balthazar wrote:
    ukracer wrote:
    ive now had another go at refitting but seems like im between links ,if that makes sense.
    There is too much slack on small /small combo and rear mech pulled forward on big / big combo.
    Do i have a wrong type rear mech?
    Im not sure the difference so how can i check?
    The chain is the ideal length when it satisfies two tests:

    1. It is as short as possible
    2. It runs without binding on the big/big combination

    That's it. There's nothing better you can do. There are different methods of establishing that length, but they all have the same intention. Small/small is expected to result in a slack (ish) chain, especially with a wide range of sprockets; the combination is never used anyway – the same ratio will be replicated by some larger sprocket / big chainring combination.


    Thanks for replying Gents , i think something else is not quite right so ive just took it into the LBS
  • John.TJohn.T Posts: 3,698
    1. It is as short as possible
    I would tend to disagree with that. It should be as long as possible while still tensioning the chain in all combinations. If you are running 50/34 and 12/27 this is necessary. As long as the chain does not rub on the small tab on the mech cage it is OK.
  • [quote="balthazar"The chain is the ideal length when it satisfies two tests:

    1. It is as short as possible
    2. It runs without binding on the big/big combination[/quote]



    As short as possible = fail. What if you are running a 12-25 and then fit a 12-27 or 11-28 you'll end up pulling the rear mech into the rear wheel's spokes.

    When you aren't building a WW bike, why not fit the longest chain?
    spamspam.jpg
  • canamdadcanamdad Posts: 188
    This site hasn't failed me yet in getting correct chain length: www.machinehead-software.co.uk/bike/cha ... htmllength:
  • balthazarbalthazar Posts: 1,567
    As short as possible = fail. What if you are running a 12-25 and then fit a 12-27 or 11-28 you'll end up pulling the rear mech into the rear wheel's spokes.

    When you aren't building a WW bike, why not fit the longest chain?
    Ok, I'll qualify:

    The chain is the ideal length when it satisfies two tests:

    1. It is as short as possible
    2. It runs without binding when engaged with the biggest chainring and biggest sprocket you intend ever to use. Ever. Ever ever ever.

    Chains that are needlessly long are more inclined to slap the chainstay, cause chainsuck, fall off, and generally be annoying.

    Oh and thanks for hitting me with the interwebz term du 2008: "= fail". So hip.
  • redddraggonredddraggon Posts: 10,862
    I always fit the longest chain possible. Makes sense.

    1. Longer chain will mean at least 1% less chain wear
    2. I run a compact, so I'm often in the 50T and bigger sprockets rather than change down to the 34t - the 34t is only for longer/steep climbs.
    I like bikes...

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  • andrew_sandrew_s Posts: 2,511
    If your chain isn't long enough to fit onto big/big, and you try to change into big/big, something is pretty likely to break. It's all very well saying that you won't use the big/big combination, but mistakes happen.
  • ukracerukracer Posts: 421
    picked up the bike from lbs yesterday
    The main problem was that i had stripped the rear mech to clean properly and had not tensioned correctly when putting back together.
    o well another lesson learned
    Thanks for the help guys
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