What Chain length?

Anonymous
Anonymous Posts: 79,667
edited May 2008 in Workshop
Hi there,

Just going to fit another Shimano Dura-ace 7801 chain to my Bike...my bikes kitted with Dura-ace 10speed Triple 53/39/30 front and 12-27 rear cassette....I'm sure I remember reading somewhere that you set the length of the chain by having the rear derailler verticle when on Middle front ring(39 ) and highest rear (27)...is this correct?

I'm not using the length of the Chain I'm taking off as i've had nowt but shifting probs and dont trust the length which was fitted at the shop!

Feedback welcome

Comments

  • gkerr4
    gkerr4 Posts: 3,408
    the shimano method is best explained from their own technical documents which can be found here:
    http://techdocs.shimano.com/techdocs/index.jsp

    i always used the method of - chain in biggest chainring and biggest rear cog = rear mech at 45degrees.
  • duckfoot1606
    duckfoot1606 Posts: 89
    1. Run the new chain around the largest front and rear cogs
    2. Adjust length so when you hold the ends together the rear derailleur is pointing forward at +/- 45 degrees from vertical
    3. Join the ends.

    Regards

    A
  • duckfoot1606
    duckfoot1606 Posts: 89
    Gkerr, you beat me to the draw!!
  • System_1
    System_1 Posts: 513
    I never get the rear derailleur involved when measuring chain length, it just confuses matters. The way I've always done it is to run the chain round the largest rear sprocket and largest front ring without going through the rear mech. Then, find the closest point at which the chain could be joined, then add one full link and split/join at this point. This gives the best chain length in most circumstances.

    As always there are better instructions for this method on Sheldon's site including a video.

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