Chain length

Pekka
Pekka Posts: 119
edited August 2007 in Workshop
I recently ungraded my tourer from a seven to a nine speed cassette. The cassette is 12-34 and the triple chainset is 26 36 48. I think I measured and fitted the Dura Ace chain correctly but have noticed that the chain rubs the front mech cage when it is on the smallest chain ring and the smallest cog as though the chain was too long. I have also experienced poor changing in higher gears, although this may not be related. Both front and rear mechs are XT.

Comments

  • nicklouse
    nicklouse Posts: 50,673
    that is not a combination ofgears that you should be useing.

    if you have a look at the instructions that came with the chain/cassette or the front crankset it will show you what gears you should not be using,
    ,

    eg. small - small or big - big.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • John.T
    John.T Posts: 3,698
    Nicklouse is quite right about not using those gears. The chain is very out of line and will cause increased wear as well as rub. The 9sp cassette is wider than the 7sp so makes the problem worse. This chain rub is nothing to do with chain length and is not affected by it in any way.
    If I remember correctly the way to set chain length on a triple is to run the chain round the large ring and the large cog but not through the mech then to add 2 links to this length. You can check this on the info sheets on the Shimano website.
    My Fleet.

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