Triple Chainset to Double

cabbage1879
cabbage1879 Posts: 113
edited May 2011 in Workshop
Basically i have a Cannondale CAAD something that had a triple chainset 50/42/32 and i recently replaced it was a 118mm BB and an old Dura ace 52/39 chainset. Thing is though, it all works great on the stand but when i ride it outside then the change up to the big ring is rubbish, in fact most times it's none exsistent.

I had replaced the original external BB with a 110mm sealed unit 1st, that didn't suit the Chainset as it hit the frame, then i tried a 121.5 and that was to long and took the chainset to far out, so i settled with a 118, but still have issues.


Any thoughts on this would be great, as it's doing my box in. :?

Comments

  • Cleat Eastwood
    Cleat Eastwood Posts: 7,508
    I went from a triple to a double. Have you kept the old triple front mech or did you upgrade that too.

    From what I recall, I had to change the BB to one suited for a double, and I left the triple front mech on and just used the limiting screws to set the mech to an effective double.
    The dissenter is every human being at those moments of his life when he resigns
    momentarily from the herd and thinks for himself.
  • Liam Whyte
    Liam Whyte Posts: 17
    I went from a triple to a double no bother, but make sure the BB you have is the right one. Even a few mms can make a difference... :P

    Maybe a 115 instead of the 118?
  • baldspot
    baldspot Posts: 38
    I also went from a triple to a double and to do so, I changed to the following:

    Chainset, with matching (manufacturer specified) BB
    Chain
    Rear cassette
    Short Cage rear mech

    Is the BB your using the recommended by the chainset manufacturer?
  • cabbage1879
    cabbage1879 Posts: 113
    BB is a square tapered Shimano sealed unit, the Chainset is an older Shimano Dura ace. The front mech is the original triple that the bike had.

    Having looked at the outer ring on the chainset i've notice that there are no pick up notches on it, so i was thinking of putting a different outer ring with those pick up teeth on it and maybe that would help??
  • baldspot
    baldspot Posts: 38
    Would putting a different chain ring on reduce the gap between the chainset and the frame?
  • cabbage1879
    cabbage1879 Posts: 113
    Going to go ahead with a different outer ring with the pick up teeth and see how that goes, if it doesn't work then a 115mm BB may be the order of the day.
  • jimwin
    jimwin Posts: 208
    baldspot wrote:
    I also went from a triple to a double and to do so, I changed to the following:

    Chainset, with matching (manufacturer specified) BB
    Chain
    Rear cassette
    Short Cage rear mech

    Is the BB your using the recommended by the chainset manufacturer?

    But did you change the front mech. There's a big difference between and double and triple front mech.

    - JimW
  • cabbage1879
    cabbage1879 Posts: 113
    Yep, i know there is a difference. But the problem was more to do with the pick up on the outer ring, or it seemed that way. Anyway changing the outer ring seem to do the trick.

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