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Triple to compact. Advice needed.

jockyfoostjockyfoost Posts: 63
edited December 2009 in Workshop
I've just stripped out my old 105 triple chainset, replaced the rear mech to a short cage (6700) and replaced my front mech for a double (6700 also).
My question is because i'm still using my triple levers do i use the outer half of my left hand shifter ie. the second and third click or the inner 2 clicks when attaching the cable to the front mech?
Also i've fitted this:-http://www.wiggle.co.uk/p/cycle/7/FSA_Omega_MegaExo_Compact_Chainset/5360022887/#moreShould there be a spacer at the bottom bracket or just as is. I ask because i'm getting the chain rubbing on the outer chainring when in the 2 smallest rings of the cassette while in the 34. :?

Posts

  • sovedasoveda Posts: 306
    edited December 2009
    I've got a Defy with Tiagra, the shifter is a "triple" and is set to use the two "inner" index settings. Would probably be the same for your 105 shifters used in the same way.
  • John C.John C. Posts: 2,113
    As long as you set the stops on the mech it shouldn't make any difference which you use. You will not have the same trim facility as you would with a dedicated double lever but I've always believed if you are using big front and biggest back or small front smallest rear you are ill treating the gears anyway.
    http://www.ripon-loiterers.org.uk/

    Fail to prepare, prepare to fail
    Hills are just a matter of pace
  • Thanks for your advice. I've got front mech working now but i'm still wondering about the chain rubbing on outer chainring. This is happening on the 2nd and less so on the third smallest cogs at the back. Surely this shouldn't be so? I'd expect it on the 34-12. I'm now confused as to if i need a spacer in the bottom bracket. I read this:-
    http://www.parktool.com/repair/readhowt ... 95#shimano
  • John C.John C. Posts: 2,113
    try winding the adjuster out a bit, this will lengthen the outer cable pulling the mech further out, you may need to alter the stop screw if the mech is tight against it. I am asuming everything is OK on the inner ring with the largest cogs.
    http://www.ripon-loiterers.org.uk/

    Fail to prepare, prepare to fail
    Hills are just a matter of pace
  • The chain isn't rubbing on the front mech but on the outer chainring.
  • John C.John C. Posts: 2,113
    Just looked at your new chain set and although I have no experience with them, check the crank arm to chain stay measurement on both sides of the bike, this will tell you if the chain set is central or not, are you running 9 or 10 speed , does a compact chain set require a 10 speed chain ?
    http://www.ripon-loiterers.org.uk/

    Fail to prepare, prepare to fail
    Hills are just a matter of pace
  • John.TJohn.T Posts: 3,698
    I had a similar problem when I fit a FSA Gossamer to my Ribble. I solved it by fitting one (or two, I can't remember) spacers behind the drive side bearing cup. I used the ones that fit behind a fixed sprocket for chain line adjustment. They are about 2mm thick. They have been there for 2 years now and have worked fine. I can use all gears but have slight rub on the 34/12 (which I avoid using).
    Re the STI setup. Use the inner ring settings but make sure the mech is not hard up on the top limit screw when on the big ring. If it is then either slacken the screw or the cable a touch. The mech should just move a fraction if you push the lever.
  • rakerake Posts: 3,204
    i know most shimano compacts are 9 & 10 speed compatible and i run one with an 8 speed chain no problems.
  • Thanks John T problem solved with spacers. :)
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