Front derailleur woes

RickshawBob
RickshawBob Posts: 2
edited March 2013 in Workshop
Hi guys,

I've recently been replacing parts on an old road tandem I've acquired and currently having massive issues with with reach of the front derailleur.

I have replaced the original cranks and bb, there is not a significantly big gap between the bb and cranks, but the derailleur simply will not reach the top ring. After hours of pondering all i can think of is some way to shim the derailleur out further, or find another one with a particularly long reach.

I initially had the problem by trying to use a modern truative crankset on the old ISO square taper bb. Figured a nice new 113mm bb would bring the cranks much closer to the bike... but the problem still haunts me!

Have tried everything and figured it was time to ask the internet... Smaller BB? Different derailleur? argh!

Any advice appreciated. Can't wait to get this off my workstand :)

Kind regards,

Rob

Comments

  • sungod
    sungod Posts: 16,869
    if you back off the limit screw and manually move the cage out as far as it'll go, is that far enough?

    if it is, but you can't get the same range when actuated by the shifter, maybe the fd has a different pull ratio to the shifter

    otherwise, measure the chainline (see here: http://www.parktool.com/blog/repair-hel ... e-concepts ), for a road double it's around 43- 44mm, triple is bit more, once you know it you can look for a matching fd
    my bike - faster than god's and twice as shiny