Why does the chain on Shimano 105 front derailleur with Dura-Ace downtube front shifter touch the derailleur cage with the Sugino large chain ring?

The outer limit screw does not move it far enough. I have set the outer limit screw on furthest out I can set it. I don't see any other adjustments anywhere on the Dura-Ace downtube shifter nor on the derailleur.

There is plenty of play on the smaller chain ring, but I don't know how I could move the whole front derailleur further out? Any ideas?

It seems like the Shimano front derailleur/shifter has sort of 2 speed indexing, maybe this is the problem with Sugino front chainring spacing, I'd love to unset this indexing, but I don't know how.

  • Mixing groupset levels is normally okay, but mixing campagnolo with shimano is always a mixed bag. Is your front mech a band-on mount or a braze-on mount? I have shimmed a band-on mount once to get a little more reach to the big ring/
    – Criggie
    Apr 19, 2020 at 6:26
  • Quite possibly the Campy crank has a wider chainline than the eqivalent 105 groupset crank has, The 105 derailleur is designed for the narrower chainline. Apr 19, 2020 at 11:24
  • Its a band-on mount. Chain line explanation seems possible, I guess there is not much that can be done adjustment wide then?
    – Ville M
    Apr 19, 2020 at 18:31
  • Can you flip the chainring to move the chainline to the left? Also, is the crank spider a Campy part or a Shimano part or something else? Could also be a triple bottom bracket, when you're running a double chainring.
    – Criggie
    Apr 19, 2020 at 22:33
  • Flipping didn't help, just tried it, its very symmetrical. But while doing it, double checked the worn out markings, its in fact sugino crank and chainrings, old front derailleur and shifter were campy, and after they broke I replaced them with shimano dura-ace downtube lever and 105 front derailleur. Still mystified by this deficient range on the outside, its only missing 1-2mm.
    – Ville M
    Apr 25, 2020 at 0:22

1 Answer 1


Solved it, it was the nut oriented incorrectly on the dura-ace downtube shifter. Turning the inside nut so that its oriented correctly against the main tube, inside from the lever, and retightening the cable to remove all slack, and then setting limit screws again, I now have the shimano 105 derailleur with the Sugino working correctly (non-indexed). Thanks for all your ideas.

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