Which FD for a custom 44 38 26 crankset?

andUK
andUK Posts: 85
edited November 2015 in MTB workshop & tech
As an experimental setup, I've made up a triple chainring of 44 38 26.

I've actually got it to work ok using a Shimano 105 5703 FD. The shifting is fine and the chain, happily, does not jam between the FD and the chainring (I've tried to jam it).

The only drawback is that the outer ring of the FD sits 15mm above the 44t chainring, (which just looks wrong), in order that the wide inner plate clears the middle 38t chainring.

Any useful suggestions on what mtb FD might be better, given that its set up on a road bike frame and there is only 15mm between the down tube and the tyre at the point where the FD clamp goes ( eg. my Shimano Deore FD T610 won't fit between the frame and the tyre).

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Comments

  • A triple mtb should work fine if all the angles and placement is fine.

    The cage should sit about 2mm above the outer ring.
  • andUK
    andUK Posts: 85
    A triple mtb should work fine if all the angles and placement is fine.

    The cage should sit about 2mm above the outer ring.

    With the 44 -38 rings so close in size, the problem is the inner plate hitting on the 38 ring, which dictates how far the outer plate can actually sit above the outer ring.

    Therefore the question should be: what mtb FD triple has a narrow inner plate that would best cope with a 6 tooth difference?
  • The Rookie
    The Rookie Posts: 27,812
    Better to just fit a sensible spread of chainrings really
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • andUK
    andUK Posts: 85
    Better to just fit a sensible spread of chainrings really
    A sensible spread of chainrings does indeed make sense, I've used a 48 38 26 and its fine.

    But as I like to tinker with my bike and based on what gears I actually use, I thought I'd swap the 48 for a 44 and see how that was. As mentioned, it works fine and I like the gear ratios, I use the 44 a lot more than I did the 48. Although it works, aesthetically the FD sat 15mm above the outer ring is not pleasing.

    I'm not so sure that anyone else is such a tinkerer as to have experimented with an unsensible spread of chainrings, but in case they have, did it work and if so, with what components?

    If not, then a basic question would be: what is the smallest tooth difference between chainrings that can work both mechanically and aesthetically?
  • supersonic
    supersonic Posts: 82,708
    Most mechs have a minimum value stated for the difference between the middle and top cog - this minimum is usually 10t, sometimes 8, but may be as much as 12 depending on the design.

    Aesthetics, well, personal preference ;-). All you can do is experiment, and drop it incrementally. But eventually the cage will catch the middle ring. Maybe look for one with the smallest listed difference. (Top-middle minimum capacity).
  • andUK
    andUK Posts: 85
    Most mechs have a minimum value stated for the difference between the middle and top cog - this minimum is usually 10t, sometimes 8, but may be as much as 12 depending on the design.

    Aesthetics, well, personal preference ;-). All you can do is experiment, and drop it incrementally. But eventually the cage will catch the middle ring. Maybe look for one with the smallest listed difference. (Top-middle minimum capacity).

    Thank you! Your info is greatly appreciated!
  • andUK
    andUK Posts: 85
    Most mechs have a minimum value stated for the difference between the middle and top cog - this minimum is usually 10t, sometimes 8, but may be as much as 12 depending on the design.

    Aesthetics, well, personal preference ;-). All you can do is experiment, and drop it incrementally. But eventually the cage will catch the middle ring. Maybe look for one with the smallest listed difference. (Top-middle minimum capacity).

    Thank you! Your info is greatly appreciated!

    And voila! A google search relating to the above has led me to this link:

    http://epicureancyclist.com/review-sugino-ox601d-compact-plus-aka-the-impossible-crankset-44-26/

    which solves my conundrum in a way that I did not envisage!