Clamp on FD for 47.5 chainline Road 2x11
10-29-21, 05:03 PM
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Clamp on FD for 47.5 chainline Road 2x11
Alright so here's the deal. Soma Fog Cutter build, 2x11 IRD square taper crank 30-46 on a 118mm spindle.
Per Soma the frameset has a 47.5mm chainline with a compact double.
Per IRD, that crank plus 118mm spindle yields a 45mm chainline
I'm running a 105 FD (FD R7000 clamp-on) which if I'm understanding Shimano, is 43.5mm chainline.
So that's not to spec, but it's fine except small chainring and smallest two cogs, which is a cross-chain scenario anyway.
If I want to improve this, it seems like I need to get a longer spindle (which I happen to have), then a FD because the 105 FD won't adjust out to the 47.5mm chainline (I tried).
Suggestions on a FD solution?
Per Soma the frameset has a 47.5mm chainline with a compact double.
Per IRD, that crank plus 118mm spindle yields a 45mm chainline
I'm running a 105 FD (FD R7000 clamp-on) which if I'm understanding Shimano, is 43.5mm chainline.
So that's not to spec, but it's fine except small chainring and smallest two cogs, which is a cross-chain scenario anyway.
If I want to improve this, it seems like I need to get a longer spindle (which I happen to have), then a FD because the 105 FD won't adjust out to the 47.5mm chainline (I tried).
Suggestions on a FD solution?
10-30-21, 05:36 AM
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SRAM makes a "wide spacing" braze on clamp that moves the front derailluer out 2.5mm. It is a bit pricey for a braze on clamp, but it does what you need. I have used them a few times to adapt road front derailleurs to work with MTB cranksets on gravel bikes.
This is just one listing. If you Google "SRAM wide spacing braze on" you will find many others.
https://www.universalcycles.com/shop...s.php?id=68097
This is just one listing. If you Google "SRAM wide spacing braze on" you will find many others.
https://www.universalcycles.com/shop...s.php?id=68097
10-30-21, 06:04 AM
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If you have a 34.9 clamp and a 28.6 seat tube, you can try an offset shim. Or GRX
