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Will those 2 work together?

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Will those 2 work together?

Old 05-30-17, 03:36 AM
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Will those 2 work together?


I'm using Shimano ST-RS505 + BR-RS785 Hydraulic Disc-Brake ergos on my bike and I need a front derailleur with big teeth capacity, because I'm using O.Symetric chainrings and the chain rubs the cage either on the upper limit (if derailleur set lower, for the small chainring to work) or the lower limit (if derailleur set higher, for the big chainring to work). I found this one:

Shimano Ultegra FD-6703 Front Derailleur 3x10

Will these 2 work together? My system is o.symetric 50x34. If not, are there other solutions for this problem?

Thank you.
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Old 05-30-17, 04:31 AM
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No it's not compatible. The ST-RS505 are meant to be used with the long arm 4700,5800,6800,9000 Front derailleurs. If you try to use a 6703 FD, the leverage of the FD arm will be totally wrong and it could put extra stress on the internal ratchet mechanism inside the shifter and cause it to fail early. Not only that, the cable actuation will be off too. The swing of the 6703 FD is designed for a different cable pull.

Last edited by trailflow1; 05-30-17 at 05:02 AM.
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