I have a Ultegra CS6700 9 speed rear deraileur that came on my bike. Originally the gearing was 12-25, which I changed to 12-27. I was wanting to know of that deraileur would work without a problem switching to a HG50 cassette. The reason for doing so is because it offers a 9 speed 11-32 gearing. I was wanting to get the bigger granny gear so I could more easily go up big hills. Would this new cassette work with just swapping the cassette and adjusting the deraileur to accomodate the bigger gear (also changing the chain to have more length) with the older Ultegra deraileur or would it not shift because of the differences?
1 Answer
The published max large cog for both RD-6700-SS and RD-6700-GS is 30. They can sometimes work acceptably with 32, but they're not designed to and it's hit or miss. The variance is because dropout design is not universal. Putting in a longer b-tension screw or running it in reverse can help. You can also get something like a Wolftooth Roadlink.
Total capacity is 34t for SS and 40t for GS.
answered Apr 17, 2017 at 17:21
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Cheaper than Roadlink is for 9 speed, you can go with a mountain derailleur.– BatmanApr 17, 2017 at 17:57
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@Batman : Only if the cable pull is identical on mountain and road derailleur.– CarelApr 18, 2017 at 13:23
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Maybe it might be helped by the fact that I switched the front from 53/39 to 50/34 or is the limitation solely in the rear deraileur?– AdamFApr 18, 2017 at 18:43
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That has to do with total capacity, and that change will only push against the capacity number, not help, as you're going from 14t difference to 16. It doesn't affect large cog clearance. Apr 18, 2017 at 19:25