EDIT – FD is actually an older 105: RD-5800. Does not show ‘total capacity’
CAAD12 105 – Im moving to compact as I climb a lot more
Front chainring: 110x50T and 110x34T (Both FSA)
Rear cassette: 11-32T (Shimano CS-R8000)
Front derailleur: Shimano Ultegra FD-R8000-F
[https://bike.shimano.com/en-EU/product/component/ultegra-r8000/FD-R8000-F.html](https://bike.shimano.com/en-EU/product/component/ultegra-r8000/FD-R8000-F.html)
Rear derailleur: Shimano 105 RD-5800 – [https://bike.shimano.com/en-EU/product/component/105-5800/RD-5800-GS.html](https://bike.shimano.com/en-EU/product/component/105-5800/RD-5800-GS.html)
50-34 = 16
11-32 = 21
16 + 21 = 37 differential
When reading the mid cage 105 rear, I should be able to make the 16 (website says 16) though the link does not show a “total capacity”
I have measured the new chain according to the 2 rivet Park Tool video. I have calibrated H and indexed gears. Everything great except:
Getting into small front and big rear causes the rear derailleur to basically collapse on itself and makes noise.
Getting into small front and small rear will create lots of slack and chain will basically rest on front chainring. If I try to pedal backwards it slacks up. I worked the B screw a bunch, but it doesn’t seem to really help.
I have no issue buying a long cage rear, just want to make sure there isn’t something I am missing.
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EDIT – Photos
EDIT2: My RD doesnt show SS or GS. Is there a way to tell? This link shows total capacity differences between SS and GS:
[https://www.cyclingboutique.in/products/shimano-rear-derailleur-105-rd-5800-11-speed#:\~:text=Total%20Capacity%3A%2033%20teeth](https://www.cyclingboutique.in/products/shimano-rear-derailleur-105-rd-5800-11-speed#:~:text=Total%20Capacity%3A%2033%20teeth)
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https://preview.redd.it/k5bkfhcbtefc1.jpg?width=1512&format=pjpg&auto=webp&s=e34c477e449cc732adf5a18bbdcd941a6e8d488b
https://preview.redd.it/an828hcbtefc1.jpg?width=1512&format=pjpg&auto=webp&s=c28b264d70ca1e8c171ea1dc1ca0dbf7332f8d44
https://preview.redd.it/5645nlcbtefc1.jpg?width=2016&format=pjpg&auto=webp&s=c1f5c20295709bc23f807e5904815167f9cabf31
https://preview.redd.it/g5sn8ocbtefc1.jpg?width=2016&format=pjpg&auto=webp&s=d59fdab5e73628f3fdf921dc2a34c8e4b6870b4d
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by lsxgh
7 Comments
Front and rear deraileurs are the correct ones for your 34/50T + 11-32T. Sounds like the chain is too long. Or possibly not enough B-screw turned in. Basically it’s an installation/tuning problem you’re having, not a equipment compatibility issue.
You need to post a pic of the big-big combo and small-small combo.
FYI: In this context, “big” in back refers to the 32T which is the lowest gear. Small is the 11T.
~~All the components should work. You do not need a long cage (and Shimano actually doesn’t make it for road 11sp). Maybe your rear derailleur isn’t oriented correctly. The B-link of the RD should be almost horizontal.~~
Edit: OP updated original post… it looks like RD is actually short cage 5800, so a new RD will be needed as mentioned by others.
updated OP with photos
Your chain is too long and your b-limit screw is badly adjusted so the top jockey wheel is too close to the cassette. Also, make sure that the derailleur is correctly mounted so the b-limit screw is pressing on its stop.
Looks like your chain is on backwards too, though that’s probably not the issue.
That looks like an RD 5800 GS, so you’re looking at the wrong specification. What is the number visible on the back of the RD?
This is a good link: [https://www.reddit.com/r/bikewrench/comments/ob3ibw/1130_or_1132_cassette_with_105_5800_short_cage/](https://www.reddit.com/r/bikewrench/comments/ob3ibw/1130_or_1132_cassette_with_105_5800_short_cage/)
`The bigger problem is the chainwrap capacity, or the max difference in teeth across which the derailleur can maintain tension. The RD-5800-SS is listed with a capacity of 33T. Assuming that you’re using a front chainring setup of 50/34 or 52/36 with a 16T difference, that leaves you only a 17T difference between the low and high sprockets, which would top out at 11-28.`
`In my experience, going 1-2T above Shimano’s rated capacity is usually uncomfortable but doable – meaning you could probably go to 11-30, putting you at 16T + 19T = 35T capacity. 11-32 would out you at 16T + 21T = 37T capacity, which is 4 over Shimano’s rating and most likely will not work.`