Shimano 11sp groupset compatibility

Triathlon Forum
1

My gravel bike currently has a Shimano Ultegra 6800 11sp drivetrain, including an RD-6800 SS (short cage) rear derailleur & CS-6800 11-28 cassette.

I’ve got a few really hilly gravel races planned for next Spring, and feel like a switch to an 11-32 cassette would be a benefit. However, looking at the tech specs, it appears this is also going to require a switch to a long cage (GS) rear derailleur.

I see that the new 105 5800 group has both long cage rear derailleur & 11-32 cassette options, and the prices are considerable less. (There are no teeth differences in the individual cassette cogs, either.)

I’m having trouble finding the weight differences between the individual components. But, I’m not much of a weight weenie, anyway.

So, my questions are…

  1. Are the 105 RD-5800 GS rear derailleur & CS-5800 11-32 cassette fully compatible with my current 6800 drivetrain?

  2. Will I notice the performance difference “stepping down” to 5800 from my current 6800 (in either the rear derailleur or the cassette)?

Thanks.

2

  1. No

  2. No

The new 105 is really good. You may think you notice a difference, it’s your mind. If you set it up properly, you won’t be able to blame a crappy performance on that darned crappy 105…

3

  1. No

  2. No

The new 105 is really good. You may think you notice a difference, it’s your mind. If you set it up properly, you won’t be able to blame a crappy performance on that darned crappy 105…

So… Did you mean to answer “yes” to the first questions, then?

4

Yes I should have said yes. Had a didifferent question in my head than you asked.

5

I think there have been records of people getting the 11-32 to work well on a short cage. You may want to try that first to save some $$$

6

Ultegra 6800 also has a long cage (technically “medium cage”) derailleur. If you google “5800 derailleur weight” and then “6800 derailleur weight” it appears that The difference in weight between that and 5800 appears to be about 35 grams (about 1.2 ounces) so that’s not gonna be much of a consideration.

Likewise, you will not notice a difference in performance I think.

7

i want to know if anyone has come up with a travel agent or alt routing that will make 11 spd shifters work with 10 spd cassettes (with either a 10spd RD or 11 spd RD. or heck). would love to upgrade some shifters, but wanta keep my 10spd wheels and cassettes (yes, i know i could just drop a cog on an 11spd and use the limits, but i dont want to do that since i have a bunch of 10spd cassettes). :slight_smile:

8

You can use a short cage derailleur with a 32. Just don’t cross chain the big rear cassette cog with the big front chainring.

9

You could also go up to at least 30 teeth with your existing short-cage derailleur and even cross chain, if necessary. I use an 11-speed, SRAM, 11-30 cassette

10

i want to know if anyone has come up with a travel agent or alt routing that will make 11 spd shifters work with 10 spd cassettes (with either a 10spd RD or 11 spd RD.

The pull ratio is different with 11sp Shimano so you should do the shifters and RD at the same time. Add the FD too unless you don’t want the trim to work. Don’t ask how I know a 10sp RD won’t work with 11sp shifters. I’m not sure why you don’t want to invest in a few $30-35 5800 cassettes from Ribble.

11
  • i want to know if anyone has come up with a travel agent or alt routing that will make 11 spd shifters work with 10 spd cassettes (with either a 10spd RD or 11 spd RD. or heck). would love to upgrade some shifters, but wanta keep my 10spd wheels and cassettes (yes, i know i could just drop a cog on an 11spd and use the limits, but i dont want to do that since i have a bunch of 10spd cassettes). :slight_smile: *

You’d be wanting a jtek shiftmate: http://jtekengineering.com/shiftmate.php

I asked if they were going to offer any that match some S11 options, and they said they were working on it. One big issue is that since Shimano changed the geometry of the 11spd derailleurs, it creates extra perturbations. I have no idea how big the difference is. It’s possible that one of their shiftmates already works for what you want, but I don’t know what the cable pull is on the S11 shifters.

One thing you can do is go with Campy shifters. They are comparatively cheap for what you get. Chorus carbon can be had for ~$200 at UK shops. You can get a shiftmate that will work with S10 cassettes and Sh8-10 derailleurs. I’m personally waiting to see if they make one that will shift 11spd cassettes with Sh8-10 derailleurs and C11 shifters. Not holding my breath though. I could always just get a C11 rear derailleur, but I’m fond of my old Dura Ace 9spd ones.