11/25t cassette on a medium cage shimano derailleur (or 11/32 on a short cage)

[echappist]

About to get my new bike, and I bought 8050 med cage derailleur for it (and moving the 6850 short cage onto my TT bike).

After the purchase of the med cage, I realized that my ideal cassette for the TT bike (11/23t or 11/25t) is not listed as compatible with the medium cage, according to Shimano. Why does this matter? B/c I will be mostly riding indoor and prefer the tighter gear ratios on a 11/25t.

So here's the question, just how bad will the performance be (11/25t with my med cage 8050). I know Shimano is very conservative with their tolerance faults, etc., so is this more a situation of it could very well work, but they won't say it for fearing it may not work in all situations? Also, I remember people saying that they got their short cage 6850 derailleurs to work with a 11/32t, even though the 6850 is rated for 30t. Push comes to shove, which of these non-ideal situation would be more preferable?

[Tony]

You can use a wolf tooth roadlink, problem solved.

https://www.jensonusa.com/search?q=w...oth%20roadlink

[mattsurf]

Originally Posted by echappist

About to get my new bike, and I bought 8050 med cage derailleur for it (and moving the 6850 short cage onto my TT bike).

After the purchase of the med cage, I realized that my ideal cassette for the TT bike (11/23t or 11/25t) is not listed as compatible with the medium cage, according to Shimano. Why does this matter? B/c I will be mostly riding indoor and prefer the tighter gear ratios on a 11/25t.

So here's the question, just how bad will the performance be (11/25t with my med cage 8050). I know Shimano is very conservative with their tolerance faults, etc., so is this more a situation of it could very well work, but they won't say it for fearing it may not work in all situations? Also, I remember people saying that they got their short cage 6850 derailleurs to work with a 11/32t, even though the 6850 is rated for 30t. Push comes to shove, which of these non-ideal situation would be more preferable?

8050 is fine on an 11-23

The only downside I can possibly see is that the 8050 medium cage is slighly heavier than necessary, and the chain is slightly longer than you absolutely require, so you could save a few grams

My favourite cassette is 12-25 for the reasons you describe, Shifting performance on mechanical R8000 is just as good as the short cage 6870 di2 on my other bike

[Gummee]

Originally Posted by echappist

Push comes to shove, which of these non-ideal situation would be more preferable?

The word from Shimano is that the knuckles/cage/prallelogram on the long cage road derailleurs is optimized for the bigger gears and jumps of the larger cassettes.

IDK about Di2, but my short cage 6800 works pretty well with an 11-32 w no link or anything else. Small amount of grumbling in the 32, but I'm rarely there, so put up with it for the bailout gear.

So.... the long cage will probably work acceptably on the small cassette, but as you say, OP, Shimano is notoriously conservative when it comes to this stuff.

Try it and see is the best bet

M