Short Cage 9250 R Derailleur

[Lelandjt]

Is there an aftermarket short pulley cage for the current Dura-Ace 9250 rear derailleur? I'm thinking less aero drag and weight for setups that don't need the chain capacity*. Coming from DA9000, this derailleur is hard to look at.

*40/54 or 39/53 chainrings, don't cross chain, maybe cut the 30t cog off for an 11spd 11-27t.

[snaxez]

You can get 11-25T or 11-28T from here https://prestacycle.com/products/presta ... 2-12-speed
but I have not seen any short cage for shimano 12 speed. Only OSPW ones.

[Lelandjt]

You can get 11-25T or 11-28T from here https://prestacycle.com/products/presta ... 2-12-speed
but I have not seen any short cage for shimano 12 speed. Only OSPW ones.

Good call on the 11-25t cassette! Hopefully it shifts okay. I'm suprised there isn't a market for a short cage on these derailleurs.

[Hexsense]

11 speed 11-23
and
10 speed 11-21 before that, wasn't sold well at all.

Apperantly, people don't find gear steps on 11 speed 11-25 and 10 speed 11-23 to be lacking.
So I'm not surprised when adding one more cog to the cassette. People decided it's better to keep the existing 11 cogs then add one more at the end rather than adding one to the middle.

Then the cage length follows the extended range of the cassette..

[Lelandjt]

Apperantly, people don't find gear steps on 11 speed 11-25 and 10 speed 11-23 to be lacking.

So Shimano should have made 12spd 11-28. A 30t cog just isn't useful for a lot of riders but that's the smallest they make for their "pro level" group. This is the cassette they expect to be used in time trials. Might as well ditch the front derailleur, something Shimano seems against.

[Hexsense]

Yeah, they should.
11-28 was planned but then canceled.
So instead of
11-12-13-14-15-16-17-19-21-23-25-28
we got
11-12-13-14-15-16-17-19-21-24-27-30

Last 3 cogs has a bit more spread.

[garbageman]

Yeah, they should.
11-28 was planned but then canceled.
So instead of
11-12-13-14-15-16-17-19-21-23-25-28
we got
11-12-13-14-15-16-17-19-21-24-27-30

Last 3 cogs has a bit more spread.

The Dura Ace 11-28 would have been 11-12-13-14-15-16-17-18-19-21-24-28.

[Lelandjt]

The short cage 9000 derailleur easily handles the 11-28 39/53 on my touring bike. They didn't need such a long cage for the 30t. The new cage size is for the 11-34 34/50 users who ride in big/big and small/9th. The rest of us are carrying around more cage and chain than is ideal.

[Hexsense]

9000 series derailleur use offset top pulley.
R9100 and R9200 series RD mount top pulley exactly at the cage rotation point (i.e., 0 offset top pulley).
This slant parallogram with 0 offset top pulley keep distance between top pulley to the cassette cog consistent no matter how the cage rotate (no matter if you are on big ring or small ring).
But it require longer cage for the same chain capacity. It's not a longer cage for no reason. Shimano want consistent top pulley location for shift quality with 2x front rings.

Modern MTB RD are exactly opposite of this though. It use very high top pulley offset from cage rotation point to maximize chain capacity with short cage but such design extreme make it not support 2x chainring anymore.

[Xabi]

Is there an aftermarket short pulley cage for the current Dura-Ace 9250 rear derailleur? I'm thinking less aero drag and weight for setups that don't need the chain capacity*. Coming from DA9000, this derailleur is hard to look at.

*40/54 or 39/53 chainrings, don't cross chain, maybe cut the 30t cog off for an 11spd 11-27t.

Some aftermarket pulley cages are compatible with both 11 and 12 speed Shimano di2.

You could try your luck with Dura ace 9100 pulley cage to check if it fits.