Ultegra 8150 12 speed rear derailleur .. do they make a short cage now?

[billynyc]

Hi

I'm using a 11-30 cassette on with the long cage, it looks hideous. Do they make a shorter cage version yet? I don't believe they did when I first got it plus I also originally had the 11-34 on there

[Maddie]

There is no short cage from Shimano for 8150 and 9250 derailleurs. I think your only choice is OSPW but they aren't smaller either.

[ooo]

rd-r9250 has a shorter cage than rd-r8150

Dura-Ace cage length is about 94 mm, chain capacity is 37T.
Ultegra cage length is 100 mm, chain capacity is 39T.
https://handsonbike.blogspot.com/2023/09/12-speed-di2-rear-and-front-derailleur.html

[pdlpsher1]

Shimano was able to shorten the 9250 cage since they lock out the two smallest cogs, which effectively increases the wrap capacity of the stock cage by 2 teeth. Putting the shorter 9250 cage on an Ultegra RD is probably OK as long as the cassette is kept to 11-30.

[wltz]

On what kind of mushrooms must one be to accidentally, or intentionally, end up in small-small during normal riding? FWIW I modded my 8150 RD with a 9250 cage, and I'm running 54/39 with an 11-34 cassette without any issues.

[billynyc]

rd-r9250 has a shorter cage than rd-r8150

Dura-Ace cage length is about 94 mm, chain capacity is 37T.
Ultegra cage length is 100 mm, chain capacity is 39T.
https://handsonbike.blogspot.com/2023/09/12-speed-di2-rear-and-front-derailleur.html

Thx!

[billynyc]

rd-r9250 has a shorter cage than rd-r8150

Dura-Ace cage length is about 94 mm, chain capacity is 37T.
Ultegra cage length is 100 mm, chain capacity is 39T.
https://handsonbike.blogspot.com/2023/09/12-speed-di2-rear-and-front-derailleur.html

Thx!

On what kind of mushrooms must one be to accidentally, or intentionally, end up in small-small during normal riding? FWIW I modded my 8150 RD with a 9250 cage, and I'm running 54/39 with an 11-34 cassette without any issues.

I'll try it out thanx

[kofsw4]

On what kind of mushrooms must one be to accidentally, or intentionally, end up in small-small during normal riding? FWIW I modded my 8150 RD with a 9250 cage, and I'm running 54/39 with an 11-34 cassette without any issues.

How much weight did swapping the cages save? Thinking about doing this too

Sent from my CPH2305 using Tapatalk

[wltz]

On what kind of mushrooms must one be to accidentally, or intentionally, end up in small-small during normal riding? FWIW I modded my 8150 RD with a 9250 cage, and I'm running 54/39 with an 11-34 cassette without any issues.

How much weight did swapping the cages save? Thinking about doing this too

Sent from my CPH2305 using Tapatalk

74g vs 49g

[kofsw4]

On what kind of mushrooms must one be to accidentally, or intentionally, end up in small-small during normal riding? FWIW I modded my 8150 RD with a 9250 cage, and I'm running 54/39 with an 11-34 cassette without any issues.

How much weight did swapping the cages save? Thinking about doing this too

Sent from my CPH2305 using Tapatalk

74g vs 49g

Thanks for the super fast reply. I'll give it a go

Sent from my CPH2305 using Tapatalk

[Ritxis]

Back in the day I mounted a 9100 cage that is shorter than the 9250 on an RD-8150 and without problems with a 32 at the back

[Singlish]

Back in the day I mounted a 9100 cage that is shorter than the 9250 on an RD-8150 and without problems with a 32 at the back

Do you ever attempt running an 11-34 with this?

By the same logic, has anyone tried an 8150/9250 cage on 9150 to get a litle extra cassette capacity?

[wltz]

FWIW, the 9150 RD clears 11-32 with the stock B-screw, iirc with at least 2 full turns to spare. I think it will clear 11-34 if you replace the DA B-screw with Ultegra, which is longer, but I guess your shifting in the highest gears will be compromised at this point. In fact, after replacing the 8050 RD (short cage) with the 9150 on my climbing bike, I also replaced my 11-32 Red cassette with an 11-30, because upshifting from 12t to 11t wasn't quite there.

P.S.: the bike has crazy short chain stays at 403mm, so this setup might work better with chain stays meeting the minimum 410 length specified by Shimano. I'm running Rotor Aldhu with a longer axle, which offsets my chainline by 2.5mm outboard and improves shifting in the small cogs.