11-34 / 50-34 on a DA9150? Anyone done it?

[Cannoli]

Has anyone run an 11-34 cassette with a 50/34 front chainring combo on a Dura Ace 9150? I currently have an 11-32 on my wife's bike and was thinking about fitting an 11-34 for her bike for an upcoming 100 mile / 10k' ride. Thoughts?

(I'm trying to avoid buying an Ultegra 8050 GS if I can help it, but will if that's the necessary next step)

[fruitfly]

Yes, I regularly do this. I have to allow more of a gap than usual between the upper jockey wheel and the cassette to ensure that the 34 shift is crisp and stable.

[Cannoli]

Yes, I regularly do this. I have to allow more of a gap than usual between the upper jockey wheel and the cassette to ensure that the 34 shift is crisp and stable.

Nice! Good to know. Any other drawbacks to this setup (besides weight, of course)?

[calleking]

Not sure if there is any difference between 9150 and R8050 but I converted my CX for gravel and ran 50/34 with 11-34 cassette. Good allround gearing for most riding but the most extreme climbs.

Worked flawlessly through heaps of Scandinavian snow, mud and just about anything you could imagine. I also had to adjust the gap between the cassette and the jockey wheel but other than that it was just set and forget.

[Cannoli]

Not sure if there is any difference between 9150 and R8050 but I converted my CX for gravel and ran 50/34 with 11-34 cassette. Good allround gearing for most riding but the most extreme climbs.

Worked flawlessly through heaps of Scandinavian snow, mud and just about anything you could imagine. I also had to adjust the gap between the cassette and the jockey wheel but other than that it was just set and forget.

Short cage 8050?

[Mocs123]

I think Shimano states the Dura Ace 9050 rear derailer only goes to 11-30 but it's well known it works with 11-32. You're the first person I know thats tried 11-34 but hopefully it works. I actually replaced my Dura Ace 9070 rear derailer with Ultegra 8050 rear derailer so I could use 11-32.

[spdntrxi]

^ I've been able to use 9070 with a 11-32 on a number of bikes I've had in my stable, but had 1 or 2 that 11-30 was the max. Frame dependent. My wife's bike is like that now...9070 w/11-32. (older rim brake madone)

[takolino]

An issue i've experienced is reduced crispness at the high end of the cassette. I'm using R9050 on a 9-32 cassette and the 9-10 shift is pretty sluggish after B-screw adjustment to clear the 32t. I realize that they spec 11t for the highest gear so I'm not complaining. Gap on the 9t is huge.

Chain selection may also have an effect. Shimano chains seem to be designed to catch the next cog more efficiently as they are designed assymetrically. Try a shimano chain if it becomes too sluggish.

[alcatraz]

When trying to clear a big cog, the compromise is shift quality. The derailleur has a fixed angle of travel. The greater the mismatch, the greater the distance to the cassette has to be. As such the chain deflection becomes too great to get as crisp a shift. The small cogs usually suffer first. But the same can be said the opposite way. Trying to run an 11-23t cassette on a mid cage GS derailleur is also a mismatch.

Shift quality is subjective so some might advise against, some might not.

I'd say for racing it's a bad idea but for casual riding, perfectly fine.

A new chain can mask some issues that are waiting down the road. As the chain wears in it deflects more and more which is bad for shifting.

[wheelsONfire]

I use 11-36 with my 6870 RD. I drilled a new hole for the RD tension spring and increased the tension.
Works great!

[Cannoli]

Thank you, all. Great feedback. I ordered an 11-34 cassette, which will be here soon. Once installed and she can take it for a ride, I'll report back. This is definitely not something that she'll run all the time, just for the long days in the saddle with lots of climbing. I'll swap back to 11-32 for her every day riding.

[alasamerlin]

I do it with Ultegra R8000, I think the same cage lenght
Usually I ride 11-30 or 11-32 cassette, but for steep and long ride
inthe Alps I tried 11-34and it works very good.

[naylor343]

Alternatively, a 33t chainring with your current 32 cassette will give you a bottom gear of 1.03, equivalent of a 34 ring with a 33 cassette, Sitting exactly in the middle of the two choices you now have. Upside is that if it's just for one ride a TA x110 in 33T is less than half the cost of a R8000 11-34 cassette. Just another option/suggestion.

[markdjr]

I'm running a 11-40 XTR cassette on my 9150 with a longer b screw. It shifts good enough for me, the 11-40 xtr is lighter than ultegra 11-34 and I don't mind saving some matches when things get extra steep and I have the option to spin.

[Cannoli]

I just fitted the 11-34 on my wife's DA 9150 with 50-34 chainrings. After adjusting the B-screw and the front derailleur trim a bit, it shifts very nicely (on the stand). I'll report back after tomorrow's ride.