Dura-Ace DI2 R9250 gravel gearing

[la85]

Hey all,

In the process of purchasing a Specialized Crux custom. It's running Dura-Ace R9250 50/34t chainring with a 11-34 cassette.

Can this run a smaller chainring? Larger cassette?
The gearing might be fine but wouldn't mind some insight into minimum chainring and max cassette size.

Currently on a GRX DI2 48/31t with a 11/34 cassette.

Cheers

[la85]

Any shimano 12 speed 11-36 cassettes available apart from the 105 or rotor (bad reviews?)?

[pdlpsher1]

I haven't tried running a stock GRX crank with a 9250 FD, but I do have a Rotor crank and a P2M PM with a standard 'road' short axle, and shifting is great. I've used both 11-speed and 12-speed GRX chainrings, and now I'm on the 12-speed GRX 48/31 rings. Shifting is great on both but I think it's slightly better on the 12-speed rings. I just recently put a 11-36 cassette on as well and it's working great. I didn't test it with the stock 9250 RD. I just assumed it needed a longer cage to work optimally. I transplated a 8150 RD cage onto the 9250. Everything works great. The chain is a bit noisy on the 48-32 and 48-36 combos. But I'm not in those gears for very long. So to summarize this my setup.

48/31 12-speed chainrings on a Rotor/P2M crankset.
9250 FD and RD, with the RD having a 8150 cage.
11-36 12-speed cassette

[la85]

I haven't tried running a stock GRX crank with a 9250 FD, but I do have a Rotor crank and a P2M PM with a standard 'road' short axle, and shifting is great. I've used both 11-speed and 12-speed GRX chainrings, and now I'm on the 12-speed GRX 48/31 rings. Shifting is great on both but I think it's slightly better on the 12-speed rings. I just recently put a 11-36 cassette on as well and it's working great. I didn't test it with the stock 9250 RD. I just assumed it needed a longer cage to work optimally. I transplated a 8150 RD cage onto the 9250. Everything works great. The chain is a bit noisy on the 48-32 and 48-36 combos. But I'm not in those gears for very long. So to summarize this my setup.

48/31 12-speed chainrings on a Rotor/P2M crankset.
9250 FD and RD, with the RD having a 8150 cage.
11-36 12-speed cassette

Thanks mate. What cassette are you using?

[pdlpsher1]

The Shimano 105 11-36. Yes, it’s a brick but shifting is great.


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[la85]

So I've found a Stone chainset - 48/33t that will fit 9200 dura ace.

Has anyone had any luck with Stone chainrings?

I've read a few reviews and they all read well.

Will the FD 9250 go low enough to do the 48/33?

Is a chainring 34t v 33t really going to be noticeable? Ie in the granny gear on the 34t cassette?

Not sure if it's worth all the effort.

Thanks heaps for everyone's help!

[la85]

Anyone else running dura ace on their gravel bike? Is no clutch a real problem?

[satanas]

1. Will the FD 9250 go low enough to do the 48/33?
2. Is a chainring 34t v 33t really going to be noticeable? Ie in the granny gear on the 34t cassette?
3. Is no clutch a real problem?

1. Yes, the Crux frame has a clamp-on FD mount so you can put it where you like
2. Noticeable - maybe, but not by much. Different cranks with a smaller BCD (and thus possible chainring) are needed to make a significant difference
3. Depends on your POV. Bear in mind that nobody had clutched RDs prior to XX1, and MTBs survived okay without them for decades. And of course there's lots of CX done on DA too...

[la85]

1. Will the FD 9250 go low enough to do the 48/33?
2. Is a chainring 34t v 33t really going to be noticeable? Ie in the granny gear on the 34t cassette?
3. Is no clutch a real problem?

1. Yes, the Crux frame has a clamp-on FD mount so you can put it where you like
2. Noticeable - maybe, but not by much. Different cranks with a smaller BCD (and thus possible chainring) are needed to make a significant difference
3. Depends on your POV. Bear in mind that nobody had clutched RDs prior to XX1, and MTBs survived okay without them for decades. And of course there's lots of CX done on DA too...

Thanks mate!

[boots2000]

Dura Ace with GRX in back? Like this build? https://www.youtube.com/watch?v=3oy5yuSOzKE