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Discussion Starter · #1 ·
The Mrs is "getting up there" and needs low gears. She is riding a 9-speed Dura Ace triple setup which has a 53-39-30 front rings and I put an 9-speed XTR rear derailleur on the back with an 11-32 mountain cassette and she uses all the gears (well, probably not the 53x11).

She'd like to move to electronic and while a 50x34 compact would be fine, she'd almost need an 12x36 or the 11x40. The problem, of course, is that I don't see any way to make this work. "Back in the day" the 9 speed road and mountain derailleurs pulled the same amount of cable, so mixing/matching road/mountain was easy.

She likes the high zoot gear, so running a low-end groupset on her high-end bike isn't going to work.

So, how low can we go? If staying mechanical, does that help with her options?

Forever a Student
4,963 Posts
There's plenty of bikes now wanting to do what you want.

Think the Open U.P. type of bike, drop bars, road cranks and MTB in the back.

Here's this chart:

Text Photograph White Line Font

To sum this up:

Road Shifters (6770 are fine)
Road Junction Box
Road 50/34 Cranks
MTB Front Di2 Mech
MTB Rear Di2 Mech
MTB Cassette

So the deal is that you have to use the MTB front and rear mechs, can't use a road front mech.

On most bikes it works but on some bikes the front mech cage can't reach inboard enough, causing it to rub the chain in the climbing gears. So it's frame dependent if it works flawlessly or not, I can't say for sure, you probably can't either unless you try.

But it's possible and you can run the 50/34 up front and 11-40 or 11-42 in the back.

Adorable Furry Hombre
30,963 Posts
Why stop at 50x34? There are several 48x32 and 46x30 cranks to choose from (FSA, White Industries, Praxis, Sugino etc). How often will she really need that 50T front gear? And by going lower crank you can keep tight(er) cassette spacing.
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