DA 9000 crank : other than 34T inner with 50T outer?

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Delorre
Posts: 967
Joined: Sat May 24, 2014 12:09 pm

by Delorre

mattr wrote:I've been running 50/36 with 12/25 for 3 or 4 years.


DA / Ultegra di2? 'Cause on non di2, there seems to be less problem...a lot less forces apply with mechanic shifting!

11.4
Posts: 1095
Joined: Tue May 23, 2006 4:33 am

by 11.4

I've set up both 39/50 and 42/50 on both 6800 and 9000. Because the back side of the 50 tapers, the 39 or 42 end up a little farther from the 50, so when you downshift the chain wants to ride on top of the smaller ring. I never had it jam in between -- the difference isn't that great -- but it definitely rides on top. I readjusted the front shifter a bit and got it to work fine, but the shifting is still not like with the 34. The 9000 does better than the 6800 and predictably there's less misbehaving with the 39 versus the 42. I really wanted the 42/50 to work and tinkered until I basically got decent shifting and no slippage. Chain choice helped -- a KMC gold 11-speed chain tended to hang up more, while an Ultegra chain worked a lot better and was ultimately satisfactory for me. Also, run the chain a few links shorter since you don't have as many teeth difference anyway -- this makes the chain tighter and gets it to pop down into place a little better. Bottom line: I got them to work acceptably -- and with Di2 it was as good as the original 34. With manual shifting it wasn't as good at first but when I reverted to old muscle memory about totally manual non-click shifting, I got it to work fine.

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maxxevv
Posts: 2012
Joined: Wed Feb 09, 2005 4:51 am

by maxxevv

I've run 50/34, 50/36, 52/36 right from the first DA Di2. But I have been running and still running them on a THM Clavicula and Stronglight rings.

Shifting was never an issue. The 50/36 combination has the smoothest shifts comparatively.

11.4
Posts: 1095
Joined: Tue May 23, 2006 4:33 am

by 11.4

maxxevv wrote:I've run 50/34, 50/36, 52/36 right from the first DA Di2. But I have been running and still running them on a THM Clavicula and Stronglight rings.

Shifting was never an issue. The 50/36 combination has the smoothest shifts comparatively.


Unfortunately 9000 cranks have some particular issues that aren't shared with other cranksets when it comes to compatibility. I have a couple Dura Ace 7950 cranksets that are great for versatility and I keep them for that reason. For 6800 or 9000 cranksets, unless you just do a couple flat chainrings and forsake the hollow large rings that help make the Dura Ace cranksets so superb in shifting, you have to deal with these problems. One can make it work, almost as well as the original, but it isn't something I'd swap back and forth for a particular race or anything like that -- it takes some love and preparation and getting used to the different shift.

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