Results 1 to 15 of 15
  1. #1
    RoadBikeReview Member
    Reputation:
    Join Date
    Jan 2008
    Posts
    147

    Di2 9070 RD failure on Windmill Century

    I had to abort my century ride today because of a di2 9070 rear derailleur failure. The bike was shifting beautifully until just before the first rest stop. I wasn't pedaling hard. Suddenly, the RD made an uncommanded shift to the smallest cog against the limit screw. I heard clicks and whirls when I commanded shifts but the cage didn't move. Also, I could easily move the RD by hand, which I couldn't before. I went through the post-crash recover reset (although I hadn't even bumped the bike) by holding the button down until the red light flashed and turning the cranks. The derailleur struggled to move. The front derailleur shifted fine. The Garmin was very confused.

    Here's what I think caused the failure. I recently upgraded my Di2 9070 with the the 9150 battery and connectors so I had the bar end recharge port and synchroshift with 9070 FD and RD. I didn't use the synchroshift at all but set manual to 'fast' shifting and noticed crisper shifts. I think the new software imposed loads beyond the limits on the 9070 mechanicals. I guess the RD failed first since it shifts way more often.

    By the way, these 9070 derailleurs are in a mixed system with XG-1190 11-28t cassette, Praxis rings and KMC chain. Not sure how that figures in.

  2. #2
    Darling of The Lounge
    Reputation: Retro Grouch's Avatar
    Join Date
    Apr 2002
    Posts
    3,745
    Sorry to hear about your misfortune. Was the first rest stop still in Los Alamos?

    When I lived in the area, the Windmill was my favorite century. Fairly priced, good route and a wonderful BBQ at the end of the ride.

  3. #3
    RoadBikeReview Member
    Reputation:
    Join Date
    Nov 2009
    Posts
    1,077
    was it a metric century?

  4. #4
    RoadBikeReview Member
    Reputation:
    Join Date
    Jun 2008
    Posts
    7,344
    Charlie's BBQ tri-tip (North end of town). The best anywhere.
    Quote Originally Posted by Retro Grouch View Post
    Sorry to hear about your misfortune. Was the first rest stop still in Los Alamos?

    When I lived in the area, the Windmill was my favorite century. Fairly priced, good route and a wonderful BBQ at the end of the ride.

  5. #5
    RoadBikeReview Member
    Reputation:
    Join Date
    Jul 2013
    Posts
    6,359
    your mixed system is identical to what I run.. chain/cassette etc.. I don't have any issue. The one time my RD did not work in the past is when I tagged a huge rock in the pace line... nearly crashed and twisted my levers slightly in on the bars... the cable into the levers was loose under the tape and I was stuck in the 14 for the rest of the ride.

  6. #6
    Adorable Furry Hombre
    Reputation: Marc's Avatar
    Join Date
    Jan 2005
    Posts
    23,877
    Hmmm your scenario sounds a bit similar to one I had on Independence Day.

    My Di2 bigfoot rig (R785 shifters/9070 FD/6870GS RD....46/30 crank with 11-32 cassette)....did a synchro shift down-gearing, and some terrible noise and came to a quick halt...RD had shifted into the spokes enough to ruin the mech and ruin the hanger. According to my Di2 MT800 display unit the RD SHOULD have been in the 4th cassette cog, and not overshifted.


    The synchro down-shift is important as the FD was shifting down....but the RD should have shifted 3 gears up...and instead overshifted the cassette into the wheel. Admittedly I'm not sure that the RD limit screws were still set properly. But even if they weren't, the RD should have been moving in the opposite direction that it went. I still cannot explain it.
    "‘Photograph me on horseback,’ wrote Teddy Roosevelt in 1908. ‘Tennis, no. And golf is fatal.’ "

  7. #7
    RoadBikeReview Member
    Reputation:
    Join Date
    Jan 2008
    Posts
    147
    Quote Originally Posted by factory feel View Post
    was it a metric century?
    You mean the one I didn't do? I started with a group on the full century but only got out about 10 miles, just before the first rest stop, when the derailleur failed.

  8. #8
    RoadBikeReview Member
    Reputation:
    Join Date
    Jan 2008
    Posts
    147
    Quote Originally Posted by Marc View Post
    Hmmm your scenario sounds a bit similar to one I had on Independence Day.

    My Di2 bigfoot rig (R785 shifters/9070 FD/6870GS RD....46/30 crank with 11-32 cassette)....did a synchro shift down-gearing, and some terrible noise and came to a quick halt...RD had shifted into the spokes enough to ruin the mech and ruin the hanger. According to my Di2 MT800 display unit the RD SHOULD have been in the 4th cassette cog, and not overshifted.


    The synchro down-shift is important as the FD was shifting down....but the RD should have shifted 3 gears up...and instead overshifted the cassette into the wheel. Admittedly I'm not sure that the RD limit screws were still set properly. But even if they weren't, the RD should have been moving in the opposite direction that it went. I still cannot explain it.
    I tried the synchroshift and really didn't like it. I was constantly wondering when the FD would shift. I hesitated on shifts when I didn't need to. Plus, I didn't like the way it took me all the way to 25t cog in the big ring before shifting in front. I like it totally manual but set to fast.

  9. #9
    RoadBikeReview Member
    Reputation:
    Join Date
    Oct 2014
    Posts
    2,327
    Quote Originally Posted by tantra View Post
    I tried the synchroshift and really didn't like it. I was constantly wondering when the FD would shift. I hesitated on shifts when I didn't need to. Plus, I didn't like the way it took me all the way to 25t cog in the big ring before shifting in front. I like it totally manual but set to fast.
    I didn't care much for full syncro either, although if you use a Garmn, you can set it up to warn you the next right hand shift will be the FD.

    I ended going with semi-syncro with two compensating shifts. and now that I have a few rides with it, I like it and will stick with it for a while...

    I like being in control of when the FD shifts (i.e. no surprises).... And I don't use a Garmin head unit.

  10. #10
    RoadBikeReview Member
    Reputation:
    Join Date
    Jul 2012
    Posts
    787
    Quote Originally Posted by tantra View Post
    I tried the synchroshift and really didn't like it. I was constantly wondering when the FD would shift. I hesitated on shifts when I didn't need to. Plus, I didn't like the way it took me all the way to 25t cog in the big ring before shifting in front. I like it totally manual but set to fast.
    Can't you set it up so it shifts when and where you want it to?
    I'd like to try it, but means buying a bunch of bits just to see how I like it, so not any time soon..
    All the gear and no idea

  11. #11
    Adorable Furry Hombre
    Reputation: Marc's Avatar
    Join Date
    Jan 2005
    Posts
    23,877
    Quote Originally Posted by tantra View Post
    I tried the synchroshift and really didn't like it. I was constantly wondering when the FD would shift. I hesitated on shifts when I didn't need to. Plus, I didn't like the way it took me all the way to 25t cog in the big ring before shifting in front. I like it totally manual but set to fast.
    S1 you tell it when to FD shift. S2 is predetermined points in the cassette where it auto FDs.....set the predetermined points in E-Tube. You can also tell it to chirp at you when your next shift will throw the FD.
    "‘Photograph me on horseback,’ wrote Teddy Roosevelt in 1908. ‘Tennis, no. And golf is fatal.’ "

  12. #12
    RoadBikeReview Member
    Reputation:
    Join Date
    Jun 2017
    Posts
    2

    Di2 9070 RD failure on Windmill Century

    Quote Originally Posted by Marc View Post
    S1 you tell it when to FD shift. S2 is predetermined points in the cassette where it auto FDs.....set the predetermined points in E-Tube. You can also tell it to chirp at you when your next shift will throw the FD.
    Actually S1 and S2 are just two slots or memory positions. You can program either slot to any synchronous or semi-synchronous configuration you want. For example, I have S1 programmed to a configuration I call SemiU2D1. It's semi- synchronous with the rear derailleur adjusting by 2 when I move up to the big chainring, and the the rear adjusting by 1 when I move down to the small chainring. In S2, I have another configuration which I call SemiU2D2 (which is also the default semi-synchronous config).

    On the road, I can cycle through Manual, S1, and S2 by double tapping the Di2 control box's button.

    I didn't like full synchronous no matter how much I played with the shift points, so I stick with semis in S1 and S2.

  13. #13
    RoadBikeReview Member
    Reputation:
    Join Date
    Nov 2009
    Posts
    1,077
    there was a rest stop before ten mile marker?

  14. #14
    RoadBikeReview Member
    Reputation:
    Join Date
    Jul 2013
    Posts
    6,359
    Quote Originally Posted by factory feel View Post
    there was a rest stop before ten mile marker?
    irrelevent ? Often the shortest rides will be something like 25miles..so yes there can be rest stops around that mile mark. Not everyone doing this things is in shape remember.

  15. #15
    RoadBikeReview Member
    Reputation:
    Join Date
    Nov 2009
    Posts
    1,077
    Quote Originally Posted by spdntrxi View Post
    irrelevent ? Often the shortest rides will be something like 25miles..so yes there can be rest stops around that mile mark. Not everyone doing this things is in shape remember.
    oh i just wondered

Similar Threads

  1. Wires compatibility between Di2-7970 and Di2-9070 ?
    By Pierre in forum Components, Wrenching
    Replies: 1
    Last Post: 08-20-2013, 08:05 AM
  2. dura ace 9000 9070 DI2
    By progolferv1 in forum Components, Wrenching
    Replies: 5
    Last Post: 11-04-2012, 01:26 PM
  3. Sprinter buttons for Di2 9070?
    By nagge in forum Shimano
    Replies: 0
    Last Post: 10-03-2012, 10:54 AM
  4. Di2 9070 IMO Good Compromise!
    By supraholic in forum Components, Wrenching
    Replies: 11
    Last Post: 06-12-2012, 07:24 PM
  5. Windmill and clogs
    By Malcog in forum The Lounge
    Replies: 3
    Last Post: 10-16-2006, 08:14 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •