Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

Di2 thinks in wrong cog

Notices
Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

Di2 thinks in wrong cog

Old 05-28-22, 08:19 PM
  #1  
kbreitsprecher
Newbie
Thread Starter
 
Join Date: May 2020
Posts: 4
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Di2 thinks in wrong cog

My bike won't shift into the two smallest cogs in the rear when it is in the large chain ring up front.

When I connect it to e-tube, it "thinks" it is in the smallest cog. It shifts fine into the other cogs going up and back down aside from those bottom two cogs.

I have tried the crash recovery mode, and it shifts up, hits the largest cog and stops. When it hits that cog, it thinks it is 2 from the top.

The bike shop checked the derailleur hanger and it is straight and didn't need adjustment.

I adjusted the offset to +and -16 and the best I can get it is to one away from the bottom. But I don't think that is a reasonable solution.

I would like to just reset cog it thinks its in, but I can't seem to figure this out. The local shop has never seen this and tried everything they could think of, but they can't seem to get any farther than I have.

Edit: There was a comment about a spacer on the cassette. However, The bike is using the original cassette that has never been off the wheel, and the wheel came off the bike, and until the other day it shifted flawlessly.

Any help would be appreciated.

Last edited by kbreitsprecher; 05-29-22 at 06:25 AM. Reason: Adding Information
kbreitsprecher is offline  
Old 05-29-22, 01:26 PM
  #2  
Iride01 
more daylight today!
 
Iride01's Avatar
 
Join Date: Jul 2017
Location: Mississippi
Posts: 12,174

Bikes: Tarmac Disc Comp Di2 - 2020

Mentioned: 43 Post(s)
Tagged: 0 Thread(s)
Quoted: 4991 Post(s)
Liked 3,500 Times in 2,427 Posts
Depending on your rear cassette size, Di2 when in the big front will not shift to the two smallest tooth cogs. Your bike shop guy should know that. Embarrass him me thoroughly. Unless you do have the configuration that allows shifting to all the rear cogs.

I think you have to have less than 28 teeth on your biggest rear cog for it to shift to them. You can fool it by just telling it you have the smaller cassette size in e-tube, but then you might have more slack in your chain when going to those cogs and shifting performance will be affected or maybe you'll drop a chain more often.


Knowing exactly what model Di2 you have might help too. I'm just giving you my R8070 Di2 experience off the top of my head.


EDIT.... I goofed. See my pitiful excuse in later reply!

Last edited by Iride01; 05-29-22 at 04:21 PM.
Iride01 is offline  
Likes For Iride01:
Old 05-29-22, 02:01 PM
  #3  
Koyote
Senior Member
 
Join Date: Sep 2017
Posts: 6,520
Mentioned: 35 Post(s)
Tagged: 0 Thread(s)
Quoted: 5937 Post(s)
Liked 9,002 Times in 3,893 Posts
Originally Posted by Iride01 View Post
Depending on your rear cassette size, Di2 when in the big front will not shift to the two smallest tooth cogs. Your bike shop guy should know that. Embarrass him thoroughly.
umm, it's not the bike shop guy who should be embarrassed here.


When in the big chainring, Di2 should shift to every single cog in the cassette.
Koyote is online now  
Likes For Koyote:
Old 05-29-22, 02:14 PM
  #4  
katyjcrow
Member
 
Join Date: Apr 2015
Posts: 25
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Likes: 0
Liked 2 Times in 2 Posts
Go to bettershifting.com. This guy know everything about Di2. Yes, on the big ring, it should shift to every cog.
katyjcrow is offline  
Likes For katyjcrow:
Old 05-29-22, 02:18 PM
  #5  
Koyote
Senior Member
 
Join Date: Sep 2017
Posts: 6,520
Mentioned: 35 Post(s)
Tagged: 0 Thread(s)
Quoted: 5937 Post(s)
Liked 9,002 Times in 3,893 Posts
Originally Posted by katyjcrow View Post
Go to bettershifting.com. This guy know everything about Di2. Yes, on the big ring, it should shift to every cog.
Or just tag TerryDi2C in this thread. If anyone at bf has a solution, it'll be him!
Koyote is online now  
Likes For Koyote:
Old 05-29-22, 04:30 PM
  #6  
Iride01 
more daylight today!
 
Iride01's Avatar
 
Join Date: Jul 2017
Location: Mississippi
Posts: 12,174

Bikes: Tarmac Disc Comp Di2 - 2020

Mentioned: 43 Post(s)
Tagged: 0 Thread(s)
Quoted: 4991 Post(s)
Liked 3,500 Times in 2,427 Posts
Durn, I hate it! I was stupid when I answered earlier. My feeble excuse is that I must have been delirious from the heat and sun after helping my wife rip out the early spring flowers out of the front flower beds and put in the late spring and summer flowers. We'd just finished and this was one of the first threads I read when getting in out of the sun.

Little while later when out for my 32 mile ride, on the first false flat where I like to get up as much speed as I can for a mile this thread suddenly was foremost in my mind. I panicked and thought about heading home immediately to correct my mistake, but then said fudge it. Only like little Ralphie, it wasn't fudge.

So have at it. I accept my shame willingly. Just glad most of you others must have still been out riding and I got to address my stupidness before too many saw it in all it's glory... or lack thereof!. <grin>
Iride01 is offline  
Likes For Iride01:
Old 05-29-22, 06:29 PM
  #7  
Koyote
Senior Member
 
Join Date: Sep 2017
Posts: 6,520
Mentioned: 35 Post(s)
Tagged: 0 Thread(s)
Quoted: 5937 Post(s)
Liked 9,002 Times in 3,893 Posts
Originally Posted by Iride01 View Post
Durn, I hate it! I was stupid when I answered earlier. My feeble excuse is that I must have been delirious from the heat and sun after helping my wife rip out the early spring flowers out of the front flower beds and put in the late spring and summer flowers. We'd just finished and this was one of the first threads I read when getting in out of the sun.

Little while later when out for my 32 mile ride, on the first false flat where I like to get up as much speed as I can for a mile this thread suddenly was foremost in my mind. I panicked and thought about heading home immediately to correct my mistake, but then said fudge it. Only like little Ralphie, it wasn't fudge.

So have at it. I accept my shame willingly. Just glad most of you others must have still been out riding and I got to address my stupidness before too many saw it in all it's glory... or lack thereof!. <grin>
I knew it was just a silly mistake!
Koyote is online now  
Old 05-30-22, 07:14 AM
  #8  
Barry2 
LRP=HR
 
Join Date: Sep 2019
Location: SF Bay Area
Posts: 1,643

Bikes: Holdsworth 1979 Special, C-dale 1993 MT3000 Tandem & 1996 F700CAD3, Cervelo 2022 R5 & 2018 R3, JustGo Runt, Ridley Oval, Kickr Bike 8-)

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 638 Post(s)
Liked 815 Times in 474 Posts
My silly guess, we all get one, right!

These is a spacer between the cassette and hub that just shouldnt be there.

Barry
Barry2 is offline  
Old 05-30-22, 08:54 AM
  #9  
Iride01 
more daylight today!
 
Iride01's Avatar
 
Join Date: Jul 2017
Location: Mississippi
Posts: 12,174

Bikes: Tarmac Disc Comp Di2 - 2020

Mentioned: 43 Post(s)
Tagged: 0 Thread(s)
Quoted: 4991 Post(s)
Liked 3,500 Times in 2,427 Posts
Is your bike shop an authorized Shimano dealer or service center? If so, they should be able to get on the phone with Shimano and figure this out.

For DIY, I'd go back through the DM for it's installation and make certain every i is dotted and t crossed.

https://si.shimano.com/api/publish/s...010-01-ENG.pdf

https://si.shimano.com/#/en/search/S...8150&type=ROAD


Chain line might be an issue here if you are installing a group set made for road on a mountain bike or vice versa.
Iride01 is offline  
Likes For Iride01:
Old 05-30-22, 09:08 AM
  #10  
Barry2 
LRP=HR
 
Join Date: Sep 2019
Location: SF Bay Area
Posts: 1,643

Bikes: Holdsworth 1979 Special, C-dale 1993 MT3000 Tandem & 1996 F700CAD3, Cervelo 2022 R5 & 2018 R3, JustGo Runt, Ridley Oval, Kickr Bike 8-)

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 638 Post(s)
Liked 815 Times in 474 Posts
Ok, let’s go really basic

if you remove the wheel, does the RD now move as expected, all 11 positions (10 moves) ?

Barry
Barry2 is offline  
Likes For Barry2:
Old 05-30-22, 12:46 PM
  #11  
TerryDi2C
Di2 fanatic
 
TerryDi2C's Avatar
 
Join Date: Aug 2019
Location: The Netherlands
Posts: 132
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 49 Post(s)
Liked 57 Times in 36 Posts
I also sent this via email, but thought I might as well reply to the thread as well ;-).

Sometimes a Di2 rear derailleur is just off by 2-3 gears. It doesn't happen often, but it does happen. There is no real way to fix this. You cannot use E-Tube Project 3.4.5 / 4.0.4 / 5 or the SM-PCE1 / SM-PCE02 to fix this.
I don't know whether or not this is possible with E-Tube Project OEM, but since no one other than factories has access to that it doesn't really matter .

Shimano's method to fix derailleurs that are off by 2+ is to replace them. Usually they'll also replace them if it's out of warranty.

A derailleur hanger or frame that are slightly out of spec (too thick or too thin) is also a possibility... but you would then end up with a derailleur offset one gear at most. Two seems a bit excessive.

Since a bike shop has already looked at the issue it's pretty safe to say that the hanger is straight and that the derailleur is installed correctly. They should've called Shimano though, and I think that is the next step to take ;-)
TerryDi2C is offline  
Likes For TerryDi2C:
Old 05-30-22, 04:10 PM
  #12  
Koyote
Senior Member
 
Join Date: Sep 2017
Posts: 6,520
Mentioned: 35 Post(s)
Tagged: 0 Thread(s)
Quoted: 5937 Post(s)
Liked 9,002 Times in 3,893 Posts
Originally Posted by TerryDi2C View Post
I also sent this via email, but thought I might as well reply to the thread as well ;-).

Sometimes a Di2 rear derailleur is just off by 2-3 gears. It doesn't happen often, but it does happen. There is no real way to fix this. You cannot use E-Tube Project 3.4.5 / 4.0.4 / 5 or the SM-PCE1 / SM-PCE02 to fix this.
I don't know whether or not this is possible with E-Tube Project OEM, but since no one other than factories has access to that it doesn't really matter .

Shimano's method to fix derailleurs that are off by 2+ is to replace them. Usually they'll also replace them if it's out of warranty.

A derailleur hanger or frame that are slightly out of spec (too thick or too thin) is also a possibility... but you would then end up with a derailleur offset one gear at most. Two seems a bit excessive.

Since a bike shop has already looked at the issue it's pretty safe to say that the hanger is straight and that the derailleur is installed correctly. They should've called Shimano though, and I think that is the next step to take ;-)
Wow. That is useful info. Im gonna file that away in case I ever have this issue.
Koyote is online now  
Old 05-31-22, 09:01 PM
  #13  
kbreitsprecher
Newbie
Thread Starter
 
Join Date: May 2020
Posts: 4
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by Barry2 View Post
My silly guess, we all get one, right!

These is a spacer between the cassette and hub that just shouldnt be there.

Barry
There is no spacer in there. The cassette has never been off the wheel and it worked flawlessly before the other day.
kbreitsprecher is offline  
Old 05-31-22, 09:16 PM
  #14  
79pmooney
Senior Member
 
79pmooney's Avatar
 
Join Date: Oct 2014
Location: Portland, OR
Posts: 11,243

Bikes: (2) ti TiCycles, 2007 w/ triple and 2011 fixed, 1979 Peter Mooney, ~1983 Trek 420 now fixed and ~1973 Raleigh Carlton Competition gravel grinder

Mentioned: 115 Post(s)
Tagged: 0 Thread(s)
Quoted: 3834 Post(s)
Liked 2,697 Times in 1,761 Posts
This isn't a constructive comment but - every time I see this thread I think of a goofy blues song "Thinking with the Wrong Head", a state of "mind" that has happened to many men! Read those last couple of posts and "hmmm, just maybe the derailleur has gone down that path." Doe this bike have a foxy front derailleur?
79pmooney is offline  
Old 06-01-22, 10:17 AM
  #15  
Iride01 
more daylight today!
 
Iride01's Avatar
 
Join Date: Jul 2017
Location: Mississippi
Posts: 12,174

Bikes: Tarmac Disc Comp Di2 - 2020

Mentioned: 43 Post(s)
Tagged: 0 Thread(s)
Quoted: 4991 Post(s)
Liked 3,500 Times in 2,427 Posts
Originally Posted by kbreitsprecher View Post
There is no spacer in there. The cassette has never been off the wheel and it worked flawlessly before the other day.
Details like that will always be useful to know. Though it probably wouldn't have helped explicitly, it might have changed some opinions offered.

But on the more immediate quest for a solution.... how is that shop doing getting hold of Shimano?
Iride01 is offline  
Likes For Iride01:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell or Share My Personal Information -

Copyright © 2023 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.