Hasn't happened to me, but here are a few possible causes that come to mind...

• Bad connection between the battery - Try removing the battery and wiping everything down well
• Bad battery - Try swapping batteries
• Bad RD - SRAM Tech Support
  

Reading similar experiences as yours, even if you contact SRAM Tech Support directly, they will direct you to a local bike shop, probably the one you bought eTap from (or the bike if it came with eTap) for troubleshooting/warranty replacement.

I've had a similar issue with my road setup as well. I found going through the pairing process again made it go away. Give that a try!

Recommendations for eTap..... Ensure the Blip box (and sifters too) have clear path or line of sight (LOS) to derailleurs. I cringe when I see people hiding their Blip Box inside of items that are made of metal (Stem?). Water (the human Body is 90% water) and bottles with fluid also can reduce the signal level too.... Just good practice for wireless links.

csontag wrote:

I've had a similar issue with my road setup as well. I found going through the pairing process again made it go away. Give that a try!

Thanks for the suggestion. I paired the derailleur again and I didn't have any issue during my last session. The shop has sent me a prepaid label so I can return the derailleur directly to SRAM, but before I'll do that I will try a few more times to confirm if the problem is fixed.

scca_ita, it's a road setup, not TT.

I had this problem. Its one of your blips that control the rear derailleur. Do you notice if it happens on your try extensions vs your base bar? If you can narrow down which blip is bad, you can get your local bike shop to send in for replacement blip (s).

Mine started the same as you and then eventually stopped shifting from that blip all together.

It's a road setup, not TT. I don't think it' the shifters because I can't shift in any direction when it happens.

Well, re-pairing the derailleur didn't do anything after all, and it stopped shifting again tonight. This time I verified that when the derailleur doesn't want to shift:

1) The LED lights up on the shifter
2) The LED lights up on the rear derailleur (so, it's receiving the signal), but no movement
3) I can still shift the front
4) I'm able to shift by pressing the button located on the rear derailleur. After I've done that, two things happen:

- the net effect of all the shifts that didn't move the derailleur before, suddenly move the derailleur. So it may for example jump multiple sprockets down, if the right paddle was pressed multiple times
- after that, everything works normally again

This is very strange because all this means that the shifters works correctly, the derailleur receives the signal from the shifters, and the motor in the derailleur works correctly. So why does it decide to not move, I have no idea.


So I guess I will send the derailleur back to SRAM... Trying to get a replacement beforehand so I'm not without a bike.

I have the same problem - it's happened to me 3 times. I thought it was battery issues and actually bought spare batteries that I now carry with every ride. Thanks for posting, I'm going to wait for it to happen again and then also log a warranty call. Please update once you receive the replacement to confirm that the problem is resolved?

I got an Etap bike last year and I received a DOA rear derailleur that I had to warranty.

FWIW, my bike is running flawlessly now and the front and rear mech's are working as nicely as I hoped.

When I read the eye-glazing parts lists of people fitting Di2 to bikes, I am very happy with the simplicity of Etap, but I think they have some ways to go on reliability.

Good luck getting it sorted out!

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" I take my gear out of my car and put my bike together. Tourists and locals are watching from sidewalk cafes. Non-racers. The emptiness of of their lives shocks me. "
(opening lines from Tim Krabbe's The Rider , 1978

I'll update the thread but it will take a while. The shop has informed me that it will take 15-20 work days to service the derailleur. So, I will have to buy a new derailleur just to replace the one that will be gone for a month... Pretty pissed at SRAM and at the shop right now.

I've found that lifting the back wheel off the ground while riding actually makes the derailleur work again when it freezes. My guess is that there is some sort of mechanism wakes up the derailleur when you're moving, that is not working properly. So it looks like sometime it goes to sleep, and smashing it wakes it up.

Hi This issue has happened me twice now and also once for someone else. We use the TT setup..blipbox etc. All occasions the RD was replaced.
I found two vids of the issue. Interesting that lifting the wheel fixes it. Actually just pressing the button on the RD fixes it too. Its like the brain believes it has shifted but the mech has not. I have asked SRAM if its a maintenance issue ie dust or something on the mech stopping the shift but no response. Its really frustrating when it happens in a race.
https://www.youtube.com/watch?v=Qsz6Rz8_-Uw

https://www.youtube.com/watch?v=6zEvbSnIaV4

Interesting issue. I have not used eTap but I do find it very interesting and wireless shifting is definitely the future.

Am I correct in thinking that the derailleurs have accelerators in them and its these that wake the system? I'm just wondering (based on the comment about lifting the rear wheel) if there could be a fault with this bit?

Just a thought, I'll reiterate that I have no personal experience with eTap.

Steve

Hi, Yes they have an accelerator which is why the battery runs down on a plane/car.

Id love to hear more on your thoughts on how this is related. I posted this yesterday on Reddit but it shows examples of the problem occurring particularly in the rear. One of these Vids also shows that the brain transmits its gear to the Gamin correctly though it has not changed. The second time it went for me it was after going over ground where dry fine cement was on the road (near a quarry)

I have Etap TT setup. I love it. I have it a year and would find it hard to go back to mechanical. HOWEVER I have sent the rear derailleur back twice for issues where it does not shift when I press the button. I have found other incidences where this happens as well on line (see below). Other people have had a similar experience as Sebi where the front shifted unexpectedly and randomly and/or the rear does the same and it was found to be the blip box. In my case and theirs the units were replaced under warranty but there is something flaky going on with sram etap. I believe in my case the software brain thinks it has shifted but the mech did not. Once I click a few times it eventually comes back and then goes berserk going through all the failed up and down shifts to "catch up" with the brain. There are no firmware updates yet but my suspicion is Sram will start issuing these and correct these problems. I never comment online but this post is very close to mine and my friends experiences so I hope others will join in. I also find Sram users very touchy about taking the plunge and nobody talks about this on line. I wonder if the issues are just TT setup related (ie the Blip Box)???
https://www.youtube.com/watch?v=Qsz6Rz8_-Uw

https://www.youtube.com/watch?v=6zEvbSnIaV4

How charged is your battery?

I've run into issues with my 1x TT eTap (homemade blips):

1. The rear derailleur will all of a sudden shift into the highest gear. The first time this happened was in a race. I popped the battery out/in and it seemed to fix it. It happened a few times throughout the next few months, but I narrowed it down to the battery not being fully charged.

2. I would shift up then and the derailleur would shift up then right back down. This was a combo of indexing and too long of a chain.

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Strava

I really ave no insight into this but just wondered if there were a problem with the sensors flipping in could it cause the unit to go to sleep temporarily, then suddenly wake-up once the sensor kicks in. Thinking about it a bit more, is the FD signal relayed from the RD? if so my theory would be defunct, if not it could account for the FD working but not the RD.

My thinking re the lifted rear wheel was that perhaps this directional movement was able to trigger the sensor and wake the RD. I'm probably talking BS as I don't have eTap nor am I particularly electronically savvy.