Electronic & Hydraulic Shifting (Di2, Ui2, customisations)

Anyone know of any deals on the old first hen Sram red etap?

I've got a bit of a problem. Di2 6800 and the bike worked fine Friday barring the front mech twisting a little due to some lazy maintenance. Yesterday I gave it a clean and when I went to sort the front mech, the rear shifted to the small cog but when I'd sorted the front out, it seemed the rear had stopped working (there's a small amount of movement on the mech when I press the shifter but not enough to move it far). Any idea what the issue might be.

Sounds like you may have gone into crash protection mode. This piece tells you how to clear it.
https://www.google.co.uk/amp/s/road.cc/content/forum/193805-di2-crash-mode-bluffers-guide%3famp

Agree, almost certain that crash protection mode has been triggered.

Do I hold the button down or release it? Tried it but it doesn’t shift up and down the cassette.

Hold the button for 5+ seconds until red light comes on, and turn the pedals

Then release?

Actual instructions start at 1:00.

https://www.youtube.com/watch?v=rUkKqNN7HVI

I saw that. The reason I asked is that when I let go of the button, it goes to red and green and then doesn't move up and down the cassette. I'll unplug the battery and see if that helps.

LBS guy has no idea either. Says it looks like crash mode but it won't seem to come out of it. The mechanic with most experience of di2 is arriving soon so he'll have a go at it then. Stay tuned etc.

If the derailler is prevented from moving in its proper arc it can do this kind of thing. I found this out at the start of TCR last year. It shifted once and then failed to shift again. Seems it had slipped off the B-screw spring stop point when I first fitted it after the flight and then was in an odd position. Removed derailler, refitted it very carefully and it worked again.

If you push the button - does the derailer servo make noise?

Is it in the big ring or little ring?

It'll shift the front ring no problem. The servo makes noise, almost like it's micro adjusting when press the shifters so the connection is there. When I pop back in an hour or so I'll suggest removing and reinstalling the mech. - @hippy

Does the RD actually move? If the red light is on the Junction Box A it could be in fine-adjustment mode. Assuming you've already held that down for 10s or whatever then it's unlikely but possible. If the derailler is making a noise when you push the shifter button, it's not the shifter button failing it's likely trying to move but can't so either something (like my B-screw setup) is preventing it from moving or the unit is fuxxored in some other way internally, but that seems unlikely given not crashy crashy (I assume, not been following conversation).

The reason I asked about big/small is that the newer stuff won't let you use small front ring with two smallest cogs at the back. So, if it's in the small cog, put the chainring into big and try again. It should shift up to the 3rd cog at the back but perhaps it's struggling to move 3 steps at once - again I'd look for loose mount, crooked mount, b-screw not seated properly, twisted anything, etc.

Nah, no crash, probably was a bit eager to get the rear wheel out so maybe banged it a bit hard but nothing that felt like it should have been an issue.

With any luck the senior mechanic will fix it all or declare it's buggered. Tonight I can connect the rear mech to my other bike and see if it shifts that one which I guess will tell me whether it's the mech or the shifter or something else.

And yeah, the mech moves a little. As I said, more like microadjust than anything though

Can you grab the mech and force it to move a little. Like, not enough to snap it but try forcing the parallelogram to move by hand. You've double checked the B-screw stop already? If it moved too far once it can be in a position that won't allow it to move normally. Force it with your hand up the cassette a bit and see if it frees up.
Doesn't have to be on the bike, just make sure it can move.

Once in Transib I dumped the chain from big to little while holding the RD shifter and stomped on the pedals (nav failure, don't ask) and this caused the chain to go so crooked while trying to do all the shifting at once it must've pulled the RD into a position it didn't know how to move from. A little bit of force on it and it kind of let go and was then fine again.

Says it looks like crash mode but it won't seem to come out of it

Crash protection isn't an electronic "mode" but a spring loaded breakaway connection between the cage and the servo. When the connection is released you should be able to push the cage sideways easily (with the back wheel off). When it lines back up with the slot on the motor shaft it'll drop back in and be stiff again.

If the cage doesn't move freely it's not crash protection.

The cage moves when pushed. Maybe the mechanic needed to push it further up the cassette as he probably only did it half way. I'll check a bit later when I go get it

It's all a bit odd. Went to get the bike back and was told by the senior mechanic that the mech was broken and he had no idea how to fix it. Gave me a quote to sort it (including new cassette and chain) totalling around 400 euros (parts at Shimano RRP).

Got it home and was going to swap the mech from my other bike to confirm it wasn't the shifter or something like that but decided to see what did work. Turns out it needed a bit of microadjust and it was fine again. I can only assume it was something like the B-screw and he'd refitted the mech after giving up on it as usually he doesn't engage in rip off tactics (insomuch as he doesn't set their eye watering parts prices).

So yeah... no definitive answer but I have a functional bike again.

Sounds like what happened to mine before TCR. Glad it's sorted.

I think mine was due to the shadow derailler mount. It's unsprung so my assumption is I tightened it all up like I would an older style derailler but because I'd not held it back I'd tightened it down when it was in the wrong position or only just on the b-screw lip and after the first shift it slipped and couldn't move. Once I removed it and refitted very slowly and carefully all was well.

@danstuff thanks for taking the time to share the photos.

I asked SBC to route the cables the same way and they did a great job. They said the BB area was "tight" so again, thanks for the advice to keep it 24mm Shimano.

They also used heatshrink tubing to keep the cables together.

2 Attachments

rusty stem bolts?!