Electronic & Hydraulic Shifting (Di2, Ui2, customisations)

Hmm. If I replace, any recommended alternative chainrings for a Rotor?

Anyone had an issue with a Di2 rear mech not being able to get all the gears it should? @Cycliste stacked it on Sunday's club ride, and while her bike was lying on the ground another rider rode over the rear wheel. The rear mech has obviously taken this rather badly, as it now only has 5 working gear positions. It's almost as if it thinks it's in the highest gear position (smallest cog on the cassette) when it's physically halfway through its travel,and then gets stuck when it gets to position 5 because it's up against the bump stop.

Any advice? Other than buy a new rear mech, which is my current plan.

http://blog.artscyclery.com/road/ask-a-mechanic-shimano-di2-crash-recovery-mode/

Definitely not that. If it was in crash mode it wouldn't move at all. I've put it into crash recovery mode anyway, and it cycles through the five available gears and then makes a ticking noise for a while as it tries to move up the cassette (which isn't there, because the rear wheel's a bit pringled).

Could a bent derailleur hanger cause it plough into the cassette - Does it index through 11 steps if taken off the bike?

Nope. I've managed to make it go to six by backing the adjuster screws right off, but then it hits the buffers and won't shift further. The real problem seems to be that when it thinks it's in the correct position for the smallest cog on the cassette, it's actually about halfway through the cassette.

Have you recycled the power buffers?

Are you just suggesting he turns it off and on again? A career in IT support beckons.

It fixes 70% of all problems.

FACT.

Yep. Took the battery out, gave it a nice long charge, put it back in again. No change. We appear to be in 30% territory.

Tap it a few times and blow on it.

There be dragons.

Might be worth hooking up to the di2 diagnostics whatsit(PCE1)

Clover

What are Clover rings? Mine were called "praxis works Road Compact Chainring Set 110mm - Black2Tone"

I something loose or flexing? I guess you've checked that the chainrings aren't moving side-to-side while riding?

Hit it with a hammer in the opposite direction of the prevailing wind.

Thats what they call them
https://www.praxiscycles.com/product/road-clover-rings/

their newest ones are called Buzz

https://www.praxiscycles.com/product/buzz-road-rings/

Here's someone talking about the crap shifting for 12 minutes. Strange shifting illustrated from 8:15

https://www.youtube.com/watch?v=MkEB8PDRE6U

Mine are definitely the clover ones.

Yep, that's my plan for this evening's entertainment. After I've seen whether or not the rear wheel can be saved or if it needs a new rim.

I've always got on very well with Rotor NoQ chainrings on Di2 setups. I've also had quite a few problems with Praxis rings on Di2 setups, although they seem fine with mechanical shift systems.

Cheers @danstuff

Osymetric rings work very nicely....

I also ran stronglight CT2 with DADi2 for a while faultlessly

If you're interested I have a pair with about 100km on them I'd happily clear out of the parts box.

Finally got round to connecting the rear mech up to the PCE1. According to the E-Tube Project software there 'may be a problem' with the rear mech. I think this is something of an understatement. When the PCE1 claims the rear mech is in the right position for the smallest cog on the cassette, it's actually on the third largest. I don't think I can fix that using the trim settings. Anyone got a spare RD-6770 they don't want any more?

Osymetric scare me with science. PM'd about the CT2's