nickc3

Hi, so I've just started messing around with adjusting my gears myself. Well, I switched wheelsets and this forced me to do it as its was not shifting correctly. However, no matter what I did., it could not get the granny gear to shift correctly without impacting other gears. What happens is, I shift into granny gear, and after a few revolutions, it jumps into next gear.

I gave up and switched to my original wheelset. I'm pretty sure it worked fine before I adjusted. But now, the same issue is with the wheelset. If I adjust so granny gear works, then the highest few gears are noisy and jump (big ring up front, smallest few in rear).

Is it possible I need to mess around with the limit screws? Or should I Just keep tweaking? Is there a recommended youtube or other instructinal on how to do this. I was exctied that I didn't need LBS for this..but maybe I do?

THANK YOU FOR YOUR HELP

Marcus_Ti

This sounds like Gear Position Control is turned on. It prevents cross-chaining. It is supposed to, unless you turn it off within e-tube

Setup your indexing per the Shimano DM materials

TimothyH

The first place to start with any Shimano repair or adjustment is dealer manual for your hardware at the Shimano technical documentation website.

https://si.shimano.com.

Find your model, download the dealer manual (DM) and do exactly what it says.

The dealer manuals are very comprehensive and if you follow it carefully and nothing is broken then everything should work fine.

I have the DM downloaded to my phone so that I can look at it in the garage.


-Tim-

jadocs

It’s obviously something your doing wrong since it now has the same problem with the original wheels. I also recommend downloading the dealer manual referenced above. You probably need to start from scratch.

nickc3

my message was a bit unclear. this isn't for cross chainring. this occurs in small ring up front, granny gear outback.

trailflow1

That sounds the like the low limit screw is too tight. If so, the RD will detect it and auto jump to the next cog to protect the motor.

Also check the B-screw adjustment and the top jockey wheel is not too close to the cassette.

The L and H limits screws have to be dialed in near perfect at both ends. Yes you'll need to adjust them correctly. Then if needed, you can do further tuning with the micro adjustment mode, by using the buttons at the shifters to incrementally move the RD to eliminate any chain chatter, but sometimes this step is not needed.

Read the manual properly, watch as many Di2 video's as you can

NoWhammies

I don't have any advice for you. I know, I know...

But, I have found this website to be a good wealth of information: https://di2center.com/

Hope it helps.

TerryDi2C

Thanks for the support, NoWhammies.
I'm adding new content or details to existing content all the time, but if there's anything you're missing let me know and I'll try to get some answers online ASAP*.

*ASAP means soon-but-not-too-soon-because-I-have-a-day-job-and-kid-too-so-time-is-limited ;-).

Wilfred Laurier

Sounds to me like it could be caused by a misaligned derailleur hanger - Di2 still bolts to the frame in the same way as mechanical derailleurs, right?

RoCou

Yes. Standard installation on the hanger, hanger alignment is the same - unscrew the RD mounting bolt (5mm Allen), place alignment gauge in its place (Park DAG is the classical one), align, remove alignment gauge, re-install RD, making sure the RD sits correctly on the stop notch of the hanger. Failing to do the latter can affect shifting performance (equivalent of mis-adjsuted B-screw).

RoCou

The shop manual procedure is the other way around - adjust the deraileur offset (done in 5th cog, going to adjust mode, fine-tuning offset), then (and only then) do you dial in the limits. They have to be actually further off than on a mechanical setup, to allow the motor to over-shift. The small cog adjustment, for example, is to hit the derailleur, and then give one turn extra space. If you tune directly to the required position (as you would on a mechanical), the motor won't be able to over-shift and may then drop you to the next gear.

TerryDi2C

Yeah, first do the fine tuing and then the limit screws. The Shimano 6870 manual page mentions this on pages 64/67 (not allowed to post urls yet, but the file is right here: si.shimano.com/pdfs/dm/DM-UL0001-03-ENG.pdf)

I also made this mistake and wrote something like "first set up adjustment bolts and then do micro-adjustments".. but that's correct for the front-derailleur only. For rear derailleurs, first do adjustment/fine-tuning and then set the bolts