ducati hyp

Hi, I have the Ultegra Di2 and love it, and love the FD auto trim BUT when it's on the small chain ring of the front sprockets and the fifth cog (from the biggest) on the rear I get some chain rub. As soon as I go to the sixth cog the FD will auto trim and all is fine.
It's not a big deal but was wondering if the FD can be adjusted and how??? I don't see any instructions for the FD, I do know how to adjust the rear and have but no info on the front.. Anybody play around with the FD ????

hueyhoolihan

bug in the software. just a WAG.

ducati hyp

WHATS >just a WAG mean ??
Are you saying it needs to be reprogrammed? It does have limit screws (low and high ) according to a shimano pdf.

njkayaker

WAG = "wild assed guess".

merlinextraligh

I don't know much about adjusting di2, but I'm 99 % certain tha the limit screws are not your answer. Do not mess with them for this purpose. Bad stuff can happen.

ducati hyp

I'm not going to play with limit screw. I am going to call Shimano as I don't trust LBS, because when I was there today to buy tubes they thought it was a limit screw fix . I want to know what shimano has to say .
I was trying to see if any others had the same problem and what the fix was.. Plus getting more insight before talking to shimano is a good idea . Thank for your replies and keep them coming. I don't think I will be able to talk to them till Tuesday.

Nerull

Does it still rub as you shift to larger cogs? If so, it could be a limit screw issue, preventing the FD from trimming far enough inward.

Park Tool covers adjustment here: https://www.parktool.com/blog/repair-...installation-1

metalheart44

have you tried the adjustment process that Shimano describes in its tech manual? It sounds as if that might take care of your problem or at least eliminate that as a source of the problem .... see pages 33-34 in the below doc

https://techdocs.shimano.com/media/te...9830778132.pdf

pa: the adjustment described in the parktool site posted by Nerull is a good representation of what is in the tech manual, wiith better graphics, especially figures 30-32

lazerzxr

The chances are you have too much clearence when in the spall ring and biggest cog.
This can easily be adjusted

hueyhoolihan

a WAG is a wild a$$ed guess. and i wasn't very serious. it's just what every service type guy likes to say when anything involves a piece of software. in order to avoid, what they believe to be, wasted effort, i guess.

but yes, i imagine there's a chip or two in there somewhere making some quick decisions from time to time. and it thinks it knows something about the spacing of the cassette and where the front chainring is relation to it. among other things...

edit: and i wouldn't be surprised if that stuff isn't configured by someone for the number of cogs, the number of teeth on each cog and similar info for the chainrings. maybe even the chainstay length. it would all figure into the quality of the shifting.

Nerull

If your knowledge of Di2 and how it works is 'zero' perhaps you shouldn't be giving advice on setting it up?

hueyhoolihan

i think this is completely accurate. but are you sure you've responded to the right poster? i don't claim zero knowledge, nor did i offer advice on how to set it up. check again. i think you meant to respond to somebody else.

roadwarrior

You probably need to reboot your bike. Control-alt-delete should do it.

I was on a plane a couple of weeks ago that had to be rebooted. Pilot comes on and says that we will experience a slight delay as he needed to reboot the plane.

tomng1989

Don't know if it's relevant, but what cassette and chainring combo are you using? I'm using a 12-25 and standard 53/39 chainrings and don't have a problem with chain rub in any of the gears.

mconlonx

Low limit screw and/or the attitude/angle of the FD. Also check height of the FD against the large chainring.

Wouldn't hurt to find a Shimano authorized Di2 shop and bring it there for setup/service if you don't trust the shop where you bought the bike.

hamsey

I have something similar going on but with DA Di2. Small ring up front and 4 cog in the back and I get rub. Had the same issue with SRAM Force. Starts on the 4th cog in the back. 50/34 and 11/27. Might try a different LBS and see if they can get it worked out.

BarracksSi

+1

After reading the Park Tool article, and comparing it to any mechanical FD I've adjusted, this would be my first thing to try, too.

I also like how the FD has a screw to adjust its rotation about the seat tube. I'd check that while I'm down there.

Nerull

No, i didn't. You're going on about software bugs and it needing to be configured for the right number of cogs and chainstay length, none of which is relevant to a simple FD adjustment. The imaginary version of Di2 in your head is irrelevant to problems setting up actual Di2.

hueyhoolihan

you might want to take a look at this. although i mentioned in my second post that my response was largely in jest, and admit i just looked this up, i wasn't too far off...

---------------------------------------------------------------------------

Another killer new feature is their diagnostic device. Dura-Ace has one, too, but it requires you to plug each component in separately and simply blinks lights to indicate a problem. This new one has a very, very nice GUI that loads on your PC (Mac version should be coming soon!) and only requires you to plug it into one shift lever to read the entire system:



The software and device is only intended to locate the damaged part, not diagnose what’s wrong with it. However…



…it does let you customize the way the shifters work. You can pick which button shifts up and down or even swap it so the left shifter/lever controls the rear derailleur. This is a great feature because the system comes set up to operate similarly to the mechanical versions in that the inside lever on the right moves to harder gear on the cassette but moves the front derailleur down to the small ring. I found myself getting them mixed up, and being able to make the same button on both sides control up shifts or down shifts is pretty cool.



Alas, the unit is really intended as a shop tool, and at $200 to $300 expected retail, it’s probably not something most cyclists will have laying around. If you’re loaded, though, it can make for some pretty cool bike geek party tricks. With it plugged into your system, you can tune the shifting and have it simultaneously show you where the derailleur is on screen and move the derailleur on the bike. It borders on creepy making something move just by tapping a button on your computer, but it’s pretty darn cool.

Speaking of adjustments, Ultegra has 30 steps for each gear (versus 24 for Dura-Ace Di2). You don’t need this tool to setup/tune your shifting, it can be done from the bike, too: Simply press and hold the button on the control module until it stays red, then press the shifter to make micro adjustments on one cog. Once you’ve got it lined up perfectly for one cog, it should be adjusted properly for all gears.
TECH NOTES



===========================================================

more at this site: https://www.bikerumor.com/2011/08/10/...o-tech-report/

mconlonx

You're still pretty far off...

hueyhoolihan

well!... that tears it. no soup for you! and you are OFF my christmas list.

mconlonx

*sob*

wkg

where did you get the idea that Di2 has "gobs" of software bugs?

why did you get involved giving advice about something that you don't understand and why don't you just stop before going any deeper?

hueyhoolihan

gobs of software. not bugs. read it again. i think you are reading what you want to hear. it happens all the time. nothing to apologize about...

Nerull

You didn't even look at them while posting, did you? The only thing you can configure in software is what the buttons do. That's it. There is no configuration for number of cogs. Or number of teeth. Or chainstay length. Or anything else you listed.

This is a FD tuning problem, and is solved like every other FD tuning problem has been since Di2 was a sketch on a napkin.