Goatlink with 11-42 Ultegra Di2

[hairylegs]

I should preface this with the right move is prob to seek professional help but thought it'd be worth checking in with the wisdom here....

Backstory - I got an 11-36 for trail stuff and didn't refit the chain. Big to big caused problems. I *tried* to remember to not do that but ended up really jamming it - so much so that one of the plastic pulley gears fractured! Proud moment. I replaced it with an alloy one off Amazon.

I bought a Goatlink and SRAM 11-42. Installed them, along with a new Shimano 11 speed chain (yes, facing the right direction!) Funny, doing the technique of big-big without the pulleys was the chain uncut. So I'm technically 2 links short.

Last piece of useful info - I've got an Absolute Black elliptical small chainring. I also use a Wahoo Kickr Core with the old 11-36 cassette...and experience similar shifting issues.

I cannot get this bloody setup shifting smooth. I *think* I get it then I'll shift at some point and it doesn't go until I screw around with going back and forth etc. Pretty sure I've got the limit screws setup decently. And I've messed with the trim endlessly...

The B-screw is the big variable (I think.) It's in pretty far and Big-Big is ok. But shifting seems to improve the closer the derailleur gets to gears. Is this true? But when I do that (back it out) Big-Big is ugly grinding (not actually jamming, but close.) Further more, when I'm descending in Big-Small the chain often derails when I even slightly back pedal. (Scary!) It goes right back on, but there's not enough chain tension.

So...am I:

1) Just not tweaking it well enough to work
2) Are the aftermarket pulley gears contributing
3) Did I somehow damage my derailleur when I jammed it?
4) Would I be better off with a 11-40
5) Asking for too much cadence from this Renovo John Day

Any thoughts would be appreciated. I just wanna shift like a normal person! :)

[CiclistiCliff]

Get a normal cassette. Get smaller chainrings.

Your ‘custom’ set up that all those websites claim ‘works great’ is not at all functional.

And to answer your question, no, it wont work.

[jtbadge]

Did you mean to buy a RoadLink?

Your hanger is probably bent either way.

[dem]

Running things at the extreme will be a compromise some where, so fooling with these settings without consciously deciding those trade-offs will result in apparently random results (or exploding derailers :)

I am running a 6800 Di2 + Roadlink + Shimano XTR 11-40 cassette, with 50/34 compact.

1) You probably bent your RD, hanger, or both. Replace hanger, check frame alignment with hanger alignment tool, borrow or replace RD.

2) You really need to size for big-big, get a longer chain. If you don't have enough chain capacity, small-small may be floppy or barely any tension, but at least nothing explodes.

3) As you discovered, extreme "B" screw will cause the chain to skip gears when you pedal backwards. Set this as close as you can, but it can still happen (depending on chainstay length/angle/etc) so you just have to use care to not do that. The Roadlink helps with this, but not entirely.

4) If you're running the new "Shadow" Ultegra Di2, your top pulley is NOT the same as a road pulley, it has longer teeth. So if that is your combo, you have the wrong pulley.

Best of luck - I run all sorts of frankenstein drive trains because nobody sells the things I want to ride.

[Mark McM]

The Roadlink only increases the maximum sprocket size the derailleur can handle - it doesn't change the derailleur's capacity. A derailleur's capacity is the maximum sprocket and chainring size differential (i.e, the amount of extra chain the derailleur can wrap up). An Ultra Di2 GS derailleur only has a rated capacity of 37 teeth, and presuming that your chainring size differential is 12 teeth or more, with the 11-42 cassette you've exceeded the derailleur capacity by at least 5 teeth.

[NHAero]

I've been looking into this as well. I'm going to try the R8000 GS with an XT 11-40 11s cassette. If it doesn't work well, the next step is the latest Wolftooth offering, the Roadlink DM. I should add that the chainrings are probably 44-33 on one bike and 42-33 on the other, so total chain wrap is 40T and 38T. My experience is that I've never seen issues bumping Shimano's max wrap limits a tad. Dunno if 5T, as the OP mentions, is too much.

[hairylegs]

Thanks all! This is all great info and advice. I'm mistaken! I have the Roadlink DM! And my Ultegra is not the new RX...

I think my current plan is to downgrade to a standard cassette and see if I can get it working ok. The derailleur does look tweaked. The hanger itself is robust (looks ok) and I'm not even sure where to find a replacement since Renovo went under.

I'm thinking the RX derailleur and an 11-40 is in my future.

Will keep you posted. This B screw thing is really confusing!

Thanks again

[jtbadge]

You said you were running the AbsoluteBlack oval small ring, but ow many teeth are your chainrings? A different derailleur probably still won't be able to handle a gap more than 10-12 teeth in the front with that cassette.

[NHAero]

I have a 9 speed Shadow XT RD on one bike with an 11-40 10s Sunrace cassette and I reversed the B screw to move it back far enough to shift into the 40T cog. No Goatlinks or similar.

Thanks all! This is all great info and advice. I'm mistaken! I have the Roadlink DM! And my Ultegra is not the new RX...

I think my current plan is to downgrade to a standard cassette and see if I can get it working ok. The derailleur does look tweaked. The hanger itself is robust (looks ok) and I'm not even sure where to find a replacement since Renovo went under.

I'm thinking the RX derailleur and an 11-40 is in my future.

Will keep you posted. This B screw thing is really confusing!

Thanks again

[dem]

I've been looking into this as well. I'm going to try the R8000 GS with an XT 11-40 11s cassette. If it doesn't work well, the next step is the latest Wolftooth offering, the Roadlink DM. I should add that the chainrings are probably 44-33 on one bike and 42-33 on the other, so total chain wrap is 40T and 38T. My experience is that I've never seen issues bumping Shimano's max wrap limits a tad. Dunno if 5T, as the OP mentions, is too much.

I have another bike (heh) that uses this combination - I suggest going straight to the Roadlink DM. Without it, you still have to crank the "B" in really far which makes it sub-optimal. When I redo it, I will add the Roadlink DM.

Also the chain capacity affects only the ability to absorb the slack in small-small. If you're willing to run that a bit loose, you can definitely push chain capacity.

[Look585]

I'm thinking the RX derailleur and an 11-40 is in my future.


Be careful with this. If you turn on the clutch in the Di2 RX/11-40, the system may not work due to too much cage tension. I couldn't get it sorted and gave up.

A smarter person (John H.) indicated that he moved the cage tension spring to the lower option and then was able to get the Di2 RX/11-40 combo to work in both clutched and unclutched settings. This will involve disassembling the cage and changing the tension spring position.

[NHAero]

Thank you for that experience.
My sense is that people who are doing this stuff are generally using the large ring most of the time and the small ring gets much less use (that's been the case since I set my Anderson up 12-34 and 44-33 in front, because the 44T ring gets me 40-100 gear-inches. So the 33t ring is using at most 6-7 of the 11 cogs, and small-small isn't a concern.
I do recognize that others may have quite different requirements and set-ups.

I have another bike (heh) that uses this combination - I suggest going straight to the Roadlink DM. Without it, you still have to crank the "B" in really far which makes it sub-optimal. When I redo it, I will add the Roadlink DM.

Also the chain capacity affects only the ability to absorb the slack in small-small. If you're willing to run that a bit loose, you can definitely push chain capacity.

[dem]

Be careful with this. If you turn on the clutch in the Di2 RX/11-40, the system may not work due to too much cage tension. I couldn't get it sorted and gave up.

A smarter person (John H.) indicated that he moved the cage tension spring to the lower option and then was able to get the Di2 RX/11-40 combo to work in both clutched and unclutched settings. This will involve disassembling the cage and changing the tension spring position.

So on ANOTHER bike (okay this is ridiculous) - I am running an XTR RD with the Tanpan travel agent adapter and a SRAM 10-42 cassette - and I had the same issue, I couldn't get it to shift into the tallest cog with the clutch turned on.

On the other hand, I've never had any dropped chain issues and this is my most abused off/on road rig.

and I think that concludes all combinations of my frankenstein drivetrains.. :)

[hairylegs]

So I took off the Road Link, put an 11-32 back on and I think the derailleur is bent a bit. Hard to tell...but the hanger could be slightly off as well. It's like almost 1cm thick though so hard to think it would bend.

Ordered the RX derailleur and hoping for the best! I might need to followup about adjusting that cage tension.

Thanks for all this...hoping I can get the 11-40 working. 42 was likely more than I needed anyway!