You will need either a display unit or a Junction A somewhere inline. Right now that means the 3 port, 5 port model or the external SM-EW67A (this works only with the external battery setup you are using). The EW67A is the easiest to stash and probably comes at the lowest price, but it has e-tube male wires and is intended to plug into female e-tube brifter ports. I think you Alfine shifter also has a male e-tube wire. So to connect you'd have to use a JC41 Junction B or solder them together.

Depending on what you need for gearing, with the 1 x 11 you should also be able to run the XTR Di2 RD.

Very useful, thanks.

So I can plump for either the 3-port JC41, or the EW67A. Why would someone choose one over the other; is it simply due to size?

This is the shifter I have:


It has no male wire off it. I think I've read that it's essentially the same as an Ultegra 6770 brifter. If so, I guess I shouldn't have problem connecting straight to the EW67A.

I've got a 11-32t cassette. I'd never thought about the XTR rear mech; very interesting. What's the compromise of using the XTR rear mech as opposed to the medium cage 6870 GS rear mech?

So glad you posted this; I'm wanting to do the exact same thing. Keep the thread updated with progress if you're willing!

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@floathammerholdon | @partners_in_tri

Sorry. For some reason I assumed you had a satellite type shifter in some kind of TT configuration. The Alfine brifter you have should work with the EW67.

The standard reason for the newer 3 and 5 port Junction A's was because they support the internal battery and provide a charging/configuration port. The EW67 only works for the external battery which is removed for charging. To configure the system with the EW67 in use requires connecting to one of the extra brifter ports. A secondary reason for the EW67 is that it is definitely easier to tuck away.

No compromise on the XTR. It would allow you to use even larger rear cassette cogs. The XTR would probably see a lot more use if Shimano didn't have the firmware hard coded to require it be used only with an XTR FD. Since you would be running 1x, this wouldn't be an issue and may open up more gearing choices for you.

Here is Shimano's compatibility chart from the e-tube site. They don't show the ST705 shifter working with non-Alfine RD's or hubs. You may just have to test this as you already have the brifter.

Lots of info here: https://carltonbale.com/...ng-you-need-to-know/ There do appear to be some questions about Alfine compatibility.

Certainly will. We can compare notes.

Brilliant. Thanks.

So, the EW67:


It looks like it has 3 ports: the 2 cables run to the shifters (I'll obviously only be using one cable, leaving the other redundant), which leaves 1 port left over. I'll still need to connect my battery and RD to this single port? How do I do this without using a Junction B?

Would I be better off with the EW90-A:

Could I hook up my 3 nodes (shifter, battery and RD) directly to this, and avoid using a junction B?

You are right about the 3-port Junction A. It should work as proposed, as long as you plan for the mount location and wire lengths.

As you mention, you could also combine the EW67 with the small Junction B.

Just plan for where you want to access the Junction A for trimming RD shifting and monitoring the battery level.

With the external battery you have, I used the EW67 "upside down" and ran an e-tube wire from the female port to the shifter. The two male ends were connected to the battery and to the rear derailleur (needed to extend it with one of the small B-junction boxes). Works perfectly for the maximum in simplicity and minimum in cost.

FWIW I run the Ultegra GS rear derailleur with an 11-32 cassette.

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/kj

http://kjmcawesome.tumblr.com/

I think that's answered everything. Thanks guys.

One more question:

If running 11-32 x 50t can I get away with the short cage RD-6870?

Because I'm running only a single chainring, I don't need to worry about taking up chainslack, however will the short cage fit over the 32t cassette? Is there any difference in the actual body of the SS vs GS (obviously the cage is a different length, but I don't need the chainslack take up with a single chainring).

I haven't tried larger than a 28 on the short cage. I'm sure the short would handle 30t. Not sure on 32. If you size the chain for enough length and turn in the b-screw that may do it.

I do have mid cage on a couple of road bikes. I am traveling thru the weekend and can check the RD knuckles for differences on Tuesday. I can also swap a 32 wheel onto short cage on tri bike and see how it works without adjustment. This is DA short cage but should be functionally the same as DA.

Why not get the GS (unless you already have the short cage)? I have the GS and it runs an 11-32 with no adjustment. I have had varying degrees of success exceeding 28 teeth with standard cage derailleurs and it seems more dependent on the derailleur hanger placement on the bike than anything else.

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/kj

http://kjmcawesome.tumblr.com/

Just curious what you mean...except for an offroad build, why would anybody buying the XTR derailleur for range of gearing need/want to run a front derailleur as well? It's literally the most expensive groupset component I have on any of my bikes that isn't a power meter, and I only have it in order to support a 1x 11-40 setup on a mtb.

Yeah, please; that would be very helpful.

I'm challenging myself to do this on a budget by sourcing used eBay parts; the SS is much easier to get hold of than the GS.

I'll give it a go with the SS and see how I get on.

That's fair. If it doesn't work, you may need to look at a 48 or 46 up front depending on what cassette you can make fit. I have been pleasantly surprised with how useful having 44x11 is as a "big gear".

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/kj

http://kjmcawesome.tumblr.com/

Cross bike, gravel grinder, extreme climbing bike all in one is where I'd like it. Super low gearing, much less gap between gears than 1x and still top end road options. I only have 1x on my fatbike and wouldn't want it for varying use because the gear range has to be dialed using the front chainring choice.

Plenty of stupid expensive parts in tri and cycling worlds so that is just par for the course.

You seem to have a pretty good sense for these builds/components...working on a gravel setup myself and I have an XTR FD gen 1 available but I would like to get the new XT RD gen 2 to save on costs. Presumably these will work together, yes?

I would expect the 2x XTR FD to work with the new XT system. Shimano is promising that existing XTR Di2 owners will be able to "upgrade" their systems to the new XT systems with a control display and battery swap similar to what has been promised for the new DA Di2 system. Seems that the upgrade would only be necessary if you want the use of the new e-tube Bluetooth app.

My go to compatibility chart on the Shimano e-Tube site hasn't been updated to include the XT Di2 yet: compatibility chart

You'll probably have to just give it a try to verify it works.

Right because it is so difficult to connect to a computer the one time a year you need to upgrade the firmware ;)

Ok, my latest plan regarding wiring, is to use the EW67 in upside down orientation i.e. the 2 cables of the EW67 would go off to the battery and RD, while the female port would have a cable connected to take it up to the single shifter.

Now, obviously the 2 cables of the EW67 are far too short to reach the RD and battery. I know adding a Junction B, and another couple of cables would solve this, but I'm toying with the idea of instead splicing into the EW67 cables and just extending them. This would really simplify the whole wiring, and keep the cost down. It does of course rely on some good soldering skills, but in theory would this work?

So the upside-down EW67 is how I set up my external 1x11 bike. I placed the junction under the down-tube so one of the male wires was the correct distance from the battery. Bought the correct length wire to run up to the shifter. Ran the second male wire to a B-junction on the chain stay and a short e-tube wire to the rear derailleur. So yeah the B-junction and extra wire are like $20 each, but seems like a good $40 to spend.

For my current build (1x11 Emonda), everything is internal with a seatpost battery and 3-port junction under the stem. Rear der, battery, 3-port junction wires all meet at a B-junction stuffed into the bottom bracket and the shifter plugs into the junction box. It's actually less clean up front because I have an ugly junction box on the handlebars and 2 wires up front instead of just one.

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/kj

http://kjmcawesome.tumblr.com/

Should work fine. The cables only have two small wires. I'd recommend getting some small diameter heat shrink with the interior glue option to use for the individually soldered wires and for sealing over the cable splices too. You just have to remember to have the appropriate diameters and lengths in place before completing the soldering work!