Forum member 'exxxviii' did a good write up here:

https://forum.slowtwitch.com/...e_Write-Up_P6572184/

Though his is a little different from how I did mine in that he used two junction boxes up top, including one of the versions that sits in the end of one of the extensions.

For me, I used one junction box up top - the 5 port version - SM-EW90-B. So my brake levers and bar end shifters, so 4 wires, plug into that, then a 5th wire goes from the box, down the downtube to junction box SM-JC41 (4 port) which sits in the bottom bracket. The other three ports in that junction, one is used for a wire to the FD, one for a wire to the RD, and one for a wire up through the seat tube to the battery which you should have secured into your seat post.
You will charge the system using a charge port on the 5 port SM-EW90-B junction box (remember to buy charger, listed in exxxviii's parts list I think).
And, as per his write up, yes, you will need etube cables. I can't remember if the bar end shifters come with them already, but I don't think the brake levers do. So you'd likely need:
- 2 for brake levers to 5 port junction
- 1 to go from 5 port junction down to 4 port junction at BB
- 1 to go from 4 port junction to FD
- 1 to go from 4 port junction to RD
- 1 to go from 4 port junction to battery

I think he has those listed in his parts........sorry, early morning, headache, first coffee, rambling...

My TT fame is nearly 8 years old now but I have decided to keep it and upgrade some bits rather than invest in the 'latest' - which isn't really going to make me any quicker.

I have been looking for a Di2 TT groupsets but they just don't seem to exist. You seem to have to buy everything separately for the TT set up where the road set up has lots of choices for groupsets. Really quite annoying!!

If you google Di2 TT set up and go to the images page you will find lots of diagrams of Di2 setups in schematic format. Really helpful and helped me get my list of bits together. I am using the 5 port junction box as described by the poser above.

Again - another rant after coffee! Hope that helps!

---

He who understands the WHY, will understand the HOW.

If you don’t know where to start .... then it is simple IMO you enlist professional help by visiting the experts at your LBS - that is what they are there for and it is where they add value. Buying the parts yourself and doing the work yourself will not save you much cash and will be very time consuming with possibly a sub-par outcome.

Which frame, bars and stem?

I agree with what you are saying. The LBS will have all the knowledge. For me doing the upgrade myself is more about leaning the skills and knowledge for myself and accepting that I will make mistakes along the way which might cost some extra money. But its part of the enjoyment and journey of getting to the finish line. Leaving my bike at the shop for a few weeks and picking it up with all the work done leaves me with no additional knowledge and missing out on the fun of wrenching on my own bike. Everybody's mileage will vary in this regard!

---

He who understands the WHY, will understand the HOW.

If you think your LBS will take weeks to make such an upgrade then maybe you should try another shop! A good shop will do this upgrade in 24 hrs.

Already some good advice in here. That write up someone linked to is saved in my bookmarks and I referred back to a ton of times while recently doing my first run at it.

IMO do a bunch of research and then you can understand the how and why of it all. A good place to start is DI2 Center. They have an explanation of all the parts and layouts of everything as well, even links to a couple sites for each piece. Once you get how it all goes together you can make the call on the best routing for your bike, internal vs external junction A's, if you want a wireless sensor in there or not, pretty much everything about it. Shimano has their DI2 install manual available on their site and it's pretty simple to follow along for the most part. The routing is more of a bike specific setup but people have got super creative with what they can do as the wires are pretty easy to work with.

You can by complete group sets. You can buy just the ‘’upgrade kit” or a full kit that comes with cassettes, crank, etc. Several websites sell the kits. I dealt with Mybikeshop.com and they were extremely helpful in making sure I had the right stuff. You do have to measure your bike for wire length.

It’s not so complicated and can be done DIY. Several YouTube videos exist as well as the write ups mentioned here. However, if you’re like me LBS would likely do better mechanical work. I bought the Ultegra groupset ‘Upgrade kit’ and LBS installed. Note: I was the first Di2 install they’d ever done!! But they LOVED it and did it perfectly. Took about a week.

E-tube is pretty awesome in my opinion.

The website that jond81 suggested is great. I'm upgrading my 10 speed di2 to 11 speed and that is where I got most of my information together with the help of some people here.
I don't know where chgrubb lives, but I called all the local shops in my area to see if they had any di2 parts in stock and none of them had it. I even told one of them all the parts I needed to get a estimated cost when I called Wed and I'm still waiting to hear back. The one shop that gave me prices, for the most parts they were 30% higher than what I could get online for other not as bad, so I will order some parts from them, but mostly online shopping.

One thing to keep in mind. I only have the bar end shifters on my TT bike. First I had this setup because initially there were not stand alone buttons, just the ones at the breaks and my bar has integrated breaks. But I have not upgrade since the buttons came out because I really don't see the need. Di2 shifts very quickly and I can shift multiple cogs without any problem. I can move my hand form bar to the shifters and back very quickly if I'm not in the aerobars, which is not that often.

---

Tiago
---------------------
Sponsors: : Blueseventy :

That's the right attitude!

If you can re-cable a bike and hook up a home theater system, you got this.

Pushing Di2 cables through a frame is easy once you make this DIY Di2 cable guide.

I worried too much about where/how the battery would mount, but simply dropping it down in the seat tube (wrapped in bubble wrap) seems to work just fine. I even taped a short length of cable to it so I can pull it out when needed.

I held off on Di2 until last year, but now I appreciate how easy it is to work on!

This.

Nice! I had not seen this before - I will definitely try this when I build my next bike in a month ;-)

---

BetterShifting.com - Di2 help and guides| BetterShifting Instagram | Terry's Instagram

It works like a charm, and just as effective as the $70 park tool equivalent!

I've used both, I have to admit I preferred the park set, the magnets were helpful. But yes, its a lot to pay.