I think you're in a pickle trying to get the cables out the back of the stem cover then immediately turned 90 degrees down into the port in the frame.
As a possible solution I'm envisaging an inline pulley arrangement behind the stem, something like an Avid rollamajig, Problem Solver Travel Agent, etc, but looping up and over through 270 degrees not 90 degrees.
At the front end, maybe a sleeve of heatshrink would be neater than electrical tape? Exit the cable at about the extension clamp and it should have enough bend to tuck under the stem cover. Either that or slot a hole in your extensions, if you dare...
(I would imagine the aero penalty of doing this would probably be more than just the bare cables as they are now...)

I've never dealt with hydraulic bike brakes but I don't understand why noone uses hydraulic tube fittings to just make an instant 90 degree bend. Such as: https://www.mcmaster.com/51115k554 (I make no guarantees about this part or its suitability, it's just there for an example)


Or upgrade to Di2 (sort of pink)

Funny you bring up Di2. I’m actually considering eTAP purely for the aesthetics.

How wrong is that?

Scott

eTap for aesthetics and Di2 for performance ;-)

At the front end you can make Di2 cleaner looking then eTap/blip box

I'm reading up on electronic shifting and see your point. Reliability is a must!

Walk me through the Di2 conversion. What components need to change?

For example, looks like I'd need to swap out my Magura brakes to utilize Shimano's brake based base-bar shifters.

How about my Quarq Elsa and Dura Ace Chainrings? Are those components compatible with Di2?

What else should I think about?

Scott

I'm about to undergo a similar upgrade myself (P3, TriRig Aplha1 and Omega Brakes) , curious how yours turned out.

How did you route your rear brake cable? It looks like you ran it through the frame, bypassing that little notch on the Non-Drive-Side? It looks really clean!

Did you run into any other issues with this build?

Hey; sorry for the slow response. On the road this week.

I ended up going all in with Di2. If you think the pic above is clean, you’ll love the final look. I can post some pics when I get back home.

There were some hiccups along the way, but the final result is very clean. I recall getting the junction box into the stem cavity required some modification, and picking the right cables is an art form with a learning curve. I could dig up my notes on all that if you go that direction.

The bar itself is good, but not great. I never got quite as comfy as I was on my old Zipp Vuka, but that’s probably more about me than the bar. And it’s certainly a faster setup. So, more of a short course horse for me.

Nice! I am running DI2 also!

Would love to see pics of the finished rig, if you've got them handy! And/or any notes you have or recommendations you have, would be more than helpful!

I am going to try running Jagwire Road Pro for the brake cables (they just seem to be a quality option and seem to be pretty popular, but if you have a different recommendation, I'm all ears)

I'm hoping the bar will be an improvement over the original Vision basebar that the bike came with. If it's not comfy for me, it will at least be (I hope) a few watts of aero savings by cleaning up all the current cabling around the cockpit, and that is really what I am after....although I am going to be racing this in long course races...so I'm hoping I can make it as comfy as possible lol :D

I drilled a hole in the plastic box that's epoxied into the frame - the one that everything routes through, and was able to run the rear brake cable directly into the top tube. Everything looks much cleaner now. As pictured by the OP, I am guessing that his LBS routed the cable under the top tube, which does not require drilling, but makes for worse braking.....

---

Next races on the schedule: none at the moment

I'm think I have found myself at the point where I need to start drilling lol

Any tips for me while I bust out the Dremel?

I used a regular small drillbit, went super easy, aimed for roughly the mid point in that plastic box.... once the first drillbit got through, I ran a thin wire through and was able to see it get near the grommet by the seat post. Then I used a larger bit to enlarge the hole to be able to run housing through it. After a bit of drilling the housing was able to get through, though I also had to enlarge the opening in the grommet so that I could ran it all the way to the brake.

All in all, about 20 mins of work. In some cases, I heard that the box itself can dislodge and come out if epoxy was not done that well. In that case you will just have a much larger opening.

---

Next races on the schedule: none at the moment

Awesome! Thank you!

Fingers crossed lol

Yeah just did a similar thing. Got rid of the hydraulic brakes mainly because the levers exploded and I did not want to get a PhD to put them back together. Also I am not too sure I could have routed through the frame with hydaulic cable.

I did drill the plastic insert ( i think I used a file actually) and ran the rear brake cable to a tririg brake. I went etap which I do like but definitely keep and extra battery around.

Here is a schematic of my setup along with some pics of the final build. Rear brake cable (hydraulic) exits the stem and routes through the top tube.

Wow nice work! Very Clean!

I was able to route my rear brake through the top tube after everyone's help, so thank you! (And you weren't kidding, took me a few cable/housing configs to make it work smoothly)

How did you manage to fit your DI2 junction box in the stem cap compartment?? After brake cables were routed there was hardly any room in that little compartment

Yes, it’s a tight fit!

Based on input from others on this board, I used a dremel to file the junction box down until it fit. As I recall, there is a bit of extra casing on the box that can be filed away without consequence.

That worked! Filed down the part that is normally used for attaching to stem (or other places) and a little bit of the excess corners around the whole thing and that made it JUST small enough to squeeze in there. Still a pretty tight squeeze though.

Thanks for the help on this! Excited to take this thing out for a spin!

Nice! Time to work on the engine.