New frame ordered, going to fit Di2; a mixture of ultegra and XT

Will be using Ultegra Di2 shifters and bars not designed for Di2 internal cabling (to be fair, can't find any flared bars with the necessary holes)

has anyone drilled holes in bars near the shifter clamps to pass through Di2 cables

idea is.....
handlebar end plug port to shifter A thru bars
shifter A to shifter B thru bar
shifter B to junction box A

appreciate drilling holes is at my own risk; however, some locations will be less problematic than others
bars are alloy

the only place that would concern me drilling wise is near the clamp and even then one hole would not bother me- its just a wee hole and whilst i am sure an accurate machine could measure how weakened the bars are there the reality id for cycling use it will have no measurable impact

YMMV

It's likely to be quite a big hole as the plug has to go through as well as angling the hole so as not to have the sharp edge cut into the cables. Also deburring the hole could be difficult on the inside of the tube. Mrs PB has a Di2 bike with the junction box under the stem which seems a much neater solution and less death inducing.

Based on how metal fatigue and crack propagation happens I'd never do this. Alu drop bars flex quite a lot so drilling them really isn't a good idea. Lower/end part of the hooks, right near the end of the bar, maybe .. but certainly not near the hoods. Part of the problem is you'll tape them up and it's then hard to keep an eye on the potential crack forming - could take 3 weeks or 2 years, who knows. In that respect drilling near the stem is better

You can buy a Pro bar that has already done this by increasing the wall thickness as needed and creating/finishing the hole properly. Don't drill a bar for something as simple as a wire than can go under a run of tape or be sheathed by a protective tube if needed.

What is wrong with just wrapping the Di2 cable under the bar tape? The brake line is going that way anyway.

Just wrap the cables under the bar tape & get the bar-end plug junction box. You'd then only have to drill one hole for the junc box & It'd be near the bar end, its neater than the under stem type...

It works on Ritchey WCS VentureMax..

Plan on getting the bar-end-plug socket.

If only drilling one hole (for the bar-end-plug socket) cable to exit the bars then where do the shifters connect?

Bar-end-plug socket plugs into shifter A
Shifter A plugs into shifter B
Shifter B plugs into junction box "B" (in the seat tube)
Battery and rear mech plug into junction box "B"

If the cable connecting the two shifters together doesn't go through the bars (as some wiring has it) then does that wire pass along the top of the bar?

Other option is to run two cables (one from shifer A and another from shifter B) to the seat tube junction box, gives some redundancy should a cable be damaged
bring 1x both shifters will be mapped to do the same; quite like how can shift with either shifter.

hmm

Very good instructional video here https://www.youtube.com/watch?v=cON3w1IL_7k

There are a couple of configurations and some savage deburring to get the hole the right size but as the hole is not on a stress area cant see why it wouldn't work.

Photos please if you do it.

PS Thinking about it a thin slot rather than an oversized hole would be my choice.

I drilled my alu Boardman Team at the section whwre Boardman had done themselves on the internal dropper ready frames. Just above the BB on the downtube facing into the frames triangle (as far as I remmeber or was it under the BB)...

I know its not bars we are talking about but still...

I also drilled my carbon Canyon road bike in the head tube side for di2 cable to fit internally...

Anyway. For the alu Boardman I used to hear a slight creak which I never was totally convinced that it coudnlt be coming from the area around the hole I'd made but because of the way the forces work around the frame it never bothered me did that spot and I would inspect it regularly.

For the canyon carbon hole... I've been running for over 2 years without any bother (I strengthened slightly with epoky around the inside and outside of the hole)...

Regards your hole in alu bars... based on my exp and the fact that alu (if it were steel I wouldn't have any probs in driling the bars) is more brittle and less able to flex than steel. I wouldnt try that and either do the cablijg externally and under the bar tape or just get some bars that were internally drilled already...

I agree with jameso for what it's worth.

I wouldnt drill my own.

I wouldn’t personally. My face ain’t that pretty but id like to keep it mostly as is.


There may be ways to do it but there’s a very experienced bike designer and engineer on this thread both saying they wouldn’t. That seals it for me

Hmm

Thinking about it, don’t see any problem with a hole on the underside of the drop near the bar end; copy roughly where Pro Vibe place their Di2 cable exit hole

Will talk nicely with the mechanical engineers at work and have the hole cut at an angle on the CNC machine

Whilst neater, perhaps holes near the shifters are a step too far.
To be fair we’re all playing armchair engineers; however, will play it safe

Asposium wrote:To be fair we’re all playing armchair engineers; however, will play it safe

Not all of us

Easton do di2 flared bars, both EC70 and EC90 specs:

http://www.silverfish-uk.com/products/k ... -Handlebar

Scud wrote:Easton do di2 flared bars, both EC70 and EC90 specs:

http://www.silverfish-uk.com/products/k ... -Handlebar

neither have a hole near the shifter.

thinking a change of plan anyway
fit the 5-port junction box under the stem
then runs direc connection wires from there; single wire direct to rear mech, battery, and each shifter
makes a "field re-wire" far easier if should ever be necessary as no junction box in the seat tube

next problem is the lack of availability of ultegra di2 disc brake shifters, and dura ace seems a bit of an overkill

If you want to oook at some savings. A Linderets Tanpan will allow Shimano 11 speed cable road shifter work perfectly with 11speed Mtb rear mech.

I have this setup working perfectly on my cutthroat (and used the same group set in another bike previously)

A ‘bodge’ I stopped but it works perfectly.

My tourer had the bars drilled by someone for internal brake cables both under the hoods and by the stem. Must have been like that for 10/20/30 years without failing. Having said that I'd not be keen on doing it myself!