How to solve absence of holes in frame for di2 cables for FD and RD

[fruitfly]

As the title suggests, I have a new frame that lacks holes for the di2 cables for front and rear derailleurs in the seat tube and seat stay.

The only kludge I can see is to use the drainage hole below the BB to bring the cables outside the frame, and then zip strap them to the seat tube and chain stay. Fugly, but it would work.

I could also switch from Shimano 9170 to SRAM wireless, although I prefer to use the same groupset for both bikes to make it easy to have spares, switch gear between bikes, swap wheels, and reduce the number of tools needed.

Any other thoughts?

Hugh

[Karvalo]

Are you angling for someone to tell you whether you can drill it or not?

If so what is it and what's it made of?

[tomtom]

Normally it's possible to use the hole(s) for the (disc)brakecable.

[Miller]

Are you angling for someone to tell you whether you can drill it or not?
If so what is it and what's it made of?

You can definitely drill it.
What is it and what's it made of?

[Butcher]

I have an older S-Works Tarmac frame and I was not concerned with drilling holes. I used a dremel and ground the holes verses a drill bit. Once drilled, I used a touch of epoxy on the inside diameter. Never had a problem with 8+ years now.

[Karvalo]

Normally it's possible to use the hole(s) for the (disc)brakecable.

Interesting theory. Are you then planning to run the wire through the wheel to the mech on the other side?

[StiffWeenies]

Carbon Dry Japan has a service where they drill holes for internal routing of rim brake cables and electronic shifting wires.

If you have an older EPS and want to further clean up your wiring, Drop Bar Concepts in NYC used to offer an EPS V3 external interface that was modified to fit into a bar end junction box solution similar to the EPS V4 internal interface. I remember one of the guys there saying that it was possible to do the mod on EPS V1 and V2 as well. For Shimano, I'm not sure if 7970 and 6770 10s Di2 can be used with the EW-RS910 bar end junction box.

[bremerradkurier]

Seems like slotted water bottle screws could be a possible solution.

[JMeinholdt]

I went through this with my wife's bike a while ago: viewtopic.php?f=3&t=162786&p=1598005#p1598005

Basically, I used the Di2 specific wire covers. I enlarged the drain hole from the bottom bracket ever so slightly so that I could use the seatpost battery mated to a bottom bracket junction box. It worked out well.

[fruitfly]

Thanks to all who replied. The maker has asked that I return the frame to his shop, and he will drill the holes.