Help with re-sheathing Di2 E-tube wire and/or drilling or expanding hole in Ti frame

[echappist]

I have a titanium bike I'd like to retrofit in order to run Di2 internally through the down tube. There's a screw holding a badge to headtube via a 1.5 mm allen key, which makes me think that the diameter of the hole is perhaps 2.0 mm. This hole is definitely too small to pass through the plugs of a etube wire, but it's only a little bit smaller than the body of the Di2 wire.

My original hope was that I could cut an etube wire in half, thread one of the halves through the hole, and then solder the two halves back together and seal the wire with shrink wrap, but this currently won't work without some modifications to either the frame or the wire.

So I'm left with two options: either expand the hole in the headtube or drill a new hole somewhere, or re-sheath an entire Di2 cable in order to reduce its diameter (the two wires within the original sheathing fit through hole in the headtube). Thoughts on feasibility of either option? Also, if you know of someone who could do either on the East Coast, that'd be greatly appreciated (I know Ticycles does it out in Oregon, but the shipping alone may be $90)

Many thanks in advance!

[Look585]

Don't overthink this. Get a decent quality 6mm drill bit and have at it. Use a bit of chain lube as cutting oil.

While you're at it, drill a port in the seattube for the FD wire as well.

Use the 6mm round Di2 wire plugs for a nice finish.

[Kontact]

Trace your headbadge onto the frame, then remove the badge.

In a convenient spot, drill a hole just big enough for the cables (not plug) outside the traced outline.

Now drill a plug size hole touching the first, but just inside the traced outline. Use a file as necessary to connect them.

Run your plug through the larger hole. When everything is hooked up and working, push the cable over onto the small hole side. Replace the headbadge, which will cover the larger plug hole.


Hope that makes sense. You'll end up with it looking like your cable disappears under the headbadge.

[oldpotatoe]

Originally Posted by Look585

Don't overthink this. Get a decent quality 6mm drill bit and have at it. Use a bit of chain lube as cutting oil.

While you're at it, drill a port in the seattube for the FD wire as well.

Use the 6mm round Di2 wire plugs for a nice finish.

I did the same to a Merckx MXL..and have talked to Butch at Moots about doing the same to Vamoots..and.........for the OP, which ti frame is it?

[echappist]

Thanks everyone for chiming in. I like what is proposed by Kontact but am a bit afraid that any drilling or enlarging might damage the bike. How would I know that what im doing is at a low stress area?

The bike is a Lynskey, which usually has its own QC issues...

[oldpotatoe]

Originally Posted by echappist

Thanks everyone for chiming in. I like what is proposed by Kontact but am a bit afraid that any drilling or enlarging might damage the bike. How would I know that what im doing is at a low stress area?

The bike is a Lynskey, which usually has its own QC issues...

I would drill a hole in down tube, by front der, back by rear der..6mm holes, size of connector. Altho a thick tube by comparison, headtube, I wouldn't drill a hole in there..remember clearance for the fork steerer..

[Look585]

I bought 2 R240s this spring during one of their sales.

This one I had drilled at the factory:

DT ~1-2 o'clock


ST front of tube on driveside below clamp


CS, in front of the housing stop on the bottom of the tube.


This one I drilled myself, I think it looks a bit cleaner:

HT next to the head badge


ST, same as factory drilling


R Rear dropout (saw this location on a Foundry with identical dropouts.

[echappist]

grazie mille for the pictures. Unfortunately i don't think i'm anywhere as capable when it comes to job like this, but it's good to know that it is possible, so at least I could describe this to someone. One thing that concerns me is that the top tube/down tube/heat tube junction area is usually considered high stress, and that was why i was somewhat uncertain about drilling there.

Nice bikes, btw!

[Look585]

It is way easier than you fear. The hardest thing was to make sure the drill bit doesn't "walk" when you start the hole. I got a "center spotting" bit to start the hole and then swapped to the 6mm standard bit.

Alternatively, you could do a starter hole and then ream it out to 6mm with a tapered reamer.

Center Spotting bits:


Tapered Reamer:

[zap]

ugh, titanium.

I would not recommend drilling holes in a ti frame. Do it wrong and a crack will form and propagate as fast as tearing paper. Merlin found this out in their early day's.

[apple]

I drilled a titanium frame for di2 from scratch, no issues whatsoever years later. Three holes total, one in the top tube, the seat tube, and the chain stay. I used this product called a gator v drill guide, basically a portable drill guide, and a titanium drill bit. Marked everything, put the drill guide on the frame, clamped it down hard in multiple places, and drilled. I drilled a hole slightly smaller than needed, then used a dremel with a metal sanding bit to smooth out the inside of the drilled holes and enlarge them just enough to get the di2 plugs in there. Looks totally factory, wouldn't hesitate to do it again.

[Kontact]

Originally Posted by echappist

grazie mille for the pictures. Unfortunately i don't think i'm anywhere as capable when it comes to job like this, but it's good to know that it is possible, so at least I could describe this to someone. One thing that concerns me is that the top tube/down tube/heat tube junction area is usually considered high stress, and that was why i was somewhat uncertain about drilling there.

Nice bikes, btw!

You'll note that all those holes are well away from welds when they are in the thin tubing.

[echappist]

Out of curiosity, how did you guys determine the "proper" place to drill and thus avoiding the weak spots or places experiencing strain?

[Kontact]

Originally Posted by echappist

Out of curiosity, how did you guys determine the "proper" place to drill and thus avoiding the weak spots or places experiencing strain?

Some parts like the head tube, BB shell and dropouts are thick enough to not matter much.

The areas of concern are the rest of the tubes because they have thin walls that are effected by stress risers and zones effected by weld heat.

Personally, I wouldn't be in a rush to drill holes in any frame, but if I had to I would look at where the manufacturer of your make and model does it with their Di2 ready frames.

I've noticed that most cracks on Ti frames start at welds or in the HAZ, and usually on the side of the tube rather than top or bottom. But that's just from what I've seen. However, the hole placement I've seen also seem to avoid those spots.

Also, keep the hole away from the front derailleur clamp.

[echappist]

thanks for clarifying. What is the HAZ, by the way?

My hope is that Shimano would come out with wireless Di2 as to render all this moot (not a fan of Sram eTap).