Would it be save to drill a hole in the stem (Syntace F119 or Ritchey 4 Axis) to put the wires through it for the junctionbox (I would like this to drop in my front fork, it is open (Canyon))?

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Canyon CF DA Di2 2010, LW III, 5,95kg
Canyon Aeroad DA Di2 2012, Mavic CCU, P2M Rotor 3D, 6,8kg
Grand Canyon CF DA Di2 2012, 9,5kg
Canyon Speedmax DA Di2 2010, Zipp 606

I used to drill stems for cyclocross (for the front brake cable) and never had problems. That was fairly common just a few years ago, so a very small hole on the bottom of the stem, a slightly larger one (for a stepped housing end) on the top.

Those were slightly heavier stems though, so I'm not sure how well that would work with a lighter stem like Ritchey WCS (I've never seen that Syntace stem live, so can't comment on it).

I suppose it depends on how many holes, how big they are, and where they are.

Probably, but unless you are an experienced engineer I'd get someone else to do it for you.

I had a stem modified to fit around my Lefty by the guys at Black Cat Bone Bikes. It's hard to explain, and I don't have it here to take a photo for you, but essentially they cut away a a fairly large section of it. I provided the concept and they did the execution.

They recommended I use a Thompson stem, due to both the alloy it's made of and the general beefiness of it. I've used it in a few races, including a 24 hour, with no problems. XC only, obviously.

If that can be done I imagine that your idea should be possible.

I drilled out my stem to put my custom Di2 head unit in it. I was going to use a Ritchey stem, but my head unit wouldn't fit in it, but it fits in the 3T one! If it fit in a Ritchey WCS that's what I would have used though.

I have been using this for about a year I think. No problems at all and lots of sprinting out of the saddle. Before I did it I consulted with one of the head engineers at Cervelo (I am a structural engineer) to get his take on it. We both felt that drilling a carbon stem was a bad idea, but that an alloy one would be OK because before you got close to a failure, you would see stress cracks develop on the stem. I check it regularly, but it still looks perfect. The holes in my stem are 1/4" diameter.

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Have you ever wondered if there was more to life, other than being really, really, ridiculously good looking?

@ Pritch...

Mate if you wanna clean up the front brake, check out the Omega brake on Tririg.. it has a cable hanger on the top of it.
gets rid of the ned fo the cable hanger spacer under your Stem if yo fussed..