Readers’ Rides: Julian DaSilva Blends Di2 with Atomik Carbon for Niner RKT Green Machine, Creates 3D Printed Junction Mounts for Tri Bikes

Can we get some more details on the internal MTB Di2 wiring? I’m guessing he’s drilled holes in the bar and steer tube to make this… which sounds like an accident waiting to happen and the guarantee of absolutely no warranty support when it does. I don’t think light weight parts are designed to have random holes drilled in them.

The only hole that would bother me would be the one by the shifter. Most bars are thinner there and you have some leverage on it. Middle of the bar and steerer tubes can safely be drilled for a Di2 wire sized hole. Only thing that could cause an issue would be a hard crash; and thats not a warranty problem.

Some aero road bikes run the brake hoses or brake cables internal in the stem and down the frame. Brake hose inside rigid forks too. Way hard to this do this on a suspension fork, but I would like to see someone have a go at it.

“unlike SRAM Red eTap, Di2 still uses wires”

Yeah, but Di2 works on mountain bikes, and SRAM Red eTap doesn’t. I get that we are all stoked about wireless for the dirt, but knocking XTR Di2 for having wires is just a teensy bit premature. (Yes, we all know it’s coming, but wake me when I can buy it).

???

It depends, you have to take into consideration that the steerer tube inside the headtube does not experience any type of load that would cause some type of failure. Remember the steerer tube is supported by the headset bearing top and bottom, also a lot of stresses are down by the crown, thats why lower headset bearings are usually the first to go. My guess would be the steerer tube would break through the headtube before anything happened to the steerer tube because of the tiny hole drilled.

As for why Specialized did it there way, it’s simple mass production, ease of assembly. The creator of this bike said he had to do intricate work to route the wire, sounds like a expensive assembly.

I agree that Di2 on the MTB is well worth it. Zero maintenance, perfect shifts all the time, and you can fine-tune the adjustments way more than on mechanical XTR. I didn’t get the MTB display/3-port junction because I wanted a clean front end. I used the road 3-port junction, mounted on the seat tube between the rear shock and the linkage. Then I ran 1 long wire from the shifter to the BB internal junction box and used heat shrink around the wire and the rear brake hose. It looks really clean, like a SS except for the 1 shifter.

Cool Rider – If you’ve built a venge vias before you’d know that it would have been much much easier for Spec to simply drill holes in the steer tube. It’s a very complicated system they have created in order to have all the cables hidden, while not drilling holes in the steer tube.

I’ve been lucky enough to talk to some engineers at a major bike company and I asked them about drilling holes in the steer tube, specifically to run fully hidden Di2 wires (this was a few months ago). I was met with a quick and serious ‘NO, don’t do it!’. They said they where playing around with doing such a thing and it’s proving to be a lot harder then they thought.