Last year I was fortunate enough to finally scrape together the funds for a Di2 groupset. Since it was initially launched I've loved the idea of clicking a button to shift, as opposed to the normal long lever throws required. I have to say, I miss a certain part of the tactility of a mechanical system. For example, when climbing under power being able to feel the tension build as you push the lever and the chain starts to shift and being able to ease off the power accordingly to allow it to move to the next gear. However, one of my biggest annoyances while riding a road bike with it's multitude of bar positions, is the need to let go of the bar when needing to shift, when climbing with hands on top of the bar or cruising/descending with your hands low down on the drops. As such, an upgrade to remote buttons was something I looked forward to. Except, the system Shimano offers just seems so badly executed to me. The climbing shifter is an ugly monstrosity that I simply could never attach to my bike. It's just too big. Heaven knows why. Some say it needs a circuit board in the enclosure. That's bollocks. The sprinter buttons on the other hand make more sense, but seeing as I won't ever be engaged in a sprint, didn't really offer a good solution either. I thought of buying them and extending the cables, but the cost of R1700+ seemed like too much. Thus I started doing some research to see if anyone had DIY'd a system. I found a link to a setup that used 2x micro switches http://benmanson.com/review/di2/di2buttons.htm This involved still acquiring a Shimano cable extension with their unique 4-point plug, at over R1000 for the cable. Again, the cost seemed silly, but at least this proved that the circuit board in the climbing shifter was not needed. Further research on one of the road bike forums revealed that the different looking plugs on the sprint shifters were rumoured to be an attempt by Shimano to make users believe that that was the only solution. However, several users reported that the standard Di2 electrical wire and plugs would work. The idea of using the sprinter ports and having a button either side of the bar/stem also appealed to me more than using the climbing button port. Using the climbing port meant both buttons would be on the same side. Also, I wanted buttons below the drops as well and I felt 2 buttons mounted on one side would be too bulky. I decided to order a 1m cable from CWC and upon receiving it cut it in half, stripped of the ends, plugged it in to the sprinter port and found the system shifted when the 2 wire ends touched. Voila. I then ordered some IP67 rated micro tactile switches from RS Online http://za.rs-online.com/web/p/tactile-switches/7931664/ It was a pretty simple process, even though I'd never soldered anything before in my life. Below a few pics depicting the process: The completed 'wiring loom'. Sorry the pic is out of focus, but I only realised this after completion Soldered button I applied a glob of silicone to the buttons, allowed it to dry and then trimmed it. The buttons are dust and splash proof, but obviously water would still cause a short between the two wires. I taped the wire and button to the bar as you would normal cables and wires Below the drops, I used some double-sided tape to lessen the transition between the bar and the button. Like I said, hack job. I enlarged one of the holes on the bartape to accommodate the buttons. And the finished product
