So I totally messed up and nicked the wire coming out of my bar end shifter. It is DA Di2 original 7900. Do I have to replace the shifter or will I be able to find someone to make a splice and repair?
Thanks for any help,
Mike
It depends. If you nicked it and somehow shorted it out, you may have to replace the shifter. That seems unlikely, but I had it happen. I had to splice all kinds of Di2 leads to route the Di2 internally on my 2010 P3C. If you are reasonably handy, you should be able cut the wire, strip the ends, solder the connection together and then use heat shrink tubing to cover up the junction. The shrink tubing is critical though, as otherwise water (or another lose wire) can short everything out. Also, remember to slide your unshrunk tube over the wire and away from the splice before you solder. After the solder cools, you can slide it over the junction and shrink it up. Don’t get it too hot, as you can melt the insulation on the original Di2 wire.
Not entirely relevant to the topic, but you seen knowledgeable about Di2, so what the heck :-).
Is it possible to safely disconnect FD and RD connectors using some tool/thing other than the original Shimano tool?
And why can’t the internal wiring set be used externally, providing it’s long enough? They don’t look too dissimilar in photos.
Thanks!
I know a bit about wiring, not as much about all of the nuances of Di2. From what I gather, Shimano advises against removing the connectors without their tool, but I’ve never found anywhere that explains exactly why. I would imagine there are two possibilities - 1) people pull on the wiring, not the connector itself, which could result in pulling the wires out of the connector, and/or 2) the connector is designed to “lock” into the FD and RD to allow connection without allowing in water or elements and the tool is supposed to prolong the life of whatever mechanism “locks” the connection in place. That said, I’ve seen people say that as long as you grab the connector and not the wire, it’s very possible to remove the connector and reattach without any issues. If it were me, the tool is about $5 (http://www.amazon.com/Shimano-TL-EW02-E-Tube-Plug-Tool/dp/B00884323M) and I’d rather not take the chance as replacing the wiring harness is a royal PITA and the FD and RD are very expensive.
I’m not as familiar with the differences between the internal and external wiring harnesses. I know that the internal harnesses come with zip ties already attached. These are designed to push the wire again the tube to prevent the wires from bouncing around inside the tube and making strange sounds and/or to prevent excess wire from falling down to the bottom of the tube. If you wanted to use the internal wiring externally, I would think the difficulties would be that the internal harness may be a bit shorter and that you’d need to cut the ties off. I’m not aware of any differences in the quality of the insulation or differences in design, and I doubt there’d be many, but as I said, my knowledge of Di2 is largely experiential in having put the stuff in my bike. Others may have more info. Good luck.
Alright, from what I’ve seen from some close-up photos, one plug has two little pins, while the other has two holes that the pins slot into.
I guess what the tool does is simply press these pins in to release the connector and of course it prevents the wire itself being from pulled out of the connector.
Likewise, I’ve been looking some more into wiring. External wiring has the bottom bracket distribution block, while internal wiring has an X-shaped cable splitter.
It should be perfectly possible to use internal wiring externally, it’s just that things would be a little messy under the lower tube.
Now I need to know if there’s anything special going on with the wires themselves or can they be cut, elongated etc. Would you perhaps know that?
Thanks, Nikica.
You can elongate the wire, but it is a bit of a chore. Depending on which wire you are cutting, there are either 4 or 5 leads, and you will need to cut, solder and shrink tube, before then shrink tubing the whole housing back togther. There appears to be a good dicussion of this (with pics) here: http://forums.cervelo.com/forums/t/7054.aspx and here:
http://forum.slowtwitch.com/cgi-bin/gforum.cgi?post=2924491.
Thanks for the links. Just like I thought - they are only wires, not optic fibre :-).
Funnily enough, the guy with the Cervelo has actually used external wiring internally, haha.