Page 1 of 1

Di2 wire lengths

Posted: Tue Jan 23, 2018 10:03 pm
by vinuneuro
Could someone kindly confirm if the wire lengths I have are correct? This is from a Specialized rep but they are not matching up with what I've found online. For a 56cm frame 2016 Diverge which is near identical dimensionally to the Roubaix.

Downtube 1000mm etube (seems 50mm long?)
FD - 500mm (seems 100mm long?)
Shifters 2x 350
RD 700 or 750 (seems 100-150mm long?)
Battery to Juction B 1000mm (?)

Re: Di2 wire lengths

Posted: Tue Jan 23, 2018 10:54 pm
by kode54
depends if you decide to incorporate the handle bar end junction. if that's the case, you'll need a longer wire from junction B to shifter or bar end junction.

what junction do you plan to use? A or the handle bar end one?

Re: Di2 wire lengths

Posted: Tue Jan 23, 2018 10:54 pm
by Weenie

Visit starbike.com Online Retailer for HighEnd cycling components
Great Prices ✓    Broad Selection ✓    Worldwide Delivery ✓

www.starbike.com



Re: Di2 wire lengths

Posted: Wed Jan 24, 2018 12:02 am
by vinuneuro
Probably A. I already have a carbon bar and don't want to buy another one just for this.

Re: Di2 wire lengths

Posted: Wed Jan 24, 2018 2:22 am
by IrrelevantD
If it’s cabled internal, I prefer to go a little long. Not like a couple hundred mm is going to hurt you that much in weight, and any slack is hidden inside the frame.

Re: Di2 wire lengths

Posted: Wed Jan 24, 2018 3:07 pm
by Rob1519
The reps recommendations are fine. No penalty to being a little long but too short is a pain. If bars are wider than 44, you may want to increase the A to shifter lengths.

Re: Di2 wire lengths

Posted: Wed Jan 24, 2018 3:18 pm
by Cemicar
If your concern about longer wires is those weights, never mind them. Those cables only add less than 1 gram per 100mm. Rather, care about the case where any of your cables is too short. It costs $30 or so.

Re: Di2 wire lengths

Posted: Wed Jan 24, 2018 4:41 pm
by vinuneuro
My concern is extra wire length rattling inside.

Re: Di2 wire lengths

Posted: Thu Jan 25, 2018 2:07 pm
by Rob1519
vinuneuro wrote:
Wed Jan 24, 2018 4:41 pm
My concern is extra wire length rattling inside.
If there is cable rattle, Shimano produces a cable (SD-501) tie that attaches to the wire and lightly presses against the inner wall of the bike tubing.

The only rattling I ever had was from an internal B junction. Solved with a little foam.

Re: Di2 wire lengths

Posted: Thu Jan 25, 2018 4:44 pm
by kode54
before Shimano made the reusable cable ties, regular cable ties were recommended, leaving the tail on it instead of trimming it like usual. the reusable ones are nice since you can move them around the length of the wire.

too short wire may disconnect from ports when stressed. better to have slack to take up some of the pull when turning handlebars, etc.

Re: Di2 wire lengths

Posted: Thu Jan 25, 2018 6:30 pm
by IrrelevantD
vinuneuro wrote:
Wed Jan 24, 2018 4:41 pm
My concern is extra wire length rattling inside.
as others have mentioned, just get a handful of small zip ties slightly longer than the diameter of the tube. They're cheap, space them out a few inches a part and they'll pretty much hold the cables in place inside the tube and keep them from rattling. I'm even using that technique to keep my Bluetooth/ANT+ unit in place inside the frame. Works like a champ.

Re: Di2 wire lengths

Posted: Thu Jan 25, 2018 6:30 pm
by Weenie

Visit starbike.com Online Retailer for HighEnd cycling components
Great Prices ✓    Broad Selection ✓    Worldwide Delivery ✓

www.starbike.com