Measuring di2 cable wiring for dura ace

[Tricky76]

Hi everyone. I am about to order a shimano dura ace di2 2017 groupset from a vendor who was recommended to me from you fine folks here on ww.

Anyway I have no idea about cable lengths - and dont want to order too long or too short obviously...anywhere I can get some guidance? The website is giving me a drop down of size choices for 6 wires...the EW-SD 50 - the length choices go from 150MM up to 1400MM - and I have no idea how to choose.

the wiring is going to be on a pinarello F8 - 51.5cm. also will be utilizing the Pro VIbe Aero cockpit with the junction box in the bar end.

thank you all!!

[BdaGhisallo]

What ever you do, hedge on the longer side of what you think you'll need. A few cm of cable extra can be quite useful. A few cm too few... not so much.

[wheelbuilder]

Not looking at a tech site with exact measurements, but ballpark based on memory.........(please someone correct if wrong)

shifters to junction A...........350?
Junction A to Junction B.......950-1000
Junction B to rear derailleur.......750
Junction B to front derailleur......350 or less
Battery to Junction B..........depends on location, but 500?

[goodboyr]

Give yourself a bit more room on junction b to battery and junction b to fd, just in case you have internal complications around the bb.

Sent from my SM-G900W8 using Tapatalk

[Tricky76]

Thank you all for the replies...after reading more on this forum...here is an added query...what might I use the new Shimano EW-JC130 Y cabling for, if anything....I know I should truly be asking my chosen mechanic these questions...but of course, I haven't decided which of the two I am going with yet....so I don't want to start querying one guy, then have him not end up building the bike.

thanks for the ballpark measurements @wheelbuilder!!!

[lovemyway]

There's a "SHIMANO Di2 WIRING LENGTHS" document for Specialized bikes, you might get some help from there: http://service.specialized.com/collater ... 491_R1.pdf