Electrical tape is easier than heat shrink and is virtually indistinguishable from more than a couple feet away. There are new hydraulic brake calipers too, and I recommend using them. Not only has the rotor-to-pad clearance improved, but they also feature new bleed ports which make bleeding your brakes a lot easier. Again, I prefer having too much wire over having too little. The excess wire will be hidden away in the down tube and seat tube, and the performance is the same as that of a shorter wire. Buy the components If the measured length is 325mm, the next size up is 350 and the correct wire length would be 350 + 50 = 400mm

speed and 11-speed Di2 bikes can have the charge port in a couple of locations. If your bike has an internal battery you plug the charger into the junction box – either below the stem/handlebar or integrated into the frame or seatpost. It has a little cover that you can open using a screwdriver or knife. When in doubt, choose a slightly longer wire than you think you need. All wires cost roughly the same, and having a wire that is slightly too long is not a problem - excess wire can be hidden in the frame.Use the remaining ports on Junction A to run electric wires to the battery, front derailleur and rear derailleur You can still build a budget-friendly 105 Di2 rim brake bike - you’ll have to use the Ultegra or Dura-Ace shifters. After nearly a year of testing, the crankset has borne the mileage well. Ashley Quinlan / Our Media

For each wire, measure the length of the frame sections it has to pass through and write down the required length As my colleague, Simon von Bromley, pointed out in his review of the brand’s flagship groupset, Dura-Ace Di2 R9200, moving to a semi-wireless system reduces the chance of issues with adjustment, servicing and routing at the front end of the bike (excepting the continued presence of brake hoses). Like the sibling groupsets, the brains of the system live in the rear derailleur, so there’s no junction box in the mix either. This first method involves running an EW-SD300 wire from one shifter to the other, and then running a single wire from either shift lever to the third port on the battery.Type 3 Port Gear Cable allows has a cable stop, stopping the gear or brake cable housing for the bare inner cable to run internally through the frame. While 12-speed Di2 simplifies things greatly, it isn’t always easy to know whether or not you’ve really bought all the parts you need, and wire lengths generally confuse people too. There are three wires that connect Junction B and the other components. Wire F runs to the battery, H to the rear derailleur and the last wire( G) connects the front derailleur. There are small differences in shift speed, which is detectable at the front derailleur and in the drivetrain smoothness compared to Ultegra Di2 (remember, that groupset is practically indistinguishable from Dura-Ace Di2).

The bottle goes in carefully pushing the delicate cables out of harms way, top or bottom, it's up to you Finally, 11-speed Shimano cranksets do not work with 12-speed Shimano (outer) chainrings, even though the BCD is 110 in both cases. This is due to the design of the crankset - you physically cannot put a 12-speed Shimano outer ring on an 11-speed Shimano crankset. Hydraulic Disc Brake specifics That said, this isn’t an issue isolated to 105 Di2 R7100. I’ve experienced the same across all levels of the latest Di2 groupsets. The length of those wires depends on where you place the JC304 junction. Some people put it in the stem or the handlebar, while others place it in the down tube.

The Shimano Di2 brand

Shifting performance, in turn, is near-identical. With both Ultegra and 105 Di2 derailleurs side by side (set up identically in the E-Tube app), I can’t discern a speed difference between them following a press of either lever button. The junction box on road bikes can be located under the stem, in the end of the handlebars or, on some bikes, mounted in the frame.