Anyone who's built up a Di2 bike with internal wire routing knows the frustration of hearing a faint tick or rattle from inside the downtube on rough pavement—it's almost always the E-Tube wire slapping against the inside of the frame. Shimano's EW-SD50-I Wire Holder is the small piece of hardware that solves that problem, clipping directly to EW-SD50 wires and suspending them inside the frame so they can't move or contact the tube walls. The 20-pack gives you enough holders to handle a full internal Di2 build with plenty left over for future service work.

Each holder uses a flexible C-type clip that snaps around the wire and expands against the inside of the frame tube. The design is supple enough to feed through internal routing during installation without binding, but firm enough to hold position once seated. Because the clips don't permanently deform when opened, you can remove and reuse them during future service—useful when you're pulling wires for a groupset upgrade or troubleshooting a shifting issue.

Holder spacing is left up to the installer and depends on run length, internal tube diameter, and how many corners the wire has to negotiate. As a general rule, use more rather than fewer—a holder every few inches through the downtube and around bends will eliminate rattle across the widest range of road surfaces. These are specific to the EW-SD50 wire; if you're running the newer EW-SD300 system, you'll need the corresponding holder for that wire's smaller diameter.