Electronic shifting servo mount (direct actuation)

thingiverse

The more successful cousin of the cable-actuated servo mount is a direct descendant of regular road-style derailleurs, specifically Shimano. It mounts directly to these types of derailleurs but won't attach to Shimano mountain Shadow-style RDs or SRAM's funky RDs either. This mount can also be attached to older Shimano STX-like RDs that still have a road-style parallelogram body. A significant amount of flexibility exists in this system, making it less than perfect. The barrel adjuster mount broke once due to excessive strain. I've ridden with this setup before and found it to be satisfactory but not exceptional. Various improvements could be made on both the hardware and software sides. Unfortunately, I'm limited in my ability to contribute to the software side. Assembly & Materials To use this system effectively, you must disable or cut the central spring or springs in your RD. A medium-strength servo can be used with this setup, but it's recommended that you only use a single-spring RD so that you can actually disable or cut it. This mount connects to the barrel adjuster and actsuates at the cable clamp. It's crucial that the servo axis is positioned directly over the top left pin on the parallelogram mechanism when viewed from underneath the derailleur, which is mounted on your bike, for optimal results. Updates December 17, 2016: Additional images and information were added to help visualize how the assembly comes together.