Racing bikes are wired to track cadence and speed already which is perfectly legal. These signals are sent to an attached computer on the bike. I don't know if you'd be able to separate out that signal.
For cadence and speed, they are very rarely "wired" anymore. Almost all use ANT+ for communication, it's a very low power protocol meant for low power usage.
Electronic shifting (Other than SRAM's newest) is however wired, but again it's a very low power protocol. It also uses two motors to perform the shifts, but they are very small and external.
