I am sure that Skene just use a simple accelerometer tied to the brake light circuit. The installation instructions for the new Skene controller say that it must be placed horizontal to the bike's line of direction, but not adhered to the bike. It comes in a soft foam shield. I would guess that the controller includes a one axis accelerometer that senses changes in the bike's velocity. If it sees a decrease in velocity but no brake signal, it will read that as inertial or engine braking and trigger the brake light to flash. From a physics perspective, I do not understand why Skene says the K1600 is too heavy to trigger this response.