How do Harley cruise controls work?

Question

Specifically, does it monitor some setting in the EFI system or does it go completely off of the transmission, etc?

All of them have a throttle lock. The newer electra glides come equipped with an actual cruise control. What does the cruise control module sense/regulate to maintain the desired speed?

Answer 1

Usually a throttle lock, clamping the throttle to a desired position.

Answer 2

Typical cruise control modules, monitor the position off the speedomer's setting. A CC unit that is turned on, as you know, keeps the vehicle at a set speed, regardless of the gear it's in, and has a cutoff switch integrated into the braking system. Models with the friction thumb scre, just hold the throttle open in a predetermined position, and you have to manuall roll back the throttle to slow down.

Answer 3

I don't know about Harleys. Jap bikes with digital speedometers have a "speed sensor" attached to the crankcase. It determines the speed of the bike, by the speed the counter shaft (output shaft) in the transmission is turning. It relays that info to the ECM (electronic control module - computer). The ECM relays that info to the digital speedometer on one circuit. On another circuit, that info is sent to the cruise control "actuator".
The carb's throttle body is spring loaded, so it wants to stay closed. Turn the twist grip and the throttle cable opens the throttle body. The actuator has it's own throttle cable. The ECM tells the actuator to pull on it's cable to speed up. When you're going faster than the cruise speed you set (as in going down a hill), the speed sensor tells the ECM and the ECM tells the actuator to let go of it's cable a little. Since the throttle body is spring loaded, it closes on it's own, until the actuator opens it again. Touch the brakes and and a signal is sent to the ECM which turns off the cruise control circuit.

Answer 4

speed sensor in trani