Motorcycle cruise control mini project#
Posted 2025-05-31
Time had demonstrated that my motorcycle, a 2018 Kawasaki Versys 650 LT, was just about as perfectly matched to my needs as it could possibly be. The "just about" stemmed from its lack of cruise control -- sorely missed during long highway stretches on road trips. As I contemplated 2025 summer road trips, correcting that one deficiency seemed necessary.
Fortunately, I found posts by a couple other Versys owners who had successfully adapted the Rostra 250-1223 universal cruise control system -- intended for passenger cars and trucks -- to their bikes. The kit's price seemed reasonable, so I decided to go for it. (Rostra Accessories, a company based in Orlando, FL, is a maker of "automotive comfort, safety, and convenience accessories".)
The installation rundown
- Tap into the motorcycle's wiring for these purposes (also see Illustration 5):
- VSS - signal indicating the vehicle's speed (as basis for the unit to regulate speed)
- Brake - signal indicating the brake has been applied (to trigger cancellation of cruise)
- Clutch - signal indicating the clutch lever has been squeezed (to trigger cancellation of cruise)
- Add new wiring for these purposes:
- Cruise on/off switch (Illustration 2, item A)
- Set/Coast button -- momentary switch (Illustration 2, item C)
- Resume/Accelerate button -- momentary switch (Illustration 2, item B)
- Fuse-protected power source and ground for unit
- Fabricate interface to the vehicle's throttle-pulley assembly for the unit to physically control the throttle position (Illustration 1, item C & Illustration 3)
- Fabricate a stable and optimal control-unit mounting point (Illustration 1, item A & Illustration 4, item B). The control unit is more bulky than I would like for a motorcycle. In the end I decided to mount it alongside my rear luggage rack, where I previously bolted-in a re-purposed, watertight locking ammo box for everyday storage needs.
- Route and anchor the throttle control cable across motorcycle (Illustration 1, item B & Illustration 4, item C)
- Add electrical and electronic interfaces to translate the vehicle signals to the control unit's input needs (Illustration 4, item A & Illustration 5 wiring diagram):
- Relays to translate the brake and clutch signals
- A "divide by 2" module (Rostra 250-4369) to divide the vehicle-speed signal in half, because the motorcycle's native signal rate -- about 40,850 pulses per mile -- is above the range the control unit can be set for.
Illustration 1 - full width view of components on bike
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Illustration 2 - added control switches at left/throttle handle
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Illustration 3 - fabricated throttle-pulley interface
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Illustration 4 - integrated electrical interface components (in under-seat housing) and mounted control unit
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Illustration 5 - electrical wiring diagram
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The project documentation and drawings I developed are available in this GitLab project for those wanting the full details.
The review
With the addition of cruise control, the Versys 650 has me covered. The cruise control is performing well, and it's refreshing to tap the set button and feel the unit take over maintaining the speed. The installation project was an enjoyable electro-mechanical challenge.