Beating The ~80 MPH Limit of the GL1500's Cruise Control

For the past 13 years - ever since its introduction - riders have been looking for a way to extend the maximum speed at which the cruise control could be set.  The efforts that I'm aware of approached the problem with the thought of "fooling" the cruise control unit into "thinking" that the bike was going slower than it actually was.

After hearing a few trike owners comment that their maximum cruise control setting was different - lower - than a stock Wing's, and that the final drive gear ratio was normally changed to give the trike more power to pull the extra weight, I did some digging in the shop manual and found that 

    1) My 95 Aspencade's Cruise Control sensed engine speed as well as road speed, and 

    2) There were inputs to the Cruise Control from 4th and 5th gear positions.  

Sure, the fact that there was still input from the speedometer meant that road speed could still be the determining factor, and, since the Cruise Control will only work in 4th and 5th gears, the inputs could merely be giving the CC that information, but -- more tests were in order.

First, I determined, by road test, that ~80 mph CC limit was the same in both 4th and 5th gear.  I also noted that the actual (GPS indicated) speed was always 78 mph, while the speedometer would indicate between 78-81 mph on any given ride, although the engine RPM was always the same.  I took this as another indication that engine speed, not road speed, was the determining factor for maximum cruise speed.

It now appeared that the solution to the problem could be to try to make the CC think that the transmission was in 4th gear, although it was actually in 5th.  Now, how to do this.  Examining the manual (see diagram) showed the color code of the wires inputing the transmission sense into the cruise control, and also showed a connector - C33- where these wires could be accessed after inputs had gone to the engine control system.  After all, I only want to fool the Cruise Control, and not the engine control module. 

The picture (below) shows where this connector is located.  The picture was taken by someone standing in front of the right saddle bag; the shiny black surface in the lower right of the picture is the front of the rear fender.  Even though the picture caption states that the trunk is removed , as you can see by the location of the shock, it's only necessary to remove the seat to get to it.

For the test, I merely cut the red/white and green/orange wires, and cross connected them, so that the CC thinks the transmission is in 4th when it's really in 5th, and 5th when it's really in 4th.  Now for the road test!  I set the cruise control in 4th gear and tapped up to increase the speed.  Sure enough, 65 mph was as high as it would set.  Shifting into 5th, I reset the cruise and, again, started tapping up to increase the speed.  75... 78... 80... 85! Yes! and 90 mph.  The cruise control maintained 90 mph as well as it used to maintain 75.  I figure that it will set up to 100 mph and 4500 rpm (which is 80 mph in 4th gear.)

I know that it works on a 95, and I'll be trying it on a 96 in the next few days.  I believe that it will work on any GL1500 that senses engine speed with the cruise control.  For now, I think I'll leave the wires crossed; I don't foresee a reason to want to use the cruise control above 65 mph in 4th gear.  A couple of other ways that should work, and that I may try later are:

    1) Cut both wires, connect the red/wht wire (4th gear) from the cruise control to ground, and leave the other wire disconnected - I could then engage the cruise in any gear up to what ever speed 4500 rpm is, or

    2) Cut both wires, leave the grn/org wire to the cruise control disconnected, and connect both wires from the shifter to the red/wht wire coming from the cruise control using a diode in each wire with the cathodes away from the cruise control.  I could then set the cruise control up to 80 mph in 4th gear and 100 mph in 5th.

Disclaimer:  This worked for me, but it may not work for you.  If you decide to try it, and break something (including yourself) that is expensive to repair, don't blame me.  

If you should decide to experiment with this, I'd be interested in hearing your comments, questions, and/or about your experiences.  me .

September 23, 2001

To date I've heard from two riders who have modified their '98SE's (one was a European version) with the desired results.  At least one opted to relocate the pins in the plug to avoid cutting the wire.  I've decided that is the way I'll go in the future; I won't install the diodes, since I can't see why I would ever want/need to set the cruise control faster than 65 mph in 4th gear.  

Another person commented that setting the cruise control in 4th gear, shifting to 5th, and pressing "resume" results in the Wing accelerating.  This makes sense, since the engine is trying to return to the same RPM in 5th gear that it was running at in 4th.  I had never noticed it, since I seldom engage the cruise except in 5th.

From what I'm hearing, 93 seems to be the earliest year that this works on.  I've had several reports of negative results with 92s.

Return to my Wing page

Return to my home page

Last Updated on December 29, 2007