ROSTRA INSTALLATION IN A GL1100I

Above linked document edited: 8-10-07: No significant changes.  Only cleaned up with minor edits.

A number of people here have expressed interest in installation experience with the Rostra Electronic Universal Cruise Control (250-1223). R Kirby (tricky) has already reported one installation on a GL1200 http://www.goldwingfacts.com/forums/view_topic.php?id=12231  although to date,  he hasn’t reported any operational experience.  I have completed my installation on a GL1100i and have about 3000 miles of use (testing) to date and can give relatively detailed summary.  I’ll just give an initial version here and if I complete any more tests, I’ll just update this document.  

Let me give the bottom line first, for those that don’t want to wade to the end.  It is working very well; I’d give it about an A-.  Above 50 mph, it works flawlessly and nearly as well as my GMC SUV (edit 10/15/07: and better than my recently acquired GL1500SE).  And it works quite well 30 to 50 mph too, almost all of the time, but can get in situations (down hills, wind buffeting in traffic, tail winds) that cause it to uncomfortably correct to decrease speed when it would be a little better to be a little less harsh and let it coast.  These, I think, are not unique to this Rostra installation but having to do with more general issues like Power/Weight ratios and a sensitive throttle linkage geometry for this motorcycle that really needs to be addressed to work optimally with a cruise. 

Although I did deviate somewhat from the typical motorcycle installation methods that I see on the Internet, I did demonstrate the same method (hooking directly to the short carb #4 linkage) somewhat successfully.  I do believe that making the Rostra Electronic work with this short linkage setup is a bit of a crapshoot, and if you are not so lucky, you can find yourself spending a lot of time getting it sorted out. The problem is in how the VSS PPM settings affect gain (and Rostra customer service doesn’t even understand).  If you use the magnetic pickup system on a wheel with 6 magnets and set the ppm to 4000, you will coincidentally avoid most of these problems and have a useable cruise, however, if you try to use anything else (like another VSS signal or the tach, or the alternator, etc.) you may find yourself chasing your tail before you find a setting that works. 

Physical installation of the Rostra electronic is, I believe, a little bit easier than a vacuum unit since you don’t have to deal with the vacuum lines and canister; the electrical connections are essentially the same.  But in many cases you will spend all of the saved time (and then some) getting the unit properly tuned to have satisfactory performance, where, if you believe the glowing reports, the vacuum unit (Audiovox CCS100) appears to be pretty much a hook it up, set it and forget situation.  That approach would not have been successful with this ROSTRA electronic installation (and maybe I am overly critical and would not have given a good grade to the Audiovox either). (Makes me want to buy one and do side by side testing, and maybe I will, but that will have to wait, too.).   

A few things are left below as highlights, but all of the pictures are in the referenced document, not here.

Here are a few unique points:
LOCATION FOR MOUNTING: Between right bag and wheel attached to bag frame.

WIRE CONNECTIONS. 
Gray wire
The gray wire is the Vehicle Speed Sensor (VSS) input … My choice is at the turn cancel unit connector (White wire with black trace).  The VSS signal measures 9350 ppm.
Lt Green wire
The light green wire is the neutral switch wire and is attached to the GL1100i to accomplish both the clutch switch and neutral function.
Blue Wire
Not used but comments included on using the tach/coil signal as an input for the VSS (Gray wire). 

THROTTLE LINKAGE, GAIN, TIMERS AND CPU DIP SWITCH SETTING:
Throttle Linkage: Uses 2" radius bar on throttle plate.
Gain, Timers And CPU Dip Switch Setting
Gain (1,2) (Start with LL: Off,Off)
Pulses per Mile(3,4,5,6) (Use 9650 for the ‘83GL1100i: Off,On,Off,On or other as necessary for your application)
it really DOES AFFECT THE DYNAMIC PERFORMANCE …
Engine Setup/Timer (7,8,9) (Start with 8cyl L: Off,Off,Off)
There is more to this setting than meets the eye…. 
VSS Input (10) (Set to square wave signal; the 83G1100i VSS is square: On)
If you are using the magnets then sine.
Transmission (11) (Set to AUTOMATIC!!! : On)
This is not a transmission switch, just the question: Are you using the neutral wire
Control Switch (12) (Depends on the control switch you get; mine was open: Off)
 
TESTING AND TUNING

As mentioned, the first ride was not satisfactory using the 1.5” arm, the lowest gain, 9650 PPM setting, the 4 cyl L setup timer.  It was much more aggressive than would be acceptable (at least for me).  Again, let me digress and say what I mean by aggressive and sluggish:  By aggressive, I mean frequent overcorrection by throttle changes that cause acceleration or deceleration not expected and/or are uncomfortable.  (This is usually due to too much gain with either proportional and/or derivative terms that are too large.)  By sluggish, I mean not correcting as soon as it should allowing slowdowns (and overspeeds) that are not abrupt but interfering and annoying  (This is typically caused by not enough overall gain, or too much integral action and or not enough derivative.)  In the following discussion, note that there are three things that Rostra provides as parameters (Gain, Setup/timer, and PPM setting), although they don’t officially recognize PPM as a knob to twist.  In addition, this installation has provided the length of the control arm as another parameter which is similar but not exactly identical to the Rostra “Gain”

Noting that shortening control arms, selecting higher gain settings, selecting higher timer/setup (meaning a more sluggish vehicle and farther down the list), and selecting higher PPM settings all increase “aggressiveness” (and the opposite selections to make it more sluggish), the tuning experiments began.  I add the summary of results here in shart form without discussion, but it should be evident from the chart below how things work.  I have also attempted to theoretically calculate a “figure of merit” for each setting based on educated estimates of the relative mathematical inputs that is normalized so that ideal is approximately 1.00.  Higher numbers indicate a more “aggressive” behavior and numbers lower indicate a more sluggish behavior. This should be looked at as more qualitative than quantitative.  It is also incomplete as for verification by testing.  Your PPM settings, in particular, may be different based on what you use for a VSS signal but what I want to emphasize is that this number is a parameter too, not just an input related to your VSS speed.  The column called "Actual/Setting" is the ratio of your actual PPM divided by the selected PPM setting.

The color code is this:

Orange: Not Tested but not expected to yield a good result because too aggressive.
Light Blue: Not Tested but not expected to yield a good result because too sluggish.
Yellow: Not Tested but potentially could yield a good result.
Red: Tested and yielded an unusable result because too aggressive.
Dark Blue: Tested and yielded an unusable result because too sluggish.
Light Green: Tested and yielded a useable result but not the best.
Dark Green: Tested and yielded the best result so far.