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Discussion Starter · #1 ·
In my opinion, the Rostra cruise control may be the best option for motorcycles. Its primary advantage is that it requires no vacuum to operate. Needing no vacuum also eliminates the need for the (usually necessary) vacuum canisters and associated tubing. That makes the physical installation easier and reduces the real estate required.

I'm sure there are others much more knowledgeable about the Rostra than I. Even so, I have installed three Rostra's on different types of motorcycles with great success. I offer these hints with the thought in mind to hopefully assist others with success in their installations.

This installation happens to be on my 2011 DL650. I would think the configuration settings (coming later) would also apply to the DL1000 even though the power characteristics of the engine are different.

Placement:
I mounted my servo unit to the headlight fairing frame under the right cowl. Others do the same on the left side. It may be possible to mount the servo under a rear cowling. I like to make custom brackets for a permanent mount, and fortunately, I have the capability to do that. There are other options, though. I have heard that some just cable tie the servo to an available spot. The mounting method and location aren't very critical. Do give some thought to the actuating cable routing. Also, it's convenient to have the dip switches accessible without having to dismantle the bike.

Actuating cable:
The easiest place by far to connect the cable is at the rear throttle body. It's probably the worst place, too. It makes no difference to the Rostra, but it will certainly cause the throttle assemblies to be out of sync. The throttle linkages are designed to eliminate all play when actuated from the front throttle body. If the throttles are opened from the rear, play is introduced. I opened my throttles by hand from the rear throttle body and found that the rear throttle bell crank moved about 1/16" before the front began moving. That's way too much for me.

Figuring out a cable attachment method may not be the easiest part of the installation. The travel of the servo cable is 1 5/8". It follows that the placement of the attachment point on the throttle should also provide 1 5/8" of travel. This is critical, in my opinion. If the cable is attached at a point that allows more than 1 5/8" of travel, it won't be possible to obtain full throttle with the cruise control. This may not be important in level country, but becomes more so on mountain grades, in high winds, riding two up, etc. Having less than 1 5/8" travel is worse. It has the potential to cause damage to the linkage or the cruise control.

The front bell crank is not large enough in diameter for an attachment point that will provide 1 5/8" of travel. It will be necessary to fabricate something if you choose to attach there. Here are a couple of pictures of what I did. Click on them to see a larger picture.

The first is with the throttle closed:




You can see the small bracket that holds the cable housing and the extended arm where the cable attaches.

Here's another picture




And finally, with the throttle opened, you can see how the bracket attaches to the bell crank:




Wiring:
The wiring harness was made for automobiles, so is excessively long for a bike. I cut it down to match my installation. I'm assuming that's what most poeple do.

I would recommend adding a brake relay. The Rostra requires a ground connection on the violet wire in order for the cruise control to engage. They get this connection by attaching to the light bulb side of the brake light switch. The unit grounds through the brake light filament. They imply that when applying the brakes the 12 volts disengages the cruise control. What actually disengages it is the fact that the ground is effectively removed with the the application of 12 volts. The addition of a relay provides a positive ground connection. The relay is necessary if LED brake light bulbs are used. The other advantage of a relay is it allow a convenient way to add a "cancel" switch. I find it annoying to have to apply the brakes just to cancel the cruise control.

Here is a schematic of a brake relay. Disregard the reference to a blue wire. That was another bike.




Above the cruise control switch is a momentary bat switch. A press of the thumb removes the ground connection and cancels the cruise control.




Configuration switches:
Configuration settings combined with servo cable travel are critical. Be advised that the settings I mention here may not apply if your cable travel is less or more than 1 5/8". What can make the switch selection daunting is that there are 378 possible combinations of settings. It seems most Rostra users suffer from harsh engagement, both from initial set and when re-engaging.

The Rostra was designed for automobiles. As such, we are working with a vastly higher power to weight ratio than originally intended. A particular switch setting that might be only slightly noticeable on a car can be extreme on a bike.

Switches 10, 11, 12 have little drama. Switch 10 is sine wave/square wave input. We use square wave. Switch 11 is manual or automatic transmission. I selected manual. Switch 12 has to do with the type of cruise control switch used. The switches I have seen are all open circuit.
10 ON
11 OFF
12 OFF


The rest of the switches deal with gain, pulses per mile, and engine setup timer. All of these settings interact. Gain is the sensitivity of the unit. Pulses per mile are the pulses per mile of the vehicle speed sensor. Engine setup timer is essentially the rate that the cable retracts on engage.

Gain should be set to "low":
1 ON
2 OFF

Pulses per mile. This is a strange one. It seems like everyone uses a different number, with (I think) 8000 being the most popular.

Doing the math:

Circumference of front tire 84.2"

Revolutions per mile
5280' = 63360" / 84.2" = 752.5 revolutions per mile

4 lobes on speed sensor
752.5 * 4 = 3010 pulses per mile

However, 3010 pulses per mile doesn't work well at all. I'd suggest not even trying it. I found the best overall performance with a setting of 9650 ppm.
3 OFF
4 ON
5 OFF
6 ON

The engine set up timer likewise doesn't make any logical sense. Rostra designates the settings with names like 6 cylinder extra high, 8 cyl low, 4 cyl high, etc. At any rate, choose 4 cyl low.
7 ON
8 OFF
9 OFF


With a cable travel of 1 5/8" and the above settings, I find the cruise control seamless in operation at 55 mph and above. You should, too. The only minor issue I have found is that at 45 mph, which is the slowest speed that I use the cruise control, there can be a slight surge when engaging.

Ron :mrgreen:

Disclaimer:
The above are suggestions. Install and operate a cruise control at your own risk.
 

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I am installing a Rostra on a DL100 and have all the wiring figured out except the gray wire off the switch. What does this wire hook up to? Is it a power wire for the back light?
 

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FORUM GODFATHER.....R.I.P. PAT
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Right. You can connect the gray wire to the red wire.
 

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Discussion Starter · #6 ·
Ranger Ron

Any chance you could repost these pictures?
You bet! I didn't realize they were gone...

Here is the servo mounted under the left cowling. It's attached to the headlight frame.


The cable attachment (throttle closed):


Another look:


Cable retracted (throttle open):


Here's the cruise control switch assembly. The momentary bat switch above the cruise control switch disengages the cruise control when pressed.


Schematic for the brake relay with disengage switch. Disregard the wire color notations.



Ron :mrgreen:
 

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Thanks, Ron. Where do you route the actuating cable from the servo to the throttle?
 

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Discussion Starter · #8 ·
Thanks, Ron. Where do you route the actuating cable from the servo to the throttle?
The servo is mounted with the cable end pointing to the rear of the bike. The cable is routed under the right side of the tank and crosses over to the left side of the frame between the throttle bodies. Then it loops up and around to attach to the front of the throttle linkage bracket. Hopefully this pic will make it clearer.



Ron
 

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salve e scusa per il disturbo, vorrei montare ilò cruise control sulla mia st1300. il modello audiovox cruise control non è più disponibile. potrei montare il rostra? qualcuno ha le istruzioni per il montaggio? qualcuno puo' aiutarmi? grazie e scusa ancora
 

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salve e scusa per il disturbo, vorrei montare ilò cruise control sulla mia st1300. il modello audiovox cruise control non è più disponibile. potrei montare il rostra? qualcuno ha le istruzioni per il montaggio? qualcuno puo' aiutarmi? grazie e scusa ancora

Saluti,

È un sistema abbastanza complesso da installare (e ogni modello di moto è diverso) ma reso ancora più difficile se scritto in italiano. Buona fortuna a te.
 
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