Rostra cruise control problems and troubleshooting

[sailor_chic]

Yep, the Rostra needs a to sense a stream of pulses from the Vehicle Speed Sensor (VSS) at a minimum speed to engage. It won't work with the bike sitting still. On my bike, the minimum speed is about 20 MPH when the unit will engage.

Nicole, please do not dismiss your knowledge on this- you passed 'minimal' a while ago in my opinion. 

The Rostra can be tested without the bike moving by spinning the rear wheel while on the centerstand. However, I really do not like to recommend that method because the CC will not work correctly and it will jerk the throttle open and closed very quickly, making the bike pretty violent on the centerstand. Besides, if the unit passes all diagnostic steps, it will almost certainly work on the road so there is generally no need for the risky centerstand test.

Brian

Thank-you Brian 

[VirginiaJim]

Looks like what they have on pull chain light fixtures..

[shaggs147]

Hi Brian, I checked it with a voltmeter. I can check it for resistance as well though just to be sure, if its that sensitive. I have used the negative from the accessory wire for the n/c connection through the relay.

Cheers,
Mark

[B.D.F.]

I used a plastic sleeve that I <believe> came with the hardware for installation, and slipped it over that chain joiner when done. Also, a piece of shrink- tubing will work wonderfully and is easy enough to remove in the future should that be necessary; if it is snug cold, then it does not even need to be shrunk down with any heat.

Nicole, soldering the connector is fine as long as you are sure no 'snots' (technical term) of solder or flux were left inside that might cause binding later. Any little sliver of solder could cause the ball ends to bind inside that connector if they got into just the right (or is that wrong) position. The problem is that it would shorten the throttle cable effective length because the link would bind at some angle and might not allow the throttle to return to idle.

I am not one to get too excited about what might happen but the cable linkage is really pretty touchy between the Rostra and a C-14's throttle arm. Not much room there and to be honest, the whole ball- chain thingy is a little shoddy to begin with.

And Jim, that IS a pull- chain connector or coupler. Rostra spared no expense.... as long as it was dirt cheap.... for the hardware in their CC's :-)  To be fair, in an automotive connection it would not be a problem but on a motorcycle I am pretty wary of using bead chain and the connectors that go with them; my tutorial suggests using one of the pieces of aircraft cable with the Rostra and not any bead- chain.

Brian

I am very pleased to announce that my Rostra is once again working. Proudly I can say that my workmanship was not the cause of the problem. Instead it was this brass connector that attaches the cable end to the chain. I once again re-installed this connector and then scratched my head on how to keep it closed and prevent the problem from occurring again. Then I came up with the solution of soldering the ends of the brass connector closed. Hopefully this will keep working properly now, and interrupt a 1/4 cent piece of material to cause me discomfort on a long ride again. Let this be food for thought for anybody thinking of using these type of connectors that are included in the kit.

[B.D.F.]

That is fine as long as the voltmeter was connected to +12 for the ground check and showed full battery voltage (whatever it is / was on your bike). What is not a good way to check it is to connect a voltmeter to ground and the relay leg on the other side and toggle the brake light on and off: that will result in a reading of system voltage and then close to zero but that is a false reading because a lack of connection to ground would also result in a close to zero reading. So if checking with a voltmeter, I would suggest checking it with the brake light on with the meter connected to ground (should read between 12.0 and 13.0 volts with the engine off), and then checking the same wire with the brake light off and the meter between that same wire and a positive point on the bike.... and the voltage reading should be the same, between 12.0 and 13.0 volts. If that check shows nearly zero volts, there IS a problem with the ground side of the brake light circuit.

Brian

Hi Brian, I checked it with a voltmeter. I can check it for resistance as well though just to be sure, if its that sensitive. I have used the negative from the accessory wire for the n/c connection through the relay.

Cheers,
Mark

[B.D.F.]

I replied to this post but put the response in the new thread "Rostra cruise control problems and troubleshooting" so in the future, other people will find it more easily.

This is a link to that thread and post: http://www.zggtr.org/index.php?topic=19268.msg238005#msg238005

Brian

Hi Brian, I checked it with a voltmeter. I can check it for resistance as well though just to be sure, if its that sensitive. I have used the negative from the accessory wire for the n/c connection through the relay.

Cheers,
Mark

[shaggs147]

Well break open the scrumpy and Cornish pasties...... Finally success - big thanks to Brian and everyone else who chipped in with ideas. After Brian mentioned the resistance to ground I checked the connections again, but this time I stripped back the Negative just before it went into the Rostra unit. I first checked it with the volt meter and there was 0.01v difference between true negative and the negative going to the Rostra. Just above this is a factory Rostra splice. I cut this out and soldered a new connection. Tested it and all works, thanks everyone!
I've only really tested the unit for a few miles down the motorway and although good, it seems a little agricultural, and surges at lower speeds. I have a few millimetres of play in the cable when its at rest. Will I need to change the dip switches slightly or is this normal on this unit?

[rwnielsen]

I'm getting ready to buy one of these CCs and these threads all hold my attention. I'm no stranger to a soldering iron and shrink tubing but I'm still apprehensive about all the bodywork. I should just go for it, there's certainly plenty of help here if I get jammed up.

[VirginiaJim]

The bodywork is the least of your worries...

[rwnielsen]

That's the spirit

[B.D.F.]

The Rostra is not very well setup for high power / low weight vehicles, such as a C-14. Remember, this device was made for autos with a much lower power- to- weight ratio. This is the cause of the surging. You can minimize it by using the highest possible gear for a given speed, this in effect reduces the power- to- weight ratio on the bike and is fairly effective. The CC will work down to 25 MPH but either 5th or 6th gear must be used to 'tame' the engine's output. If you use a lower gear, the bike will surge. At this point I will point out that I will not debate the idea that this is 'lugging' the engine or in some way bad for the bike, I am merely pointing out that it is what is required to use the Rostra on a fairly powerful motorcycle at very low loads (low speeds). Even at fairly high speeds of 50 MPH and higher, the system will oscillate (surge) if very lightly loaded, such as going down a long grade for example. Your Rostra is not defective or not working right, it is just a limitation of this use.

Other DIP switch settings may well work better; they are reasonably well documented in the instructions although badly miss- labeled as to what they are. Still, the basic ability in there in the Rostra instruction booklet and I would encourage you to tinker around with it; you may find a setting(s) that works better and you will absolutely not cause any harm to the CC or the motorcycle by changing the "engine size" or "gain", switches 7,8, and 9 and switches 1 and 2 respectively. The cruise control will respond differently depending on these settings and may get somewhat abrupt and harsh but not harmful. Do not change other DIP switches; they are required to be set where they are in the tutorial (other than switch 11) and should not be changed for use on the C-14. Let us know if you find a setting(s) you fine works better for you.

Brian

Well break open the scrumpy and Cornish pasties...... Finally success - big thanks to Brian and everyone else who chipped in with ideas. After Brian mentioned the resistance to ground I checked the connections again, but this time I stripped back the Negative just before it went into the Rostra unit. I first checked it with the volt meter and there was 0.01v difference between true negative and the negative going to the Rostra. Just above this is a factory Rostra splice. I cut this out and soldered a new connection. Tested it and all works, thanks everyone!
I've only really tested the unit for a few miles down the motorway and although good, it seems a little agricultural, and surges at lower speeds. I have a few millimetres of play in the cable when its at rest. Will I need to change the dip switches slightly or is this normal on this unit?

[sailor_chic]

Brian, you know that I am one that pays attention to details, and now you have me concerned that I have chosen the wrong path of repair. Here comes another sleepless night worrying.

[just gone]

Brian, you know that I am one that pays attention to details, and now you have me concerned that I have chosen the wrong path of repair. Here comes another sleepless night worrying.

You're probably good girl, although Brian could be right about the solder causing the balls to bind in the brass connector. I think the ball chain is the way to go for the linkage, because it seems it would be less likely catch on anything, and even if it did the return throttle cable and your wrist are robust enough to overpower it and force the return (certainly robust enough to over power {dare I say it?} any binding balls). If the cable that Brian prefers were to hang up on something I think it would be more difficult to overpower. However if you ever go back in there, I'd put the tubing over the brass thingy like like Brian mentioned. 

...and now for something completely different...(easy max') ...and yet related...

I thought I had a problem with my linkage hanging up a couple of times. When I came to a stop my idle was around 2100-2200 rpm and even with a helper on the other side of the bike I wasn't able to correct it by shaking rocking the bike left and right with the throttle wide open (ignition off). We continued on and I used the CC for about another hundred miles and when we arrived at the hotel all was normal. This happened a couple of more times later on that trip and I was just about to remove the plastic when it occurred to me what was causing it and I was able to recreate it. I had powered off the cruise control while it was engaged by hitting the off switch instead of tapping the brake or clutch lever to disengage it first. Apparently if powered off in this manner, my actuator stays where it was instead of returning to the home or idle position. Anybody else experience this? Needless to say I don't do that anymore.

[B.D.F.]

Now that is really interesting.... especially since it should not happen.

There are two parts to the Rostra actuator, one is a linear drive, which is what actually provides the 'pull' that opens the throttle. As it is screw based (Easy Bosy!), it cannot be driven externally, meaning it cannot be moved to a new place no matter how much pressure is applied externally. If the unit was at, say, 1/4 open throttle and all power to the actuator was lost, you would not be able to overcome it by twisting the throttle even if you used a pipe wrench. So there is a second device in-line with the drive, a magnetic coupling. When power is cut, the magnetic coupling disengages and the throttle is again free to move and unaffected by the Rostra actuator.

It sounds like you screw drive is shutting down BUT the magnetic coupling is not, which is a very dangerous thing to happen. I believe that would be a defective actuator to cause that as the magnetic control of power is internal to the actuator, not external. You may want to investigate that a little bit more. There is no condition where you should be able to shut down the Rostra as a cruise control and yet leave the magnet coupling active that I am aware of or could imagine.

Brian

<snip>

...and now for something completely different...(easy max') ...and yet related...

I thought I had a problem with my linkage hanging up a couple of times. When I came to a stop my idle was around 2100-2200 rpm and even with a helper on the other side of the bike I wasn't able to correct it by shaking rocking the bike left and right with the throttle wide open (ignition off). We continued on and I used the CC for about another hundred miles and when we arrived at the hotel all was normal. This happened a couple of more times later on that trip and I was just about to remove the plastic when it occurred to me what was causing it and I was able to recreate it. I had powered off the cruise control while it was engaged by hitting the off switch instead of tapping the brake or clutch lever to disengage it first. Apparently if powered off in this manner, my actuator stays where it was instead of returning to the home or idle position. Anybody else experience this? Needless to say I don't do that anymore.

[B.D.F.]

Well, I do not know that I would lose sleep over it and I do not think it is by any means likely to bind. I was merely mentioning it because I think perhaps a better way to go is to leave the ball coupling clean and just slip a plastic tube over it to retain the balls and prevent the chain from possibly coming apart or binding. More for future installers than yours, which is already done. But hey, if it really does bother you, change the coupling and use a snug fitting piece of tubing and I promise it will last forever and never bind. :-)

There are several places in that paragraph above that require an 'Easy Boys' so I am just putting it here as a blanket disclaimer.

Brian

Brian, you know that I am one that pays attention to details, and now you have me concerned that I have chosen the wrong path of repair. Here comes another sleepless night worrying.

[shaggs147]

After more tests today at 50 and 70 mph I'm a happy chap. Bike holds steady at both speeds using Brian's dip switch settings. As Brian mentioned, it works at its best and is nice and smooth in top gear. Time to tidy everything up now and put the bike together at last!

Thanks again
Mark

[VirginiaJim]

Don't be a stranger...

[just gone]

Time to tidy everything up now..

Oh sure, just be different than the rest of us.
sailor_chic has started something here for sure. 

  I just can't decide if it's a good thing or not. .....

[shaggs147]

Oh sure, just be different than the rest of us.
sailor_chic has started something here for sure. 

  I just can't decide if it's a good thing or not. .....

Err I've just looked at sailor chic's install and what a lovely professional job that is, well done! Mine will be held up with a few cable ties and hidden by the plastics 
Might even treat the bike to one of its bi annual washes   

[shaggs147]

Don't be a stranger...

I won't Jim. Gradually been reading through the various posts and subjects, its good to see what experiences others have had with their bike and accessories.