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Rostra Cruise Control Question

F

fruffing

Guest
Guest
I plan to install the Rostra unit on my 2012 Concours 14. I know there is a VSS Signal I can use, but is it available in all speeds in all gears, or just in the top 1, 2 or 3 gears? I like to use CC at low speeds in low gears; back roads etc. If not, I might use the magnetic pickup. Anyone know about the VSS signal with respect to which gear bike is in? I have successfully installed this unit on my Honda ST1100 using magnetic pickup.

Thank
Frank
 
The VSS on a C-14 is a sensor that senses the bevel gear on the final drive rotation. So it has nothing to do with what gear the bike may be in, or even if it is in gear at all- it will work with the bike in neutral as long as the rear wheel spins.

My experience with using the Rostra in low gears at low speeds is that it becomes much too sensitive and over- corrects for speed changes. Again, IME, the Rostra is not usable at, say, 25 MPH in any gear other than sixth without being very jerky at best but usually totally unusable due to sudden and violent acceleration.

Of course you can use the magnetic sensor and some magnets on the front wheel to have the Rostra sense the bike's speed. I have no experience with this though and so have no input on how well this setup works in lower gears. ??

Brian

Frank said:
I plan to install the Rostra unit on my 2012 Concours 14. I know there is a VSS Signal I can use, but is it available in all speeds in all gears, or just in the top 1, 2 or 3 gears? I like to use CC at low speeds in low gears; back roads etc. If not, I might use the magnetic pickup. Anyone know about the VSS signal with respect to which gear bike is in? I have successfully installed this unit on my Honda ST1100 using magnetic pickup.

Thank
Frank
Click to expand...
 
Brian, Thanks for the detailed answer; it was exactly what I needed to know. I have a rostra unit on my ST1100 using 6 magnets on the rear wheel to sense speed. It works very nicely from 40 to 70 MPH, in any gear, but over 70 wants to just keep accelerating. I am guessing that with 6 magnets, the pulses are too close together and the circuitry is missing pulses as I go faster and therefore the Rostra thinks the bike is going slower. I am going to try 3 magnets and see if that resolves the problem at higher speed. That may require some switch setting changes or may causes the problem you describe at lower speeds. Tinkering keeps me out of trouble.

Again, Thanks

Frank
 
The DIP switches have to be set to match the number of pulses per mile that input will yield; on a C-14, the VSS will provide the max. number of pulses the Rostra can handle. Six magnets per wheel will provide far fewer pulses and the DIP switches 3 through 6 set the Rostra to operate in the range of pulses received. It sounds as though your ST1100 setup may not have been quite right for the number of pulses per mile?

On a C-14, set up per my instructions, a Rostra will work from approx. 20 MPH to 120 MPH (or so I have heard....) correctly.

Some vehicles have too rapid a pulse train to work properly with a Rostra, for example an FJR, and require an electronic divider to bring the pulse rate w/in the range of the Rostra.

The DIP switch setup is on page 8 of the Rostra manual, and the table includes the pulses per mile (and kilometer) for each DIP switch combination possible.

Brian

Frank said:
Brian, Thanks for the detailed answer; it was exactly what I needed to know. I have a rostra unit on my ST1100 using 6 magnets on the rear wheel to sense speed. It works very nicely from 40 to 70 MPH, in any gear, but over 70 wants to just keep accelerating. I am guessing that with 6 magnets, the pulses are too close together and the circuitry is missing pulses as I go faster and therefore the Rostra thinks the bike is going slower. I am going to try 3 magnets and see if that resolves the problem at higher speed. That may require some switch setting changes or may causes the problem you describe at lower speeds. Tinkering keeps me out of trouble.

Again, Thanks

Frank
Click to expand...
 
The other big factor in smoothing the Rostra out is putting an extension on the the throttle arm. It reduces the angular/rotational movement of the throttle for the linear movement of the Rostra throttle cable. First I saw on this was a post from FartyMarty.

Thanks, Marty!!
 
Thanks again guys. I know the Rostra can handle a high pulse rate, but I wonder if the pulses generated by the magnetic pickup get distorted or run together with the long twisted pair that carries them. More experimenting to do. Wish I had an oscilloscope. Brian, I will use the settings you recommend on the Concours. The CC made my ST1100 a much nicer bike and I expect he same on my Concours. Then I plan to add to my Pacific Coast. Why Kawasaki never added CC to the Concours has me puzzled.

Frank
 
I would say the Rostra on the Concours or other bikes for that matter is far from perfect but it is certainly a whole lot better than a throttle lock. Thanks to MtnRider I was able to get mine dialed in. I did opt for the Audiovox control unit over the Rostra because I feel it is much easier to use. No engaged light but I guess I could add that if I really feel the need. I'm still waiting for my weather proof on/off switch to get here so I can have a 2nd way to kill power the unit completely if needed.  I mounted mine under the right fairing above the air intake on the right side and it fits very nicely there as opposed of down behind the radiator. The mounting brackets takes some work to get right but not too bad. The bead chain is the way to go over the loop cable. For me the loop cable was way too long.  Good luck with the install but it sounds like you have done it before on other bikes so you should be good to go.
 
I installed the Rostra just a month ago. i too mounted mine under the right panel on top of the air intake. The cable points to the left and runs over the top of the frame just in front of the gas tank and relay mount behind the steering head. The cable loops down behind the expansion tank for the radiator and up to the throttle arm. One advantage is that puts the dip switches on top of the unit so if a change is needed I remove the right inner panel and there they are.
I hooked to the VSS and have no problems.
No need to mess with magnets
 
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