TRIUMPH ST ROSTRA ELECTORNIC CRUISE CONTROL

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1 TRIUMPH ST ROSTRA ELECTORNIC CRUISE CONTROL There have been a number of threads discussing the pros and cons of electronic vs throttle lock cruise controls. Living in Texas can require some long distance highway pounding to get to the good stuff. Riding with a mate who relaxes knowing that his electronic cruise has him covered while I continually adjust my throttle lock made my decision for me. Disclaimer: Following these guidelines should help you avoid the many pitfalls I fell into. However, fitting a Cruise Control is challenging and must be done to the highest standards of craftsmanship if the finished product is to be safe. In particular you can t allow the cruise cable to snag and lock the throttle open. If you choose to do this it s at your own risk. My bike is a 2007 ST1050 ABS. McCruise have rolled out their plug in version for $850. Tempting, but it s old vacuum technology and four to eight times the price of the Audiovox or Rostra. I figured I had a better than 1 in 4 chance of making one of these units work. So which one: Audiovox: + Can use just the tach signal others have reported difficulty getting the Triumph VSS to work with either unit more later. + Ralphus has already successfully fitted one to this bike. - Old technology - Reported to be larger - Requires taping into the vacuum. Rostra: + Lost motion cable this was the decider. When the unit is disengaged the cable is free to slide into the housing. When you activate the cruise it grabs the cable in it s present position. This eliminates loose cable that can snag, beads or an expensive Cable Interface Unit. + Reportedly smaller + All electronic - Needs a speed signal - No one had yet reported getting one to work on the ST1050 I didn t know it at the time but Tom at Rostra should have been the deciding factor. He has been amazingly helpful and patient. On Tom s advise I ordered my Rostra unit from Joe at Brandon. The unit arrived 3 days later. The quality was better than I d expected. The size was LARGER. Even though I d been told the dimensions it still came as a shock. Without ABS I m told the unit will fit inside the steering head to the left of the air box. With ABS it won t! Iggypop had squeezed the module under his steel tank just in front of the battery. But my plastic tank had been beautifully moulded to fill that space. I made a wooden mock up and spent the

2 next couple of hours trying to find somewhere anywhere to put it. The ONLY place I found was just above the output sprocket and even then the plastic cover had to be notched for it to fit. In fact it fits like it was made to measure, a couple of extra mm in any dimension and I d have been sending it back. This location allows easy access to the dip switches but if you follow these guidelines, and set the switches as suggested, you shouldn t need it. I hate one size fits all brackets, really they don t fit anything. So the first job was to carve a module bracket from 2 *1/8 stainless. A drawing is attached be warned the dimensions and bend are critical. Do the steps in the order indicated and the bends will be neat and sharp. I strongly recommend under drilling the holes and fine tuning with a file. If you decide to skip STEP 4 the bracket works just as well and I don t think you ll notice the extra weight. MODULE LOCATION FROM TOP FROM THE RIGHT

3 The next challenge was attaching the cable to the throttle pulley. Ralphus has what looks like a simple workable solution. But I wanted the cable to pull an arc and stay tangential. The final design is attached. My first design didn t include the tongue and wouldn t push the cable into the housing working on the quadrant it starts pushing at 90 degrees to the cable housing. I made the side plates a close fit to the cylinder head, to trap the cable, but with the tongue it probably wasn t necessary. With the new design the cable slides back into it s the housing no matter how quickly I snap the throttle. It s all attached with a coupling nut, but I had to make one as the needed 7 mm thread doesn t seem to be available. I used 3/8 hexagonal stainless stock drawing attached.

4 CABLE BRACKET 3 PIECE QUADRANT NOTE Rostra recommends threading the end of the cable sheaving. This worked OK but wasn t the factory look I was after. The SS cable end works great but honestly wasn t worth the effort, or cost, of making it.

5 WIRING there s a lot of it and it requires a number of splices. I bent aluminum bar for the left side to duplicate the shape of the relay bar on the right. I thought it provided ample real estate to mount all the pieces but I used it all to be fair I also fitted hazard flashers and relays for the heated grips.

6 BRAKE The LED tail light requires the use of a relay to cut the violet wires path to ground. CLUTCH - Perhaps the most challenging as the ECU supplies only 4.7 volts to the clutch switch. The relay wired in series with the brake relay looks simple but it took me a while to figure this out. The diode (Radio Shack # ) was the key but make sure you wire it the right way on the black wire from the ECU with the grey bar TOWARDS the clutch switch. It meant cutting into the sheathing for the left handlebar switch I couldn t think of any neat way to avoid this. One day I ll probably cover it with heat shrink but for now leci tape will do. An alternative to the clutch switch was to use the Neutral wire but this would cause the unit to loose it s set speed whenever the clutch was pulled. I could also have used the tach wire but Tom recommended against this on a high reving machine with such a high power to weight ratio remember the unit is made for cars. VSS turns out that the signal rate is too high for the cruise. I measured 290 Hz at 20mph or 52,200 pulses per mile. The Rostra can t work with more than 39K or so PPM. Tom told me to purchase a 4X signal divider and set the unit to 12,870 PPM. The Centradyne unit from Taxi Depot can be set to divide by 1,2, 4 or 8 and came nicely finished in a plastic box.

7 SWITCHES I decided to use the CONTURA II switches that Triumph uses for heated grips. These are large, robust and waterproof. The left fairing insert is already marked for one and it was easy to cut a duplicate hole for the other. I considered fitting a micro switch in the handlebar control but decided I like the cruise switches where they can t be accidentally activate. This location is convenient enough for the relatively rare use and touching the clutch or either brake will instantly cancel the unit. The right switch is DPDT and activates the hazards flashers or turns on the cruise I switched the brown wire, not the red as indicated by the Rostra instructions, so that the unit is completely isolated when switched off. The left switch is a SPDT momentary for SET/RESUME. My dip switch settings are also shown this was my first set up and I saw no reason to change them. WIRING LOOM I cut a 1/2 piece of heat shrink to length and notched it for each junction. I then made the loom sitting comfortably in my kitchen. This resulted in a pretty neat set up and much better than running each wire on the bike and then wrapping it in tape. I didn t like the supplied bulkhead connectors so replaced them with a single Econoseal 8 way. The bike plugs into the cruise module to the left of the airbox. TEST RIDE When the unit is engaged it takes 2-3 seconds to catch the cable during which time you MUST maintain the set speed. If you press SET and immediately let go of the throttle the unit cancels I did this on my first test and thought the unit wasn t working!!! Once it takes over the Cruise will maintain any speed over 35 mph to within 1 or 2 mph. WORTH IT? This project has consumed many hours of my time and there have been numerous occasions when I wish I d never started. However, I expect to spend many relaxed hours secure in the knowledge that my speed is set and not worrying about hidden police cruisers. With these guidelines you should be able to do the job in much less time and you ll have something that looks factory fitted even when the panels are off. But only you can decide if it s worth it.