Rostra electronic cruise control

Prospect

I installed a Rostra electronic cruise control on my 06 Boulevard M50 about a year ago.

Rostra electronic cruise control 20190310

This was not a quick or easy installation. I spend the better part of several days on this. I would not recommend this to less than an accomplished mechanic. The attachment to the throttle must be safe, secure, and reliable to avoid a potential disaster. I’m not offering this as a how-to or instructions; rather just showing what I did. BTW while Rostra acknowledges “creative” installations on motorcycles and ATVs, they do not support such installations, so you are on your own.

The most difficult part was the throttle connection. The kit provides a few means of attachment to the throttle, but I did not use them. I used a metal R/C clevis with a keeper, a shaft, and a custom bracket with guide. I drilled a hole in the tab stop on the throttle butterfly – this tab rests against the idle screw at closed throttle and a stop at WOT. By placing the hole for the clevis near the end of this tab, I was able to get the required 1-5/8” of linear travel required as described in the Rostra instructions.

Rostra electronic cruise control Thrott10

The throttle tab needed to be bent a bit for smooth operation. I ended up building a special tool to do this, to avoid having to remove the throttle body from the bike. This alone took several hours of trial and error.

The photo show the throttle closed with the Rostra cable attached. As the throttle is opened, the cable slides back into the cable sheath. The Rostra model that I used, 250-1223, employs what Rostra calls “lost motion”, so this is the proper way to make the throttle connection. In cruise mode the Rostra of course pulls the cable.

Rostra electronic cruise control 20190210

Next most difficult was placing and mounting the servo/control unit. I had already used the space on the right side of the bike near the ECU (not sure the Rostra would fit there anyway). I found barely sufficient space behind the tool kit box on the left side. I simply bent the Rostra-supplied mount and fabricated an adapter out of HDPE to bolt the mount to the frame. Sounds simple, but I spend several hours determining that this was the right location and getting the bends just right. (More photos to follow).

I had to cut away a portion of the tool box, and then close it up with sheet aluminum using pop rivets to fasten and RTV to seal. There is still plenty of room for tools, as the cover itself contains significant volume.

The cable was routed up the frame to the right and looped around to the left.

Electrical connections were fairly straightforward. I used the auxiliary power connection in the headlight bucket. The required Vehicle Speed Sensor (VSS) signal is at the headlamp, as is the clutch switch. The latter is connected to the Neutral Safety Rostra input, so that squeezing the clutch disengages cruise control, as does brake application. I used a relay to make the required connection to the LED brake light per Rostra instructions.

I did not use a Rostra control switch, as they don’t make one for motorcycles. I used a momentary on – off – momentary on toggle switch, mounted in place of the hazard lights switch. (I didn’t think that switch was too useful. A replacement could easily be connected and mounted at the back of its original location). I did not use an on-off switch for the cruise itself, as one is not really needed. You use the toggle switch to engage, and tap the brakes or squeeze the clutch to disengage.

I spent some time fine-tuning the Rostra setup DIP switches, particularly the settings for “Gain” and “Engine/Setup Timer”. These affect the response to hills and load, and how much or little the cruise drops speed and recovers. It’s still not 100% perfect, but works well enough and much better than a throttle lock.

Prospect

Servo mounted behind tool box:

Rostra electronic cruise control 20190211

Tool box modified to make room for the servo:

Rostra electronic cruise control 20190311

Valued Member

that's a great write up with great pics too, very interesting as you said it was a lot of effort and knowhow to get done are you happy with the result . My skill set would not enable me to do this so hats off to you sir for sharing.

Prospect

Yes, happy with the result. As I stated, it could still use some fine-tuning. The Rostra terms "Gain" and especially "Engine/Setup Timer" are a bit cryptic. The Rostra is made for automobiles, and there is no direct setting for a two-cylinder engine. It works very well on the mostly flat roads here in Florida, but on a trip to the mountains it did slow a few mph going uphill. I think it just requires more experimentation on my part to get the right settings dialed in.

Member

I admire your ingenuity, not something id ever attempt lol

Very Valued VIP Member

Hi, sorry I'm not really replying to this thread. I'm hoping someone can correct what I'm experiencing, it seems the site thinks I'm a non member, its rare I can see any posts or pictures. I haven't been asked to contribute financially which would be happy to do so, as I have done in the past. Could someone contact the administator on my behalf, I'm tried to contact without success, Thanks. (stingray)

Valued Member

hi john just seen your post will see if I can contact admin

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