I've never seen the mechanicals of an electric lean suspension, so I'm guessing a bit here and looking for a little confirmation/clarification/refutation on my assumptions.
As I understand most modern electric lean sidecars, the electric actuator does its work by raising or lowering the swingarm pivot and/or shock mount of the sidecar thus raising or lowering the ride height of the frame relative to the tire. By dipping the frame, the bike leans toward the car. Similarly, by raising the frame relative to the road, the bike's leanout is in effect increased.
Is that theory correct?
There are two different items often called electric lean. One, leans the bike with an acutuator and is used for steering. In general, I think this is a bad idea as if any thing at all goes wrong while leaned, even a blown fuse, you can quickly be in a world of hurt.
What you are describing I call electric trim or some times by what Champion sidecars calls it TILT. And you have it correct. Electric trim is really nice to have.
Jay G
DMC sidecars
www.dmcsidecars.com
866-638-1793
jay@dmcsidecars.com
Ah! Thanks for the clarification Jay! I updated the subject of this thread to get the terms right.
Now to look over my swingarm to see if it's a candidate for a retrofit!
Is your sidecar a production sidecar? If so what brand?
Jay G
DMC sidecars
www.dmcsidecars.com
jay@dmcsidecars.com
It's long ago out of production. An Auburn Gemini. I doubt the TwinStar dimensions would be valid as my shock is behind the wheel, not in front.
Here is what my swingarm and rigid shock support looks like:
OldSchool_IsCool - 9/7/2011 4:17 PM
Ah! Thanks for the clarification Jay! I updated the subject of this thread to get the terms right.
Now to look over my swingarm to see if it's a candidate for a retrofit!
I have a photo of the electric trim setup on my Hannigan sidecar frame, taken with the sidecar body off of the frame. Unfortunately, ePhotoBay (which I use to post photos) has a server problem right now and I can't post a photo this morning. Send me an email if you would like a copy of the photo.
Email sent. Thanks Roger!
You would need to mount a rocker to the top of the shock tower, one end of the rocker would go to the shock the other to an acutuator.
Jay G
DMC sidecars
Here is my California Friendship III, extended
And Retracted
jaydmc - 9/8/2011 10:30 AM
You would need to mount a rocker to the top of the shock tower, one end of the rocker would go to the shock the other to an acutuator.
Jay G
DMC sidecars
That's what I'm thinking too Jay, a rocker on the top of the tower with a pivot point on the front side. Something similar to what Mike has (Thanks for the pics Mike!!)
What would be a reasonable range of leanout deflection? If the zero point of the bike is set to say +1* leanout, would a good range of adjustment be +2* to 0* (i.e. 2* of adjustability)?
I've done some rough calculations. The distance from my tug's centerline to the sidecar tire is about 50 to 60 inches (if memory serves). That mean I need about 1 inch of frame rise to increase the leanout by one degree. With the shock at a 45* angle, I would need to change the shock's upper mount by 2 inches per lean degree. With 2 degrees of adjustability, I'm looking at 4 inches of shock mount travel. There are 6-inch actuators available fairly cheap (about $250) so I could have a 2:3 rocker ratio on top of the shock tower to give me the 4 inches of shock mount travel. The actuator I was looking at maxed out at 1000 pounds of pull and 800 pounds of push. The spec sheet didn't mention static load, but prolly more than 1000 pounds. With the actuator having the advantage side of the rocker, that would mean about 1500 pounds of static loading at the shock. That would be about 3 times the dead weight of an extreamly loaded car. With dynamic loads due to say a pothole strike, I think I'm still safe considering that the bike is taking it's share of the load too.
Would take a bit of trial and error to get it to work right, but I think it might just be feasible! I'd want to put in some hard points to limit lean due to component failure while moving. The big trick will be to get it all to fit under the fender. Hmmmmm.
Am I way off on this thought experiment? Any and all comments are welcome!
I would go with 4 inches of stroke. Lower priced acutuators are not recerculating ball type and tend to draw more power and not last very long. We use a 1500lbs capacity acutuator. You also need to make sure that it is rated for some water resistance other wise it will not last. The one we use has a retail price of over $900, we pay a bit less for them which is why we can make the electric trim an $800 option on our sidecars. When acuturators do fail, they tend to fail electricly and as such all that happens is that you are stuck at where ever it was when it failed however if you undo one end you can thread it in or out to where ever you want it to be stuck at as a "get me home" fix.
Jay G
DMC sidecars
www.dmcsidecars.com
Thanks again Jay,
I'll have to look into higher force rated actuators as you suggest. I'd rather overbuild (assuming I actually attempt this). The actuator I was looking at has an IP65 rating. I understand that to mean fully protected from dust intrusion and able to handle temporary liquid immersion. I would imagin I wouldn't want anything less.
Does the 2 degree range sound right to you?
The bigger job at the moment is getting my mounts sorted out. Speaking of which, can you send me more info on your GL1100 mount kit? wesk8 at att dot net is the address.
Thanks!
I don't know what your swing arm looks like, but here is a photo of my Escort. It might help.
