Leaning rear

I'm looking to hack up my 2000 Moto Guzzi Jackal into a [URL="https://www.manualslib.com/products/Moto-Guzzi-California-Jackal-4053748.html"]manual[/URL] (leg powered) leaning trike with 2 wheels in back. I know that complicates matters a lot. That's ok. Even if it never works, I want to know every single reason it won't work before I give in.

I would like to know every way anyone has ever done that, with close up pictures. But I will settle for whatever ya got.

Specifically, I am looking for a solution to the problem of leaning the bike in relation to the rear axle, while also transmitting power to that axle. In a way that does not impart wheel drive torque to the lean. And keeps the rear perpendicular to bike centerline.

Don't worry about a differential, I can use a spool. Just transmitting power and leaning. I already have a solution to differing wheel speeds through a turn, and that happens at the outer end of the axles near the wheels. That should simplify things a bit.

Edit: I've never worked on VWs and didn't realize [URL="https://www.jbugs.com/product/211501331B.html?utm_content=shopping&msclkid=65fb55908a6b11e1c27a35d5b483b15e&utm_source=bing&utm_medium=cpc&utm_campaign=***All%20Products%20-%20Bing%20Shopping&utm_term=4585100929598502"]their narrow CV joints[/URL] were exactly what I was looking for.

Also, maybe I wasn't clear on the design. The 2 rear tires will be square profile car tires and will not lean. A beam runs between the rear uprights to define track width. Floor bars are welded perpendicular to that beam which run alongside the bike, curving to meet at the front of the engine cradle pivot point. A second pivot point is at the final drive which is what I was talking about. Floor bars remain parallel to the ground so I don't have to put my foot down at stops, and I can push off of them to initiate, hold, increase, or decrease lean angle without having to wait for vehicle dynamics to settle, or trusting electric or hydraulic systems. No counter steer required, but steering may be twitchy. Basically ignore everything below this line, because it is now solved. But I'll leave it to document the thought process.

The first thing that comes to mind is a "drive sphere", where the axle passes through a steel sphere. The drive sprocket/pulley/cush drive center hole fits right over the sphere, allowing them to pivot in relation to each other. How to transmit drive? Cut mating splines or ball grooves. Except that groove geometry on the sphere never seems to work out.

Second idea, take 2 CV joints and weld both outer housings to the sprocket/drive flange. It should work, but alignment, and welding to CV housings sounds finicky. Also causes lots of unnecessary axle movement, making pillow blocks unnecessarily complicated. Potential ground clearance issues.

Cardan joint, sprocket attached to center section. Easier to build, same problems with unnecessary axle movement.

Single CV joint? Somehow extend the left shaft through the center element to also become the right shaft. Weld sprocket to outer housing over joint center. Requires removing outer housing from its shaft and 'floating' the housing over the center element. Might work, sounds sketchy and weak. Maybe there is a finished product like this already used for a different purpose. What?

Anything else? Has anyone here done this? What did you do? How well did it work out? Pictures?

So far it looks like finding the narrowest possible Cardan joint is the frontrunner.

The existing final drive looks like this [URL]https://www.ebay.com/itm/2001-Moto-Guzzi-California-Jackal-Rear-Final-Drive-022285-/383382273072[/URL]

I could maybe open up the outside of the final drive case and put a small Cardan shaft right in there, splined to the original drive.

No idea how that would work. It would probably remove necessary bearing bores and never hold gear lube again.

Make up a new torque tube/swingarm to kink the final drive over to the bike centerline.

Is anyone aware of a lightweight torque tube style rear end center section? They must exist in auto racing, but that isn't my scene.

Does any of this sound practical? Possible?

Dustin Maki

slomobile robotics