Tilting trike pivot location

I'm planning to build a 2wd tilting delta cargo trike (two wheels in the back). What height would be best for the pivot to allow it to right itself after a turn? Should the pivot be above, below or on the centre line of the rear wheel axles?

Thanks

When the pivot point is above the Center of Mass (COM) the rider leans into a turn, but does that by swinging their body mass to the outside of the turn, more tippy that way.

Conversely moving the pivot point below the COM as a rider leans into the turn, they shift more body mass to the inside. However its a confounding feeling to stay balanced upright. At either side of the "peak" (centered) the seat tends to encourage flopping over.

There are some interesting things that can be done with multi-link geometry.

Thanks for your info Triketech:
Does that mean that having the pivot inline with the centre line of the (motor) axle would be the best compromise? I'm trying to also keep it simple by having a single pivot attached to the rear of the front section of frame with a lock so it does not tilt at low speeds/slippery conditions.

If the axle height *is* the center of mass (isn't always, you'd have to determine that for your trike/rider combination, and it will change when you change mass location on the trike, cargo, have different mass on the tilting portion, etc), then it might be the best compromise.

But if the axle height is not the center of mass, then axle height is probably not where you want the pivot.

You may have to experiment with where it goes, based on how it rides after you build it...which is a PITA because it may require rebuilding a number of parts to do it. :/

That was how I was going to determine it, back when I was considering turning the BarkFiet idea into a trike (though I never have gotten back to that design to do anything with it--SB Cruiser trike has been useful enough on it's own, and much simpler design. Due to SBC's low center of mass, and having the heavy hubmotors in the rear wheels, it's pretty stable in turns even at speeds nearing 20MPH. Would have to be wider or lower COG to do it faster than that. If I moved the seat down a few inches (taking space away from the cargo seatbox) and removed the canopy and rear top rack, it'd be enough lower COG to possibly just exceed 20MPH as the turn limit without pulling the inner tire off the ground. But even right now, I've never tipped it over or lost control of it in a turn, even under circumstances where the inner wheel does come up off the ground.

Regarding a locking mechanism, a number of people have simply used a cheap disc brake rotor on one side of the pivot, and a cable-operated cheap caliper on the other, using a locking brake lever (parking brake style) on the bars to control it.

Triketech said:

When the pivot point is above the Center of Mass (COM) the rider leans into a turn, but does that by swinging their body mass to the outside of the turn, more tippy that way.

Conversely moving the pivot point below the COM as a rider leans into the turn, they shift more body mass to the inside. However its a confounding feeling to stay balanced upright. At either side of the "peak" (centered) the seat tends to encourage flopping over.

There are some interesting things that can be done with multi-link geometry.

Click to expand...

Wouldn't counter steer make more sense then body movement? Just like you do on any two wheeler, being it a bike, e-bike, motorcycle or even the three wheeled Piaggio Mp3?