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So, as we know a huge problem inherent with reverse trikes is that the rear tire has no ability to camber, so it rolls up on its edge when turning, because of body roll.


My thought is, what if you were to basically split a conventional swingarm in half, so that there was a left and right side, which could move independently from each other. Then attach each swingarm half to its own shock absorber. Then, at the end of the swingarms, put the rear axle through a huge heim joints rated for thrust loading; one at the end of each independant swingarm half.

that way, assuming the inclination doesn't exceed that of the heim joint, the rear wheel would be able to "twist" wheen the body rolled, allowing the tire to remain planted on the ground.

Obviously, if chain drive, there would be some twisting of the roller chain, but you could solve that with this:

http://www.mcmaster.com/#roller-chain/=lmvrrm

Would this work? if so it would enable the use of much wider tires in the rear, without rolloing up on an edge while turrning.


Ike

I don't think it would work the way you are hoping. When cornering the forces will try to tip the tire the same direction as the body roll. In fact this is the same interaction causing the body roll in the first place Thus this extra degree of freedom you have provided would most likely just cause the problem to be exaggerated even further. In order for such a system to work, it would have to be devised such that it's automatic reaction is to completely resist or move slightly in the opposite direction of a natural reaction to the forces.

What is the matter with those big fat bike tires the custom bike builders use? You might not have a large contact patch but you wouldn't get up on a tire shoulder.

I'm not even sure it's a problem. From what I understand, most reverse trikes understeer, because all of the weight transfer occurs at the front end. Improving the camber of the rear tire would only be a problem if it was giving up too much grip. Reverse trike drivers would know better than me, but I think that's right.

They understeer under pure cornering forces but are prone to power oversteer if there's enough of it.

I don't think a wide rear tire would help because for a given camber angle the inside wants to lift up more.

Maybe if it has quite low inflation pressure.

As for a design that would counteract camber, it would be complex but you could attach the pivot end of the swing arm to a 4-bar that would have its instant center above the roll axis so that cornering force would want to raise the outboard end and lower the inboard end.

Might feel squirrely though as there would be some lateral movement of the wheel.