Self centering

[alga]

Originally Posted by robo

Not quite the same thing because the trail wont become effictive untill you move where as the caster will be effiective at all times. Hence the lack of self centering when stationary.

I have no problem with lack of self-centering when stationary. I would say it's a feature of most cars. Turned wheels stay turned as long as the car is not moving.

Now, the kingpin inclination angle, which is cast into the upright geometry, should provide some self-centering effect, as turning the wheels results in slightly raising the car, but, apparently, with the Roadster's weight, this effect is not enough.

That castor like on a shopping trolley could be kicked arround 360 degrees and it will only straighten if you move forward. Also the inside wheel on turn in on the proper set up is forced downwards whereas the trail set up remains static.

You're missing the bit that Sierra's upright has negative trail, and offset mushrooms set it to zero, making the wheel axle intersect the kingping axis.