by Matt F » Mon Oct 24, 2005 1:06 am
I've been giving this supension qustion a lot of thought. Well, perhaps not a lot of thought, but it comes to mind at odd and idle times. So what I've come up with may or may not be helpful.
My first thought is that the "if you stand on the car, do the damper bodies move?" test might not be quite right.
If you could fix the frame solidly, and then stand on the front wheel, or seriously lift the same wheel, it would droop or bounce. This would pull or push the steering linkage, which would work the rack, and then the pinion, and then move the steering wheel.
So the movement in the front wheel caused the steering wheel to move; but we wouldn't say that the steering wheel is unsprung mass.
I think that a better definition of unsprung mass might involve the bits and pieces that change in geometry as the wheels go up and down. That's pretty simply, but I think it's pretty accurate.
Of course, it's better to have less weight in any of the suspension components. But if the shock and dampener work in a strictly linear fashion, as actuated by rocker arms, I'm not sure that the weight of the components is very important. As long as the springs do their job, and the dampers do theirs, and both are mated correctly, and they are also help within the body of the car, I'm not sure that inverting them would do much for either ride or steering sensitivity.
But, as I said, those are my random thought, and I encourage others.
--Matt
I've been giving this supension qustion a lot of thought. Well, perhaps not a lot of thought, but it comes to mind at odd and idle times. So what I've come up with may or may not be helpful.
My first thought is that the "if you stand on the car, do the damper bodies move?" test might not be quite right.
If you could fix the frame solidly, and then stand on the front wheel, or seriously lift the same wheel, it would droop or bounce. This would pull or push the steering linkage, which would work the rack, and then the pinion, and then move the steering wheel.
So the movement in the front wheel caused the steering wheel to move; but we wouldn't say that the steering wheel is unsprung mass.
I think that a better definition of unsprung mass might involve the bits and pieces that change in geometry as the wheels go up and down. That's pretty simply, but I think it's pretty accurate.
Of course, it's better to have less weight in any of the suspension components. But if the shock and dampener work in a strictly linear fashion, as actuated by rocker arms, I'm not sure that the weight of the components is very important. As long as the springs do their job, and the dampers do theirs, and both are mated correctly, and they are also help within the body of the car, I'm not sure that inverting them would do much for either ride or steering sensitivity.
But, as I said, those are my random thought, and I encourage others.
--Matt