Front suspension discussion: Jim Musser

Today I called Jim Musser, designer of the Sport Cycle and he was very helpful in explaining how the front suspension achieves the very high roll resistance demonstrated in the Sport Cycle. I asked if the stiffness was achieved because

1) the pivoting frame that actuates the shock absorber is positioned across the vehicle, attached to both sides of the frame

2) the two lower control arms are tied together through the linkage.

He explained that the stiffness is a result of the fact that the two lower control arms are linked together. During normal cornering the outside suspension goes into compression and the inside suspension goes into rebound. Linking the two sides together through the shock frame forces the wheels to move together and that resists body roll. The stiffness of the shock frame is also a factor and lengthening the shock frame to fit the wider chassis will likely require some stiffening of the shock frame to resist torsional distortion during cornering. He also mentioned that he originally thought he had invented a unique suspension system but later discovered that some European race cars had also done the same thing.

He also mentioned that the chassis on a three wheeled vehicle does not need to be as stiff as on a four wheel vehicle because all weight transfer during cornering happens only at the front rather than front to back as in a four wheeler.

We also discussed the concern of CG location in a side-by-side arrangement and the asymmetrical CG position caused by a single occupant, resulting in reduced roll over limits. I mentioned that I plan to move the passengers forward a bit to improve CG. He also thought that a two seater would be better received in the market than a single seat. While marketing the resultant vehicle from this effort is in the back of my mind, my primary objective is to complete one for the fun of the project and to enjoy driving a vehicle I have designed and built. Whatever will be will be.