Production design— With a kingpin inclination angle of 12.2&#deg; and a rim offset of 12 mm (0.47 in.), the resulting scrub radius at a 358 mm (14.1 in.) static loaded radius (SLR) is 54.8 mm (2.16 in.). The geometric distance from the constant velocity (CV) joint centerline to the rim centerline is 132.4 mm (5.21 in.). The CV joint shaft has a spline that directly connects it to drive the wheel hub. A conventional threaded nut retains the hub, wheel bearing, and the CV shaft.

This SLA suspension design features a conventional CV joint on the wheel driving shaft. The SUV is designed for rear drive with a 4WD option. The integral hub and bearing unit shown features a self-contained ABS sensor and tone wheel. The lower ball joint installed in the lower control arm (not shown) is loaded in compression. The upper ball joint is included with the upper control arm (not shown).

CV Hub advanced design—The scrub radius was reduced to negative 20.2 mm (-0.80 in.). Alternate rim changes allowed scrub radius settings of negative 9.8 mm (-0.39 in.), and positive 24.9 mm (0.98 in.).

A negative scrub radius was accomplished by combining the wheel hub or spindle with the CV joint into a single component. This CV Hub configuration allows the packaging for the combined components to reduce the geometric distance between the joint centerline and rim centerline to just 60.9 mm (2.40 in.), as opposed to the original configuration of 132.4 mm (5.21 in.).

The kingpin angle was increased to 12.7&#deg;, primarily to maintain similar handling characteristics. The upper and lower SLA control arms were also repositioned and their lengths adjusted to maintain the handling characteristics of the original production vehicle. The ball joints are positioned to allow a carryover brake rotor diameter.

Vehicle modifications—To incorporate the CV Hub into the test vehicle, it was necessary to change existing suspension components. The CV Hub was incorporated to allow changing the scrub radius while maintaining alignment angles and production tread width.

Included within the CV Hub design was a custom knuckle that relocated both upper and lower ball joint centers. To include the new ball joint centers in the existing vehicle, lower control arms were modified by extending them outboard. New upper control arms were made, and the front and rear upper control arm bushing centers were relocated downward and outboard via extension brackets. Tie rods for both sides were lengthened and connected to the CV Hub knuckle.