offset
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Sr20detNESS
- Posts: 82
- Joined: Mon Aug 01, 2005 3:26 am
- Car: '92 240sx fastback redtop sr20det
Re: offset (Sr20detNESS)
Of set is the amount the center of the wheel is offset from the hub.This changes how "sunken" the wheel looks. It also affects the track width of your car, and the forces applied to the hub. the lower the offset (mounting point moving inward, or rim moving outward) the more leverage acting on your wheel bearing. Offset also tries to steer the wheel putting tension on the steering linkages to eliminate free play, as well as helping maintain stability in case of a blow out.
Looking at the wheel from straight ahead and drawing a vertical line through the mounting point on the rim we get the steering axis, when the wheel turns it rotates around this line (in real life its not gonna be right at the mounting point for the hub, but we'll ignore that for simplicity's sake). If we place the tire so that from view of the treads we have an equal amount on both sides as it rolls down the road the drag of the tire will pull equally on both sides of the steering axis canceling each other out. If the tire is placed with slightly more tread on one side or the other, there will be more pull on that side from the drag of the tire and the wheel will want to turn in that direction. In real life the steering axis us from the upper mounting point of the strut to the ball joint on the control arm, so instead of 0 offset placing the tire equally on both sides some negative offset is needed. Manufacturers will generally use something just slightly off of being centered on the steering axis for the reasons I mentioned earlier.
Looking at the wheel from straight ahead and drawing a vertical line through the mounting point on the rim we get the steering axis, when the wheel turns it rotates around this line (in real life its not gonna be right at the mounting point for the hub, but we'll ignore that for simplicity's sake). If we place the tire so that from view of the treads we have an equal amount on both sides as it rolls down the road the drag of the tire will pull equally on both sides of the steering axis canceling each other out. If the tire is placed with slightly more tread on one side or the other, there will be more pull on that side from the drag of the tire and the wheel will want to turn in that direction. In real life the steering axis us from the upper mounting point of the strut to the ball joint on the control arm, so instead of 0 offset placing the tire equally on both sides some negative offset is needed. Manufacturers will generally use something just slightly off of being centered on the steering axis for the reasons I mentioned earlier.
