offset versus scrub radius Options

[r_towle]

Does it make a difference what the offset is on a wheel with regards to scrub radius?

It does not seem that it would, given the stock suspension, no custom struts etc.

Aside from that, what is the reason (aside from cost and availability) for using large spacers versus getting wheels that mount up with no spacer, yet are wide for flared cars?

rich

[J P Stein]

The following sketch does not represent all of the aspects of SR vs its effects....but the best I got.
It does show the method of measuring SR and one fella's attempt to fix it thru camber changes

An increase in SR does indeed effect the car & handling, basically one increases the leverarm of the axle against rotation....leading to increased steering effort....that's the easy part to figure out.

The increase also puts the CL of the tire/wheel farther fom the center of rotation.This gets this center "out ahead"of the rotation when turning....not a problem for minor (say 5-10 deg) steering inputs. Major inputs , such as found at AX, are another story. These will cause the tire to "shuffle" sideways rather than roll. ....been down this road with 10 inch wide front wheels...giving me about 2.5+ inches of SR.....resulting in an increable PUSH.

Fixed it with 8 inch wide wheels but with only a .5 inch loss in tire width.

[Randal]

The following sketch does not represent all of the aspects of SR vs its effects....but the best I got.
It does show the method of measuring SR and one fella's attempt to fix it thru camber changes

An increase in SR does indeed effect the car & handling, basically one increases the leverarm of the axle against rotation....leading to increased steering effort....that's the easy part to figure out.

The increase also puts the CL of the tire/wheel farther fom the center of rotation.This gets this center "out ahead"of the rotation when turning....not a problem for minor (say 5-10 deg) steering inputs. Major inputs , such as found at AX, are another story. These will cause the tire to "shuffle" sideways rather than roll. ....been down this road with 10 inch wide front wheels...giving me about 2.5+ inches of SR.....resulting in an increable PUSH.

Fixed it with 8 inch wide wheels but with only a .5 inch loss in tire width.

I listened to what you said JP and reduced my tire size to a little over 8" with 5" offset. Hard to believe but I've experienced no under steer since. The Avon tires could have helped, but honestly I haven't found the limit on corners yet.

Probably should go out and just push the hell out of the car until I find the limit, but those Avons are expensive; meat grinding them just isn't on.