jkmhb

I got rid of my aftermarket dual bolt pattern rally wheels (they would actually flex in the center when you bolted them on - a very strange design). They were 15X6 with a 4" backspace. The rears would barely (within 1/16") clear the emergency brake clip on the trailing arm. I plan to get the Pirelli P4000 215-70X15 tires.

What was the backspace of the factory 15X6 rally? Anyone have feedback on the Wheel Vintiques series 30 rally?

THX.

SWCDuke

Offset of the OE 6" Rally Wheels is +0.060". [edited to correct value]

Duke


[Modified by SWCDuke, 9:48 PM 2/10/2004]

waynec

From notes I've made from past posts on various forums, the backspace for the 67 Corvette 6x15 "DC" rally is 3.56 inches. That should give you a bit more clearance.

The 6x15 "FW" rally (Camaro?) is 3.8 inches.

grumpy55

SWCDuke,
Should that be 0.06" (not 0.60") ?

JohnZ

It's +.060" (sixty thousandths). :thumbs:

66427-450

my notes say that FW is a "7" inch rally, with a +.3 offest (camaro/monte). and I agree +.06 for the '67 6" wheel.

jkmhb

So - what is the relationship between backspace and offset? Should you be able to calculate one, given the other?

Paul L

*Deleted*-A misleading link to offset/backspacing was provided by me. My apologies to Members.


[Modified by paul67, 2:40 PM 2/10/2004]

JohnZ

Very nice explanation and graphics, but they're wrong - they have it backwards. There is not, and never has been, any disagreement in the OEM community about the definition of positive-vs.-negative offset; note their words at the end - "that's the way we do it".

The OEM definition of offset hasn't changed in over 80 years. If the wheel bolt-up face is outboard of the centerline of the rim, that's positive offset; if the bolt-up face is inboard of the centerline of the rim, that's negative offset.

A much better reference for wheels is at:
http://www.rsracing.com/tech-wheel.html

:cheers:

Paul L

I will remove the bad link/reference.