The Dark Side of Will wrote:The C5 ZO6 wheel has 11 13/32 outside width with 8 1/32 outside backspacing
Therefor the offset is <scribble> 2 21/64 or 59.13mm. If I squint a little bit, that looks like the 58mm spec I've seen on the interwebnets.
The base C5 wheel measures 10 1/16 outside width and 7 7/16 outside backspacing. That is to the "face" on each side, just radially in from the lip representing the extreme dimension. I had to use that measurement because both of my base C5 wheels currently have tires on them.
That calculates to 2 13/32 or 61.12mm of offset.
That's weird because most of the internet says 65mm, while Skulte--who ought to F#$%ing know--says 63mm. ( http://www.skulte.com/adapterfaq.html
). With the result being off by either 2 or 4 mm, that means a measurement was off by 4 or 8mm.
However, Skulte's main site is down, so they may be out of business.
The outer lip on these wheels is oddly profiled and may have skewed my measurement. I can believe the geometry of the puts my width measurement high by as much as 4mm, which would then put my offset calculated from measurements at 63mm.
I can't believe that the lip geometry makes my overall width measurement 8mm high, which would be what was required to put my calculated offset 4mm high.
But if 63mm is the right number, then most sources on the internet are wrong. This wouldn't be the first time--not even the first time in this thread!--but would be mildly surprising.