<VV> Backspacing

[Padgett]

>If someone could explain exactly how backspacing measuring works it would 
>probably help me a great deal.  Is it the distance from the inner mounting 
>surface to the inner edge of the wheel in inches?

Dunno if the right way but I turn the wheel over so the backside it up, lay 
a piece of wood across the inside of the rim (not the lip) and measure the 
distance to a hub mounting flat (usually next to a lug hole). The 13x5.5 
stock steel wheel acting as my spare measures right on 4". Less means the 
wheel extends further out . Think my 14x6" wheels were about 3.75" which 
accounts for the close encounters at one turn from straight ahead of the 
steering wheel of the 195x70x14s I have on the front.

Offset OTOH is the distance from the hub mounting face to the centerline of 
the wheel and is usually measured in mm. If the backspacing stays the same, 
the offset will change as the rim width increases and verse da vice.

Padgett