Stock Backspacing

heff · April 18, 2008

does anyone know the stock backspacing for the nbs sierra sle1 2wd

fiero2m4 · April 18, 2008

does anyone know the stock backspacing for the nbs sierra sle1 2wd

First - no I do not know an answer for you. Sorry. But do you need it for a stock 17x7.5 wheel or was another width available? Was the 20" a 20x8? Backspacing (& offset) could vary based on what size wheel you want specs for.

But on a related note --- why do most truck people want to know backspacing specs while most car guys need offset? (I DO know what each are on a wheel how and how they are related) --- but why the need to maintain specs on both?

hubbycap · April 18, 2008

does anyone know the stock backspacing for the nbs sierra sle1 2wd

First - no I do not know an answer for you. Sorry. But do you need it for a stock 17x7.5 wheel or was another width available? Was the 20" a 20x8? Backspacing (& offset) could vary based on what size wheel you want specs for.

But on a related note --- why do most truck people want to know backspacing specs while most car guys need offset? (I DO know what each are on a wheel how and how they are related) --- but why the need to maintain specs on both?

Generally the OEM spec is expressed in offset and aftermarket wheels are shown either offset of backspace. Backspace is most often used when describing very wide wheels. Here is a good explanation of offset:

Offset Explanation

Backspace is the distance from the mounting hub and the plane of the back flange and is shown in inches. Offset is the distance from the over width the centerline of the wheel lies expressed in mm (generally.)

Offset of a reasonable width OEM wheel is convertable to backspace and that measurement can be applied to a much wider aftermarket wheel with some level of assurance that the wheel will not rub the frame if turned sharply. There is no level of assurance however that the ride or handling will no be effected adversly.

Zembonez · April 18, 2008

But on a related note --- why do most truck people want to know backspacing specs while most car guys need offset? (I DO know what each are on a wheel how and how they are related) --- but why the need to maintain specs on both?

Offset and backspacing are two totally different things. Backspace is distance from the hub to the back edge of the wheel and offset is simply a measurement of the hub mounting surfaces variation from wheel center. Both can be used for wheel fitment IF you have some other data.

Custom truck wheels are often much wider than stock and backspacing becomes an issue for brake and suspension clearance issues. Offset is really only a valid measurement for wheel comparison if the two wheels are the same width.