Wheel backspacing / ET measuring.

[melhookv12]

I wonder if someone can help.

11 inch rim. 6 inch back space.
Using a calculator it says that my ET is 0.
11 inch rim, 5.5 inch back space ET12.7.

Does this sound right. I would have thought it would be the other way around.


Thanks for any replies

[Scrump]

Larger et means wheel is further inside the arch. Sounds right to me.

[irocfan]

https://www.tyresizecalculator.com/tyre-wheel-calc...

[stevieturbo]

https://www.willtheyfit.com/


backspacing is a yank term...it's a bit weird.

[melhookv12]

The bit thats confusing me is if the backspace was half the width, 5.5 inch of 11, then i would of thought it to be neutral, as its centre.

But using the calculators 5.5 back space comes out at 12.7mm ( 1/2 inch )

6 inch backspace comes in at 0 ET.

I have measured backspace of know wheel with known ET. The calculator works correctly.

Im just a bit stumped by the maths.

[ndtman]

Just tried the calculator linked by irocfan using your dimensions and I get ..

Be sure to use measured values i.e. distance between inner lips of the rim (ooh matron )

[melhookv12]

Your figures make more sense but i keep getting

[Peter3442]

Difference between total wheel width and rim width.