Wheel backspacing / ET measuring.

Wheel backspacing / ET measuring.

Author
Discussion

melhookv12

Original Poster:

958 posts

173 months

Thursday 28th May 2020
quotequote all
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

21,886 posts

157 months

Friday 29th May 2020
quotequote all
Larger et means wheel is further inside the arch. Sounds right to me.

stevieturbo

17,229 posts

246 months

Friday 29th May 2020
quotequote all
https://www.willtheyfit.com/


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

melhookv12

Original Poster:

958 posts

173 months

Friday 29th May 2020
quotequote all
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

745 posts

180 months

Friday 29th May 2020
quotequote all
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 laugh)

melhookv12

Original Poster:

958 posts

173 months

Friday 29th May 2020
quotequote all
Your figures make more sense but i keep getting






Peter3442

418 posts

67 months

Sunday 14th June 2020
quotequote all
Difference between total wheel width and rim width.