Author Topic: Wheel backspace and size  (Read 1376 times)

Offline bigblockchevelleman

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Wheel backspace and size
« on: December 30, 2022, 03:22:53 PM »
First off I would like to say thank you for the help Steve  ,I'm in the final stages of a complete rebuild and a two year job with having suffered health issues and loss of family members Thank you everyone who has helped me  . Ok my question I'm trying to figure backspace  , offset of wheels so that no spacer is required I've lowered the truck slightly with shackles and hangers in the rear and drop spindles using in the front  , wanting to go with either 17,18 Not crazy about 20s I like the American racing salt flats  THANKS for any help Steve

Offline JohnnyPopper

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Re: Wheel backspace and size
« Reply #1 on: December 30, 2022, 09:18:43 PM »
First, I'm not Steve, or Lisa... 8)

You have to start with the basics of what you have to work with.

Enclosed is a diagram of such.

Disclaimer to those who flame- pls let's all go lay down by our bowl.

FYI Front will differ from rear fender well due to turning radius but same principles apply from a baseline measurment of A, B, C, and D.

With the same measuring points you can get the data you need.

Your NEXT task is to get measurements from the wheels/tires you desire AND measure those against the space/travel you have.

It's easier than you think! You got this man!!!
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Offline Scott91370

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Re: Wheel backspace and size
« Reply #2 on: January 03, 2023, 04:38:57 PM »
I'm running the US Mags Rambler with a 4" back space (or 1mm offset) and a 245/45-17 tire. Tons of room and I have 2.5" spindles and 2" springs.
I also have a 1.5" or 2" spacer to bring the wheels out and I do not have any rubbing issues.
So essentially I could run a 1.5" back space (40mm offset) to get the same position with these tires and have no problems.

Remember, it's not just the size of the wheel but height/width of the tire.

Offline 87ChevyR10

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Re: Wheel backspace and size
« Reply #3 on: October 27, 2023, 04:59:11 PM »
that handwritten diagram was more useful to me than 20 posts beating around the bush about across search results.

almost a year later its appreciated as tires, rims and figuring out backspacing/offset for my 87 is also underway

Offline JohnnyPopper

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Re: Wheel backspace and size
« Reply #4 on: October 27, 2023, 08:32:06 PM »
Thanks!  ;D

Glad I could help.
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction