Wheel backspacing and wheel offset

[Lengele103]

I have a 1975 with a 2 1/2 inch lift, and. 1 inch body lift, TBP front disc brake kit.

My issues is with finding some wheels that I like to fit. I have found some Ultra 178s in the 17 inch rim, they have a 5.5 backspace with a 20 mm offset, but they touch the rear shocks.

Anyone have any advice about 17 inch rims, from like moto metal, xd or fuel? I have found some moto metal wheels that have a 17x8 rim with 4.5 in backspace and no offset, or a 17x9 inch rim with -12mm offset. Dont know if these would have the same issue or not?

Any advice or info would be helpful. Maybe just have to relocate the stock rear shocks?

I have pictures on my phone but dont know how to get them here...

 

[duffymahoney]

You can weld new shock mounts in a 1/2"-1" or do what some rear disk brake conversions make you do. Which is fill the stock mount with a bushing, then a long bolt though and run the shock on the outside of the stock mount. Picture attached to help.

 

[duffymahoney]

Another closer picture. Terrible quality though

 

[Lengele103]

Thanks, this is what I was thinking of doing, but what about the wierd angle in the top mount of the shock. Wont this cause some binding in the top bushing?

 

[Apogee]

Wheel backspacing and wheel offset are the same thing, just measured from difference reference points. BS is the distance from the wheel mounting surface/pad to the inner lip, whereas offset is the distance to the theoretical centerline of the wheel, with positive offset dimensions pushing the pad outside the centerline and negative offsets moving the mounting pad inside the centerline.

That said, you can always space a wheel out, but you can't space them in any, so better to err towards too much BS or (+) offset in most cases.

 

[Bronc937]

I don't know if this helps, but here are 17x8 with 285/70's 4.5 backspace and 0 offset, uncut with 3.5" SL and 1" BL. Shocks mounted in stock location. The picture doesn't show it really well but I have about 2 inches of clearance between the shock and tire.

Sent from my iPhone using Tapatalk

 

[duffymahoney]

I don't know if this helps, but here are 17x8 with 285/70's 4.5 backspace and 0 offset, uncut with 3.5" SL and 1" BL. Shocks mounted in stock location. The picture doesn't show it really well but I have about 2 inches of clearance between the shock and tire.

Sent from my iPhone using Tapatalk

I have no idea how you clear those 285s so well! Nicely done.