Suggested ideal backspacing for a wheel (1 Viewer)

r2m

Richard
Joined
Nov 1, 2007
Messages
2,422
Location
San Clemente, CA
 
 
I'm going to have to get rid of those blinging 20" wheels that came with my 98 LC and am looking at either a 16" or 17" wheel to mount a 35" (315/75") tire.
Serveral things I'm considering:
- 16" wheel cause tires are cheeper
- 17" wheel cause more tire choices and cheeper than any size larger than 17" in diameter.

My question is: what would be the ideal backspacing for a rim?
Factory backspacing for the 16" x 8" rim is 60mm. I'm trying to stay as narrow as possible in rim width, say, 7" to 8", and trying to avoid going to a 9" width. My thought is that a narrow rim with, 8" like factory, with a 40mm or 50mm backspacing would move my tire one inch out, towards the fender, meaning a wider track. Which would help in not rubbing in lock-to-lock steering, etc. I know people add spacers to their wheels, which I think are any where from 1" to about 1.5". But I want to avoid spacers and just get wheels already offset.

Perhaps the better question to ask is what would be the ideal depth from the inside rim width to the bolt flange on the wheel?

Thanks Mudders!
 
Last edited:

uHu

Bridgeburner
Joined
Nov 27, 2005
Messages
2,031
Location
Oslo, Norway
 
 
This is not really my field, but here is something to consider as a start. Someone with more knowledge in steering geometry might chime in....
(and, IIRC, there are already threads covering this subject in here)

Anyhow, the selection of rims for the 100 is very limited, so you won't have many choices.

If you want to preserve drivability, and avoid power-steer and tracking problems, one important factor is that the line through the (imaginary) King Pin and the line through the center of the wheel have to meet the road surface at a certain distance. So, if you know the king pin inclination (or Steering Axis Inclination), you can calculate the extra spacer you need when going from 31" (stndrd) to e.g. 33".

Se the illustration as an example. If you increase the tire diameter, the distance between the two lines will decrease, or even become negative. That can be rectified by moving the wheel further out. (which again will lead to increased wear on steering components)
steering_axis.gif
 
Joined
Apr 28, 2010
Messages
2,399
Location
Atlanta, GA
 
 
Just get the 16 inch OEM ones and be done with it. They look good, they are cheap, they pop up in the Classifieds all the time, and often you get a great set of tires thrown in for very little extra.

I personally think that the 100 is one of those few vehicles that only looks its best with OEM or Tundra wheels.
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top Bottom