Just like the title says, I really don't know technically what higher and lower offsets will do for you. Thanks!

 

you mean wheels YO??!!

 

gawd

 

the offset is the distance of the hub mounting surface from the centerline of the wheel. Usually measured in MM. A +38mm offset would mean the hub mating surface of the wheel is 38mm from the centerline of whe wheel. A lower (numerically) offset will push the wheel 'further' away from the hub, while a higher (numerically) offset will bring it in 'closer' to the hub.

Make sense?

RJ

 

offset is the distance from the centerline of the wheel to the mounting surface.

 

So higher and lower merely alter how wide your track (width wheel to wheel) is?


[Modified by JMU1337, 3:23 PM 7/9/2002]

 

Keep in mind that it is also very important for things like whether you would rub on the fender, the springs, or neither. That's where it becomes important.

 

Basically. And for clearance with things like your suspension, fenders, etc, etc.

 

Offsets have to do with how far (or not) the lug holes/attachment area of the wheel is from the exact center of the wheel width. It's easier to explain with picture, which I'll try below.

Assume you have a 6" wide wheel, if this wheel has a "0" offset, then the lug holes would be exactly in the middle of the wheel width, 3" from the inside and outside, as below.

6" wheel
outside inside (toward brake rotor)
-----------
|
|
|
|
-----------

A wheel with a positive offset has the center line of the wheel moving toward the outside of the car, essentially moving more of the wheel toward the brake rotor, as below.


6" wheel
outside inside (toward brake rotor)
-----------
|
|
|
|
-----------

Similarly, a negative offset has the center line of the wheel moving toward the inside of the center line, moving more of the wheel to the outside of the car, as below.


6" wheel
outside inside (toward brake rotor)
-----------
|
|
|
|
-----------

Offsets are all about clearance issues (from the brake caliper and the fender lip) for whatever car you drive, and become very important when going to a wider than stock wheel width. If this ain't clear, maybe someone else here can explain it better. HTH.

edit: damn drawings didn't work! the center line/wheel attachment lines in all three drawing somehow got left justified when posted, but looked great in the "post reply" box. chit!



[Modified by Neo, 10:31 AM 7/9/2002]

 

You'll also hear the term "Backspace" used, mostly from us oldtimers.

Goggle popped this up as the first response to "wheel backspace", but it covers offset too.

http://www.rsracing.com/tech-wheel.html#backspace

The "Backspace to Offset conversion chart" alone is worth the trip.



[Modified by Geezer, 10:35 AM 7/9/2002]

 

And it includes this drawing:

 

Ok ok I understand it all now. Why worry about offsets (get the lowest) when you can use spacers? Don't the spacers do the same basic thing?


[Modified by JMU1337, 3:39 PM 7/9/2002]

 

Great pic! Much better than my "hand drawn" ones...

 

1. Spacers get lost at the worst times.

2. Spacers add unsprung weight.

3. Spacers require longer lugs.

4. Unless properly designed, spacers don't provide as much support for your wheel as the hub does.

 

I prefer backspace, easier to picture and less likely to get it backwards, since it can only positive.

 

i think of it this way. higher number tucks it into the wheel well more, lower number pushes it out. It was said already pretty much but thinking of it this way simplifies it the most for me.

s

 

looks good

 

The more spacers you use. The more leverage you are placing on the bearings (in the hubs) creating unwanted strain to the bearing. Bearings are designed to work with no spacers the less spacers you use the better.
Hope this helps

 

Some other factors to consider. Changing offset or back spacing will also change your roll stiffness on both front and rear axles. And will change your scrub radius on the front axle.

 

Yes, scrub radius is a big issue when talking about offset. In the front only though. Think about how the each wheel turns when you steer and how offset from the pivot point of this steering motion will affect it.