rim/wheel help

[t_g_farrell]

I know this has been discussed on the "other" site but I don't know the answer off hand.

[ran83]

I appreciate it gentlemen.... If you have any information I am willing to take it in.

[GySgtFrank]

Originally Posted by ran83

I appreciate it gentlemen.... If you have any information I am willing to take it in.

This question is so dependent on wheel/tire diameter and width that it is impossible to give you an answer that wouldn't be likely to leave you buying something that wouldn't work. The best bet is to measure what you have and do the calculations yourself to get what you actually need instead of a generalized answer. If you need to push the wheel out add offset and vice versa. (measure width at the sidewall "bulge") An inch equals 25.4 mm which is what most offset is figured in.

Your existing wheels should be marked with the offset, but if they're not you can use straight edges across the wheel to measure from the inside wheel mounting surface to the tire bead and the width of the wheel. (the bead lip isn't included in normal width figures) With the mounting surface dead center of the wheel you have a zero offset wheel. Outward of center is positive offset, (most common) and inward is negative offset.

On a side note the closer to zero your offset is, the less strain you will have on your wheels and bearings while cornering. Hope that is helpful.

[RETed]

Originally Posted by GySgtFrank

On a side note the closer to zero your offset is, the less strain you will have on your wheels and bearings while cornering. Hope that is helpful.

Not quite true...

The more positive the offset, the less strain on your bearings...
Mazda has been doing it with the RX-7's with the FD being the pinnacle of that theory.
The FD runs an 8", +50.
(FC turbo runs a 7", +40.)
In fact, take a look at all the well-known sports cars that are still running OEM wheels - especially the fronts.
Big (positive) offsets are not the prettiest to look at - if you like DEEP DISH - but the positive offsets have performance advantages.

If you run the wheel face as far outward as possible, the induces the forces from the rubber gripping the road to a more perpendicular vector in relation to the wheel bearing - i.e. radially.

Move that offset inward, or towards "0" or negative, this force starts going diagonally through the wheel bearing.
This is actually what prematurely kills wheel bearings, if they are not designed to handle such force vectors outside of stock specs.


-Ted