I still don't completely get offset calculations and it's very frustrating. I understand what an offset measurement is... And I have seen and attempted to use offset calculators like this one...

http://www.1010tires.com/WheelOffsetCalculator.asp

But the theory is throwing me off. It would seem that the wider the wheel, the lower offsets (closer to zero or negative) you could pull off. So in order to clear my Brembos, I could either get very conservative offsets (+30) or get a wider wheel and get more aggressive offsets (+22). Is my logic correct and if not does anyone know a good comprehensive resource to do some reading up on this?

**Flamesuit on**

 

Your logic is correct. Remember that clearing the brake calliper is not only a function of offset but spoke design. The key is for the tire to clear the strut. If you are considering 8 or 9 inch wheels, you have a lot of room to play. If you are considering 10 inch plus wheels then offset is critical.

 

Both width and offset play a part. For example, a 8" +30 stock wheel. If you were to replace it with a 10" +30 wheel the offset is the same. However, since the wheel is 2" wider it would extend 1" further out and use 1" extra on the suspension side as well, basically splitting the difference.

So really the narrower wheel can pull off lower offsets. A 8" +0 is very close to a 10" +25. The best way to get an idea what fits nicely is to see what others are running. Since there is so much fender room, most people run wider wheels and lower offsets. Hopefully this made some sense.

 

Thanks it does make sense... Except for terminology:
Lower offset meand closer to zero or neg. right?
More aggressive generally refers to closer to zero or neg?

 

yes and yes. When people say aggressive they are typically referring to the +10 thru +17(getting closer to zero or negative) with these offsets and the pretty standard of 10.5 inch wide wheels in the back, fender rolling is a must.