Quote:
Originally Posted by dmboone25
Damn. Not very wide then....
I’ve never been able to understand how the tire sizes work - maybe a wider tire would work. These would look great on the F87.  |
It can be very confusing and is why there's a whole industry helping people fit wheels. Not sure what you know or don't know, but here are the basics.
Rim width governs how wide a tire you can fit without it being stretched, usually 1.5". For example, if your tire is 225mm wide it'll fit on a rim that's 7.5-9".
Offset determines where the wheel sits on the hub, either recessed in such as the stock setup, hellaflush, wheel poke, etc. This is what confuses most. Positive offset actually means the wheel is recessed in further.
Example, a rim that is 10" wide will have it's center line at 5". The offset is where the wheel mounts in relation to the center line. So if the wheel has a +40mm offset, the wheel hub will be "offset" +40mm from the wheels center line which recesses the wheel further into the wheel well. A negative offset does just the opposite, pushes the wheel out more. You'll rarely see negative offsets, most are positive, but playing with that will determine where the wheel sits. Rule of thumb, the higher the offset numer the more the wheel is recessed in, the lower the more the wheel is pushed out.
Offset example (each dash is 1")
An offset of 0 on 10" wheel would be right in the middle at 5" -----|-----
An offset of +40mm on 10" wheel would sit +40mm off center ---|------
There are all sorts of other factors come into play such as lowering a car and getting the right offset without rubbing the fender/quarter panel, being able to turn the steering wheel from left to right lock without rubbing inside the wheel well, clearing brake calipers, clearing suspension components, etc.
Clear as mud?
