CCW owners look plz!

[atdeneve]

I'm sorry, but what you're saying just doesn't make sense.

Yes, any custom wheel manufacturer has their own offset for each vehicle as determined by their engineers. In other words, they take the measurements on stock vehicles and determine what fits.

And yes, if one were so inclined, they will allow you to specify your own offset, however, they make it plenty clear that they will then not guarantee fitment.

For someone to arbitrarily use the offset from one specific wheel model for a different wheel model, even if it is from the same manufacturer, nevermind another brand, would be just that, arbitrary. And haphazard. Any and all manufacturers will provide due warning that that may very well bring with it serious fitment issues.

So, A) who the hell is going to try and use offsets from a wheel of one manufacturer and apply them to wheels from another manufacturer and B) if there exists such an idiot, what manufacturer is going to accept those offsets without emphasizing the fact that fitment can and very well may be an issue? There is no liability here.

Simple and plain, there is no reason why such information would be or can be considered proprietary. Nada. Nunca.

[MSOsr]

Originally Posted by atdeneve

I'm sorry, but what you're saying just doesn't make sense.

Yes, any custom wheel manufacturer has their own offset for each vehicle as determined by their engineers. In other words, they take the measurements on stock vehicles and determine what fits.

And yes, if one were so inclined, they will allow you to specify your own offset, however, they make it plenty clear that they will then not guarantee fitment.

For someone to arbitrarily use the offset from one specific wheel model for a different wheel model, even if it is from the same manufacturer, nevermind another brand, would be just that, arbitrary. And haphazard. Any and all manufacturers will provide due warning that that may very well bring with it serious fitment issues.

So, A) who the hell is going to try and use offsets from a wheel of one manufacturer and apply them to wheels from another manufacturer and B) if there exists such an idiot, what manufacturer is going to accept those offsets without emphasizing the fact that fitment can and very well may be an issue? There is no liability here.

Simple and plain, there is no reason why such information would be or can be considered proprietary. Nada. Nunca.

Look at any car website.....people talk about what offset worked for them all the time. OTHER people (stupid, of course) order the same offset on their wheels, and they don't fit.

Are most jurors savvy about offsets? No. Why have to argue to a jury that Buyer A should have known that "our +25 offset that we advertised as fitting CTS-Vs wouldn't apply across the board to any wheel he ordered"? Why not just keep your offset to yourself and guarantee your customer that the wheels will be appropriate to his car?

I think most people would prefer having the manufacturer guarantee the fitment, rather than guarantee the offset number. I would certainly advise my client not to throw out fitment numbers to the great unwashed.

Mike (Even if you're right, you can still be sued ... and lose)

[AAIIIC]

Originally Posted by atdeneve

I'm sorry, but what you're saying just doesn't make sense.

Yes, any custom wheel manufacturer has their own offset for each vehicle as determined by their engineers. In other words, they take the measurements on stock vehicles and determine what fits.

And yes, if one were so inclined, they will allow you to specify your own offset, however, they make it plenty clear that they will then not guarantee fitment.

For someone to arbitrarily use the offset from one specific wheel model for a different wheel model, even if it is from the same manufacturer, nevermind another brand, would be just that, arbitrary. And haphazard. Any and all manufacturers will provide due warning that that may very well bring with it serious fitment issues.

So, A) who the hell is going to try and use offsets from a wheel of one manufacturer and apply them to wheels from another manufacturer and B) if there exists such an idiot, what manufacturer is going to accept those offsets without emphasizing the fact that fitment can and very well may be an issue?

OK, I'm that idiot. You guys will have to explain to me why (just making up numbers here) an 18x9" +38mm wheel from HRE would fit and an 18x9" +38mm wheel from iForged or Kinesis or anyone else would not fit. Offset is used by wheel manufacturers because it is a standardized measurement - if I know the wheel offset and the wheel width, I know where the wheel is going to sit in the wheel well. If my hypothetical HRE wheel from above doesn't cause the tire to rub the fender lip or the wheel to rub the trailing arm or anything like that, then one from another manufacturer shouldn't, either.

The only possible issue from wheel to wheel would be brake clearance, but that has more to do with spoke design than it does with offset. If someone buys the wrong wheel, it contacts the caliper, and they blame that on the wheel offset then yes, I agree, they're an idiot. My other two cars are a Subaru and a Mustang. On the Subaru forums it's a well-known fact that some wheels that fit the WRX (and all the rest of the non-STI cars) won't fit the STI because of it's big Brembos. All the Imprezas and Legacys use the exact same offsets, you just have to ensure the spoke design will clear the Brembos. Similarly, on the Mustang forum it's a well-known fact that some wheels won't clear the 2000 Cobra R Brembos (which a lot of open track types upgrade to). Again, the offsets are exactly the same, it's just the face design of the wheel that matters.

Everyone here knows (or should know) that the CTS-V has big frickin' brakes. If they order wheels using another manufacturer's offset and don't ask about caliper clearance, well, they're an idiot.

Originally Posted by MSOsr

Look at any car website.....people talk about what offset worked for them all the time. OTHER people (stupid, of course) order the same offset on their wheels, and they don't fit.

Other than caliper clearance I'd love to see an example of this.

Originally Posted by MSOsr

Are most jurors savvy about offsets? No. Why have to argue to a jury that Buyer A should have known that "our +25 offset that we advertised as fitting CTS-Vs wouldn't apply across the board to any wheel he ordered"? Why not just keep your offset to yourself and guarantee your customer that the wheels will be appropriate to his car?

I think most people would prefer having the manufacturer guarantee the fitment, rather than guarantee the offset number. I would certainly advise my client not to throw out fitment numbers to the great unwashed.

Mike (Even if you're right, you can still be sued ... and lose)

Ohhh, God, make the needless lawyer talk stop!!

[lunarx]

Originally Posted by AAIIIC

OK, I'm that idiot. You guys will have to explain to me why (just making up numbers here) an 18x9" +38mm wheel from HRE would fit and an 18x9" +38mm wheel from iForged or Kinesis or anyone else would not fit. Offset is used by wheel manufacturers because it is a standardized measurement - if I know the wheel offset and the wheel width, I know where the wheel is going to sit in the wheel well. If my hypothetical HRE wheel from above doesn't cause the tire to rub the fender lip or the wheel to rub the trailing arm or anything like that, then one from another manufacturer shouldn't, either.

The only possible issue from wheel to wheel would be brake clearance, but that has more to do with spoke design than it does with offset. If someone buys the wrong wheel, it contacts the caliper, and they blame that on the wheel offset then yes, I agree, they're an idiot. My other two cars are a Subaru and a Mustang. On the Subaru forums it's a well-known fact that some wheels that fit the WRX (and all the rest of the non-STI cars) won't fit the STI because of it's big Brembos. All the Imprezas and Legacys use the exact same offsets, you just have to ensure the spoke design will clear the Brembos. Similarly, on the Mustang forum it's a well-known fact that some wheels won't clear the 2000 Cobra R Brembos (which a lot of open track types upgrade to). Again, the offsets are exactly the same, it's just the face design of the wheel that matters.

Everyone here knows (or should know) that the CTS-V has big frickin' brakes. If they order wheels using another manufacturer's offset and don't ask about caliper clearance, well, they're an idiot.


Other than caliper clearance I'd love to see an example of this.


Ohhh, God, make the needless lawyer talk stop!!

You are right for the most part.

However, I suspect that wheel width is loosely defined.
For instance a 9" wheel from one manufacturer could be slightly wider than a 9" wheel made by another manufacturer.
Since not many people would complain if their wheel was 9-1/8" instead of 9" they probably don't bother disclosing any slight variances there.

For instance, , in the case of a wheel hitting the trailing arm, some other wheel factors like barrel ID and rim thickness come into play.

Since the wheel with is the inside rim distance from tire bead to tire bead it does not specify the true overall width of the wheel to its outer edges.

If one wheel manufacturer had a lot of extra material added at the inside rim edges, that could result in trailing arm contact with one wheel but not another.

Both wheels could literally have the same offset and width (tire bead-tire bead).

Even so, offset is still a very usefull spec to have available to you.
It will give you an idea as to which end of your wheel will have fit issues.
Just verify the true wheel width, as I still suspect there could be some variations there (especially in the case of 3 piece wheels).
I think manufacturers just round off to the nearest 1/2 inch.
Naturally, any deviation there has to be accounted for in the offset.

[AAIIIC]

True enough, and I thought of that myself after I had posted but too late to go edit. I measured a few wheels before, all of which were 7" advertised width, and they varied from 7-7/8" to 8-1/8".

[lunarx]

Originally Posted by AAIIIC

True enough, and I thought of that myself after I had posted but too late to go edit. I measured a few wheels before, all of which were 7" advertised width, and they varied from 7-7/8" to 8-1/8".

Yes, so true.

Fortunately, offset is still usefull for tire position.
(Just not wheel position.)
Since the tire width is constant (virtually), regardless of the above mentioned wheel width variations.

Therefore, we all seem to agree that offset should be provided to a customer, so they get a chance to confirm fittment.

Any manufacturer who withholds it, is a tool and probably the inventor of 3 spoke wheels.

[atdeneve]

Well, looks like y'all reddy wrapped it up all nice n' tidy. Most greeable. Shnickety shnicks.