A set of wheels caught my eye while browsing on eBay and I was wondering if someone could interpret this info I got from the seller:

I'm not sure how they measure these, but I can tell you they are about 8.25 from bead line to bead line, 9.5 outside to outside on the rim. I assume they call it an 8 or 8.5..just a guess. Oh yes, they are 15's.

How is wheel width measured? On the inside from bead to bead or the total rim width outside to outside?

I've also asked a followup question on offset and will post that info when I get it. The seller had them on a '68.

Thanks!

The width is the total space between the inside of the outer flanges where the side of the bead contacts the rim. When the tire is mounted, this is the width of the outer edges of the tire bead itself, inside the metal.

Ken Styer

Offset is the measurement from the exact center of the rim width, to where the face of the rim bolts on to the hub. Set the rim down flat on it's inner edge. Measure to the surface where the rim touches the hub. Now measure the total width of the rim. If it is exactly center, you have 0 offset. If it is closer to the inside it is negative offset, closet to the outer edge is positive offset. The offset number is how far from center the measurement acutally is.

If the rim is 8"wide, the center point is 4". If the hub contact surface is only 3" from the floor, the rim has 1" negative offset.

Ken Styer

allot of rims have a millimeter offset measurment.

8x16 -10 is an 8 inch wide 16 inch high neg 10 mm offset
9x17 18 is an 9 inch wide 17 inch high pos 18 mm offset

mark v

Thanks Gents...!!!

So if I'm understanding things to this point these wheels would be considered 8" wide with a center of 4.25". Is offset an issue I need to worry about? According to the seller they were mounted on his '68 by a previous owner and neither experienced any clearance issues. The wheels are available because the seller wanted to go back to the original rally wheels for a more 'from the factory' look.

Thanks again!
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Jim O.
Save the Wave...!!!

If the wheels are too much negative, the tires can rub on the inside. If the wheels are too much positive the tires stick out too far, they look funny. In either case it centers the load in the wrong position relative to the wheel bearings. At worse this wear out the wheel bearing rapidly. It may not damage the bearing if it's not too far off, but then can severly affect the handling. If it's only slightly off, no problem. A half an inch (13mm) makes a difference.

Ken Styer

An 8 inch wide would have a 4 inch center. The 4.25 would be the measurement from ground to center if you are measureing it yourself, but then to the top of the rim laying on the floor would be about 8 1/2. This is due to the width of the bead supports on the rims.

Ken Styer

Seller informed me that the measurement from wheel rim to hub face is 4". With a total rim width of 9.5", center would be 4.75" (I made a math mistake above) making the offset on these wheels .75". A bit outside the recommended safe zone right?

btw - here's a pic from the eBay auction:

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Jim O.
Save the Wave...!!!

|UPDATED|1/24/2004 1:19:40 PM (AZT)|/UPDATED|

Hey Jim !
nice very nice looking wheels.
Normand

Well, I haven't bid on them yet but I do think they would look pretty sharp on "The Toy".
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Jim O.
Save the Wave...!!!