question for the wheel gurus

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Pete - 06 Apr 2006 01:46 GMT

Ok, this is a bit of an oddball question. I'm trying to find the 99 civic
coupe oem rim offset; that is, the distance from the centerline of the rim
to the mounting flange. I need to know this because I want to upgrade to 14
x 6" wide alloy wheels. Those have a 38mm offset. The stock rim is 14 x 5".
There isn't alot of clearance between the inside of the rim and the strut
arm. If the offset is als 38mm on the oem, then I can't do it. Someone at
a performance shop told me that it's usually 50mm and it should be indicated
on the rim but I didn't see it. If it is 50mm, then the 14 x 6" wheels are
no problem at all.

Thanks,
Pete

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Alan - 06 Apr 2006 03:57 GMT

> Ok, this is a bit of an oddball question. I'm trying to find the 99 civic
> coupe oem rim offset; that is, the distance from the centerline of the rim
[quoted text clipped - 5 lines]
> on the rim but I didn't see it. If it is 50mm, then the 14 x 6" wheels are
> no problem at all.

The numbers you're saying mean "positive" offset. If the wheel is
laying down on its side with the face up, positive means that the
flange is higher from the center line of the wheel, which means that
the inside edge of the wheel is going to be farther in when mounted on
the car.
So it appears that the 38mm offset on a 14 x 6 wheel would have the
same clearance as the 50mm offset on the 14 x 5 steel rim. (1/2 inch
being about 12mm... the other 1/2 inch would stick out from the car).
Steel rims don't usually have the offset number stamped on it. What you
can do to measure the offset of a wheel is lay it down on a flat
surface (with no tire on it) and measure the bottom outer edge to the
top outer edge and divide by 2 to get your center line. For example
let's say the steel rim is 150mm from top edge to bottom. Half would be
75mm. Then measure from the ground to the bottom edge of the center
hole or lug hole, lets say it's 125mm. Subtract 75 from 125 and you
have your wheel offset.
NOTE: Rear wheel drive cars have a smaller offset for some reason.

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jim beam - 06 Apr 2006 05:31 GMT

>>Ok, this is a bit of an oddball question. I'm trying to find the 99 civic
>>coupe oem rim offset; that is, the distance from the centerline of the rim
[quoted text clipped - 23 lines]
> have your wheel offset.
> NOTE: Rear wheel drive cars have a smaller offset for some reason.

nothing to do with the end driven. it's determined by the steering
scrub radius. modern cars have negative scrub radius because of the
self stabilizing benefits in the event of front tire blow-out. the only
way to achieve negative scrub is by having a large negative offset. old
vehicles and still a lot of trucks have/had positive scrub and those
wheels have a much smaller offset.

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Pete - 07 Apr 2006 06:00 GMT

Thanks for the info. I found the offset on the oem wheel to be 45mm. Would
a change to a 38mm offset wheel be acceptable for the civic? Or is any
change from oem a bad idea?

>> Ok, this is a bit of an oddball question. I'm trying to find the 99
>> civic
[quoted text clipped - 30 lines]
> have your wheel offset.
> NOTE: Rear wheel drive cars have a smaller offset for some reason.

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