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Understanding Wheel offsets & Link to all FAQ...

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Old 12-11-2003, 03:59 PM
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Question Understanding Wheel offsets & Link to all FAQ...

Understanding Wheel offsets & Link to all FAQ...

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The offset of a wheel is what locates the tire and wheel assembly in relation to the suspension. More specifically, it is the measured distance between the hub mounting surface and the center line of the rim. Below is an explanation of the various types of offsets which are pictured in the above graphic.

Positive Offset
A positive offset occurs when the hub mounting surface is on the street side (the side you see) of the center line of the rim. Most factory rims will have this type of offset.

Zero Offset
When the hub mounting surface is centered within the rim, it is known as a zero offset.

Negative Offset
If the hub mounting surface is on the brake side of the center line of the rim, it is considered a negative offset or "deep dish".

Note that extensive negative offset can potentially cause increased steering wheel kick-back and place additional stresses on the vehicle's entire suspension.

Special THANKS to Todd at Discount Tire for this info!

Last edited by Xsta Z 28; 12-11-2003 at 04:36 PM.
Old 12-12-2003, 04:00 PM
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You're welcome again!
Old 12-14-2003, 01:17 AM
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Cool, good post man!
Old 12-15-2003, 02:21 PM
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So how do adding spacers influence the offsets you can run?
Old 12-15-2003, 02:41 PM
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#1, I would never recommend a spacer. Too many variables for something to go wrong...and the last place you want something to go wrong is on the part that keeps your car shiney side up.

A spacer would make wheels that have too high of an offset (oe vette rears) fit without rubbing. They can also be used to push the wheels out farther for a more agressive look.

I believe H&R makes a stud/spacer combo kit that replaces the whole assembly. More expensive, yes. Safer...MUCH!
Old 12-15-2003, 02:56 PM
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A spacer, would effectively reduce the offset. For example:

If you have a 56 mm offset wheel and used a 5/16" spacer, ( ~ 8 mm) would make the wheel fit as if it were a 48 mm wheel.

Does that clarify? Like Todd states, spacers can be dangerous, especially if the wheel studs are compromised to be too short.

HR Springs makes VERY nice hub and wheel centric spacers ( meaning the the center is designed to fit around the "button" on the axle and they create a new "button" for the wheel to center onto.)
Old 01-14-2004, 06:09 PM
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so is the +50mm offset the right on for the 17x11 ZR-1,to fit a camaro?and not stick out
Old 01-14-2004, 06:12 PM
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whoops i now read the "does this fit" thanks
Old 01-15-2004, 08:31 AM
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Originally Posted by noah98SS
so is the +50mm offset the right on for the 17x11 ZR-1,to fit a camaro?and not stick out
YUP.
Old 01-18-2004, 03:44 PM
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Ok, maybe I am not the brightest guy here. I am considering a set of 16 x 8's torque thrust 2's. Found a great website. Problem is they have several offsets and bolt pattern dimensions to choose from. Does anybody here have an educated opinion of what dimensions I am looking for? 02 convert v6. (wifes car) Feel free e-mail me if you have the time. rmillercwi@msn.com thanks
Old 01-19-2004, 08:30 AM
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Originally Posted by rmillercwi
Ok, maybe I am not the brightest guy here. I am considering a set of 16 x 8's torque thrust 2's. Found a great website. Problem is they have several offsets and bolt pattern dimensions to choose from. Does anybody here have an educated opinion of what dimensions I am looking for? 02 convert v6. (wifes car) Feel free e-mail me if you have the time. rmillercwi@msn.com thanks

Bolt Pattern, 4.75" Offset, around 40mm should work just fine, although you may seriously want to consider 17" diameter, 9" width, looks killer.
Old 02-22-2004, 01:49 PM
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quick question... what does (+56mm offset with 7.4" backspacing) mean? i was looking at some zr1's and the offset is good but the 7.4" crap threw me off. what does that backspacing crap mean?
Old 02-23-2004, 12:02 PM
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Originally Posted by Brutal_LS1
quick question... what does (+56mm offset with 7.4" backspacing) mean? i was looking at some zr1's and the offset is good but the 7.4" crap threw me off. what does that backspacing crap mean?
Offset as stated above is the distance from the center line of the wheel to the lug mounting surface.

Back Space, is the distance fromt the back side of the rim to the lug mounting surface.

Back Space and Offset are actually related to each other.

To measure back space one lays the rim face down on the floor, sets a long straight edge accross the back of the rim, and with a tape mease determine the distance.

Hope that helps.
Old 03-07-2004, 06:46 PM
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Originally Posted by Xsta Z 28
Offset as stated above is the distance from the center line of the wheel to the lug mounting surface.

Back Space, is the distance fromt the back side of the rim to the lug mounting surface.

Back Space and Offset are actually related to each other.

To measure back space one lays the rim face down on the floor, sets a long straight edge accross the back of the rim, and with a tape mease determine the distance.
So is it correct to say that:
backspacing = (rim width / 2) + offset

Maybe I misunderstood the explanation of backspacing but that formula seems to fit based on your explanation. Am I way off here?
Old 03-08-2004, 09:23 AM
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Backspacing is the distance from the rear edge of the rim to the mounting surface. Offset is the distance from the rear mounting surface to the center of the rim. An 8" rim with 4" backspacing has 0" offset. A 10 " rim with the same backspacing has a + 2" offset. An 8" rim with +4" offset has 0" backspacing.

Theres more info in the stickies at the top of the forum
Old 06-17-2004, 01:12 AM
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got a question here.. i already got a thread going but i'm trying to get a straight answer.. im looking at American Racing wheels called REBEL i want the 18X10 rims for all the way around the offset and back spacing is 41mm offset and 7.125 backspacing.. im not sure of the stock WS6 wheel offset so that kinda thros me off as for figuring it out myself.. also i wana be running 295/35/18 tires on these wheels.. would they fit up front also tho? or em i better off with a 275 tire up front? thanx alot!
Old 06-21-2004, 04:25 PM
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I have answered quite a few ?'s in regards to the Rebel wheel. The 18" x 10" with a 41 mm offset whould fit the rear of an F-body just fine, I have reservations on if they will fit up front or not. Tires a 295 will fit in back but again I think a 295 is pushing the boundries . . .

BTW as far as I know and OEM 17" wheel from a SS or WS6 is 50mm offset and 7" back space.
Old 06-21-2004, 04:42 PM
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10 +41 works in the rear....285 tire. 295 you will need to roll. 10 +41 up front is realllllly pushin it with a 275 tire.
Old 06-22-2004, 08:27 AM
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Thumbs up

Originally Posted by Todd@DiscountTireDirect
10 +41 works in the rear....285 tire. 295 you will need to roll. 10 +41 up front is realllllly pushin it with a 275 tire.
Thanks for chiming in, I was wondering if it would fit . . . you would know best.
Old 08-03-2004, 09:59 PM
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My wheel and tire purchase from DTD was made sooo easy, by the guys there, and the wheel knowledge available to them at the spur of the moment.

All my offsets were perfect for my C5. The tires lined up perfect with the edge of the wheel well, and I have 1" clearance for the 305/35-18 Nitto DR's mounted on 18x10.5 Z06 Motorsports!

Thanks DTD!!!


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