U111 wheels

[kevin31 21]

Hello everyone!

 

I am looking to buy news wheels for my car and I found this model:

 

http://www.mhtwheels.com/rambler-u111-w-6133.htm

 

I would go for 18".

 

But....I am lost with baskpacing and offset measure.. according mhtwheels website:

 

18x8 with 4,5 backspacing and 1 offset (in inch I guess)

 

18x9,5 with 5,25 backsping and 1 offset.

 

What I don't understand, after some research I found a chart, and apparently, their is NO offset with those dimensions...

 

https://www.rsracing.com/TechWheel.aspx

 

Anybody can help me to undesrtand?

 

Merci

K.

 

[premix 12]

Hi, The chart is correct there is 0 offset with those measurements.

 

A 18x8 with 0 offset will have 4.5 backspacing and 4.5 poke. So a 8" rim is basically a 9" in total as rims are only measured to the tyre bead position.

 

Where as the backspacing is the total backspacing to the rear edge of the wheel. 

 

So the 9.5 rim is actually a 10.5 rim in total.

 

Hope this helps.

 

Andy

[MikeStang 247]

I have 17's in front and 18x9.5 in the rear.... They will fit with a 65/66 rear end under our car's or with stock rear end as long as the car isn't as low as mine is

[MikeStang 247]

Oh the 1 Offset they refer to is +1mm that's right 1 Millimeter LOL.

Basically Offset and Back Spacing USUALLY correlate in MOST cases but not always.

 

Its seems most of the newer style wheels they make now days are all listed with Offset and not back spacing, and all the old school wheels are in Back Spacing and not Offset.

 

Offset in Layman terms is nothing more than the relation of the mounting pad of the wheel to the center line of the wheel...

Basically if the rim is listed as a 9" Wide rim it is really 10" wide over all width from outer lip to outer lip.

So the center line of the wheel would be at 5".

and a wheel with a 1 or +1 Offset would have the flat mounting portion of said wheel at 1mm to the front of Center Line.

If I recall the more Positive Offset you have the Smaller the outside lip is and the more the tire moves inward.

The more Negative the Offset the more lip you gain and further out the tire is pushed.

 

Back Spacing is pretty much the same thing, except the measurement is taken from the Back outer most portion of the lip to the mounting pad of the wheel.

 

I calculated my fit like this.

 

Rim Mounting point is Fixed no matter what... Take a Plum Bob and tape it to the inner fender lip and let it drop down, then measure from the axle mounting flange out to the string of the bob. Take this measurement and subtract

1/2" for safety... This number is how far out you can go.

Next take a straight edge and lay it edge up on the rim mounting surface and have a friend hold it while you measure from the back edge of the straight edge in toward the closest place on the body or springs you can find... Write that measurement down and subtract 1/2" for safety.

Take your 2 measurements and add them together and that is your max rim width.

BUT just because you know the max width you now have to get the right offset OR Back space to make that MAx width rim fit in there... That's the fun part... You can make up some little gadgets with washers and rulers to figure it out easily enough tho.

I would like to add that the 17's up front and 18" out back look the best BTW

[MikeStang 247]

Here is an AWESOME Wheel calculator that actually tells you the amount of change that each wheel will make when installed.

Don't forget if you change wheel width but offset or Back space stays the same there will be a movement of the wheel location in or out because of the width change.

 

https://www.customwheeloffset.com/tire-wheel-backspacing-offset-calculators

[MikeStang 247]

I ordered my Wheels from Custom-Performance-Products On Ebay and paid a TOTAL of $742.50 for rims with lugs shipped to my door, and they were there in a week and in perfect condition.

My wheels are 17x8 5x4.5"Offset and 18x9.5" 5x4.5" offset if I recall correctly.... the 9.5 Should fit in the rear as long as the rear lips are rolled and its not lowered really and you have the correct 69 length Housing...I had the 72 mustang length housing and swapped to the 65-66 length because I wanted as much room as I could get... Hind sight the 69 length would have worked perfectly Im pretty sure.

[machm1970 180]

Here's another Mustang with similar wheels, nice look!

 

Matt

[MikeStang 247]

Keep in mind they have a smooth lip and stepped lip styles...2 Totally different looks... I run smooth lip in the back and what I consider a semi step lip in the front. meaning Its got a nice big smooth lip and the transition on the step is very minor

[kevin31 21]

Wow! Thanks for the reply and the explanation!!

 

 

Before to give back the wheels to my friend, my car was like that

 

 

Front 17x8 with 4,75 backspacing 245x45/17

Rear 17x9 with 5,5 backspacing 275x40/17

 

Perfect fit! (for me)

 

I would have liked to have the same rims but in 18" all corner. But I never got an answer from Coy's Wheel....

 

So U111 rims could be the good choice. For sure, the 18x9,5 will not fit at the rear...so I can forget it.

Go with 18x8 with 4,5 in all corner...or maybe do the same as you MikeStang, keep the 17" at the front.

 

The thing is I cannot order wheels to make a try...as the shipment is awfully expensive.. AHAH!

[MikeStang 247]

The 9.5 should fit the rear provided your car is not lowered like mine is.

As long as the wheel lip is above the tire it should work easily and if its not above the tire I would suggest rolling it..

The 18's in the front should fit as well, but I KNOW the 17s will.