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-   -   rubbing on a 18-inch wheels (https://www.corvetteforum.com/forums/c3-tech-performance/4138107-rubbing-on-a-18-inch-wheels.html)

ariba 05-12-2018 04:21 PM

rubbing on a 18-inch wheels
 
Hello
i just installed my 18” Wheels front 18x8 rear 18x9.5 255 45 18. I have a 2” adapters all around I am not having a problem with the rear. The rubbing is only on the front it rubbes to the frame and a little on the sway bar. The offset is 40 and the back spacing is 6.020 I will send some photos.
The drivers side tire is little rubbing on the fender maybe aliment issues? But not sure.

1. Do you think 2.5 adapters will fix the problem?

Othere thing in the future I am am considering aftermarket a bolt on 18 inch wheels without any mods. If you have any please let me know.
But First I will give another adapters a shot.

https://cimg3.ibsrv.net/gimg/www.cor...c072d986a.jpeg
https://cimg4.ibsrv.net/gimg/www.cor...88a3c937b.jpeg
https://cimg6.ibsrv.net/gimg/www.cor...20002af13.jpeg
https://cimg7.ibsrv.net/gimg/www.cor...91cf73a41.jpeg
https://cimg2.ibsrv.net/gimg/www.cor...fa34d8439a.png

mrvette 05-12-2018 04:32 PM

I recommend Tony's Corvette shop.....Gaithersburg Md.....

I suspect you have too tall a tire there, but it looks like the fender maybe too tight for a stock fitting....and yes, I too had to limit my steering by putting about 1/2" pad buildup on the lower control arms where the steering rubs......see below but I have 89 vette rims....17x9.5 and 255/50/17 tires and stock wheel center line ...so no suspension loading.....in rear I had to move the ebrake cable tab off the trailing arm to behind the rotor, some guys put it on top.....allows for wider tires.....

:smash::thumbs:

ariba 05-12-2018 05:16 PM

[QUOTE=mrvette;1597186107]I recommend Tony's Corvette shop.....Gaithersburg Md.....

Thanks
I did call them 10 days ago they told me there is a waiting lest for more than 45 days :ack:

I was looking for them to check my new carb issue.

DUB 05-12-2018 05:30 PM

I run into this some times when people want wheels like you have chosen. And due to you are changing the engineered dynamics of the effective turning radius on a car that is not set up for this type of wheel.

You have to remember...if the wheel you are choosing is so much wider that its centerline is correct to the facotry set -up...but now due to it being wider. And lets say 2" wider. So you went from a 8" wide wheel to a 10" wide wheel. Half of 2" is 1". The 1" is now on the inside where you can run into conflict....but that added 1" on the outside is not causing the wheel to protrude past the wheel well lip.

THEN if the tire that is being put on this wheel. If the tires circumference is larger than the orgianl facotry wheel...that has to be taken into account.

AND if you are concerned that the wheel stays tucked under the fender and is NOT sticking out past the edge of the wheel well area. Adding a wider spacer/adapter is up to you.

IF you DO NOT want the wheel sticking out and looking odd. Then you have to sacrifice some of your turning radius and modify the lower a-arm stop point so that when the wheel is turned...it stops before your tire scrubs.

DUB

ariba 05-12-2018 06:06 PM


Originally Posted by DUB (Post 1597186407)
I run into this some times when people want wheels like you have chosen. And due to you are changing the engineered dynamics of the effective turning radius on a car that is not set up for this type of wheel.

You have to remember...if the wheel you are choosing is so much wider that its centerline is correct to the facotry set -up...but now due to it being wider. And lets say 2" wider. So you went from a 8" wide wheel to a 10" wide wheel. Half of 2" is 1". The 1" is now on the inside where you can run into conflict....but that added 1" on the outside is not causing the wheel to protrude past the wheel well lip.

THEN if the tire that is being put on this wheel. If the tires circumference is larger than the orgianl facotry wheel...that has to be taken into account.

AND if you are concerned that the wheel stays tucked under the fender and is NOT sticking out past the edge of the wheel well area. Adding a wider spacer/adapter is up to you.

IF you DO NOT want the wheel sticking out and looking odd. Then you have to sacrifice some of your turning radius and modify the lower a-arm stop point so that when the wheel is turned...it stops before your tire scrubs.

DUB

Thank You for helping and the front wheel is 18x8. I don't think it's that wide!..

Fredtoo 05-12-2018 06:29 PM

While it looks like the OD is close to oem spec, the tread width is too wide.
As noted above, reducing the steering lock would stop them from hitting.

I would be interested to see if a 245/45/18 would buy you enough clearance to make it work


https://www.tirerack.com/tires/tires...omCompare1=yes

SIZE UTQG MAX.
LOAD Max. Inflation Pressure Tread Depth Tire Weight Rim Width Range Meas. Rim Width Sect. Width Tread Width Overall Diam. Revs. Per Mile Country of
Origin*
255/45ZR18
103Y XL
340 AA A 1,929 lbs. 51 psi 10/32" 26 lbs. 8-9.5" 8.5" 10" 8.8" 27" 769 DE

ariba 05-12-2018 08:27 PM


Originally Posted by Fredtoo (Post 1597186688)
While it looks like the OD is close to oem spec, the tread width is too wide.
As noted above, reducing the steering lock would stop them from hitting.

I would be interested to see if a 245/45/18 would buy you enough clearance to make it work


https://www.tirerack.com/tires/tires...omCompare1=yes

SIZE UTQG MAX.
LOAD Max. Inflation Pressure Tread Depth Tire Weight Rim Width Range Meas. Rim Width Sect. Width Tread Width Overall Diam. Revs. Per Mile Country of
Origin*
255/45ZR18
103Y XL
340 AA A 1,929 lbs. 51 psi 10/32" 26 lbs. 8-9.5" 8.5" 10" 8.8" 27" 769 DE

Thanks
The tire wheel shop recommended 235 45 18 but I didn't liked the idea, and I am seeing a lot of c3 are using 245 45 18 in the front I am considering 245 but I don't want to buy a 245 and in the end it will rub :smash:

carriljc 05-12-2018 10:32 PM

Going to 245s seems like a lot less hassle than modifying everything else? Perhaps you can get whatever shop you got your tires mounted at to test fit some for you. After all, you spent good money getting there I gather.

You can visualize tire size changes using this:
https://tiresize.com/wheel-offset-calculator/

even has a place to enter your offset.

cagotzmann 05-13-2018 01:03 AM


Originally Posted by ariba (Post 1597186045)
the back spacing is 6.020
The drivers side tire is little rubbing on the fender maybe aliment issues? But not sure.

1. Do you think 2.5 adapters will fix the problem?

Othere thing in the future I am am considering aftermarket a bolt on 18 inch wheels without any mods. If you have any please let me know.
But First I will give another adapters a shot.

Here is what you need to work towards.

Front
18x8" wheel -12mm offset / 4" backspace. 27" Dia tire.

Rear

18 x 9.5" -12mm offset 4.75" backspace 27" dia tire.

You will most likely find tires that are 26.65" dia

front 245 45R 18
rear 275 40R 18

This is for a car without any mods required in most cases.


Below are 18 x 9.5 (4.75" BS) all around with 275 40R 18 Tires.

https://cimg7.ibsrv.net/gimg/www.cor...5ebb111d69.jpg

Rear sway bar clearance.


https://cimg9.ibsrv.net/gimg/www.cor...69e88166d1.jpg

sug 05-13-2018 03:30 AM


Originally Posted by cagotzmann (Post 1597188570)
Here is what you need to work towards.

Front
18x8" wheel -12mm offset / 4" backspace. 27" Dia tire.

Rear

18 x 9.5" -12mm offset 4.75" backspace 27" dia tire.

You will most likely find tires that are 26.65" dia

front 245 45R 18
rear 275 40R 18

This is for a car without any mods required in most cases.


Below are 18 x 9.5 (4.75" BS) all around with 275 40R 18 Tires.

https://cimg7.ibsrv.net/gimg/www.cor...5ebb111d69.jpg

Rear sway bar clearance.


https://cimg9.ibsrv.net/gimg/www.cor...69e88166d1.jpg

Nice wheels.:thumbs:

gkull 05-13-2018 09:32 AM

Your tires are just too tall of diameter. You just need 255/40/18. Which are 26 inches dia.

DUB 05-13-2018 09:50 AM

So now that we all know that the wheel is at basic correct width as the factory wheel...and if it is centered like the factory wheel with the
spacer hub...then it seems to be all boiling down to the tire itself...or...modifying the stop on the lower a-arm to keep it from hitting.

On another note...You might want to address this.

In the photo below...it really looks like your rubber brake hose is kinking or darn near kinking which is NOT good.


https://cimg3.ibsrv.net/gimg/www.cor...5187d66967.jpg

DUB

wer2xu 05-13-2018 08:57 PM


Originally Posted by DUB (Post 1597189442)
So now that we all know that the wheel is at basic correct width as the factory wheel...and if it is centered like the factory wheel with the
spacer hub...then it seems to be all boiling down to the tire itself...or...modifying the stop on the lower a-arm to keep it from hitting.

On another note...You might want to address this.

In the photo below...it really looks like your rubber brake hose is kinking or darn near kinking which is NOT good.
DUB


:eek: Good catch, I did not even notice that because the brake line was so well camouflaged.
You need to get that sorted as that is close to being a very bad day.

MelWff 05-14-2018 04:25 PM

you are using 2" spacers, are you using longer wheel studs?

gkull 05-15-2018 12:25 PM


Originally Posted by MelWff (Post 1597198167)
you are using 2" spacers, are you using longer wheel studs?

No, Nuts hold the adapter to the original axle wheel studs and the adapter has studs.

I would recommend buying correct wheel back spacing when ever possible. I have 2 inch adapters because of 13 inch wide rear wheel with 6.5 BS

NewbVetteGuy 05-15-2018 02:03 PM


Originally Posted by gkull (Post 1597189341)
Your tires are just too tall of diameter. You just need 255/40/18. Which are 26 inches dia.

I have a 1979 with 255/45/18" tires and they don't rub at all, for what that's worth... Stock FE7 Gymkhana sway bar up front.


Adam

NewbVetteGuy 05-15-2018 02:04 PM


Originally Posted by ariba (Post 1597186045)

Niche Misano wheels in black?!? You have to post a photo of these things on your car; I think I'd really like that look...


Adam

gkull 05-15-2018 04:52 PM


Originally Posted by NewbVetteGuy (Post 1597204372)
I have a 1979 with 255/45/18" tires and they don't rub at all, for what that's worth... Stock FE7 Gymkhana sway bar up front.


Adam


On the Tire Rack website they list your 45 series at 27 inches tall and the 40 series at 26 inches tall. The wheel design determines how close the tire is at lock to lock and the frame. My street tire is 275 front and 295 slicks at the track. on 10 inch wheels


The 26 inch lowers the front end and would get rid of the posters scraping.

Fredtoo 05-15-2018 05:10 PM

How accurate are these diameter dimensions for tires?
Do they really measure the same on the car as on the spec sheet?

gkull 05-15-2018 06:50 PM

Someone told me that tire manufacturers have to comply with DOT standards. Tire listed diameter is at 90 % of max pressure unmounted and then mounted with a weight of 60 % of the max weight rated when the tire is new

so if you put about 45 psi in a maximum amount of 51 psi which is the norm for modern ultra high performance tires. You will be very near the listed diameter

tire rack also lists revolutions per mile so with a little math you can figure out the exact diameter


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