Tires and Wheels

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Krfjkm
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Tires and Wheels

Post by Krfjkm »

Hi folks--

I would like to add some different tires and wheels for my 1965 Corsa Convertible. Will keep my stock set up as well but would like to have something a bit bigger.

It is confusing to try to buy but I know you guys can help--

Here is what I am considering:

American Racing Torque Thrust 15x7 5x4.75 (got some advice from forum member syntheticblinkerfluid) With 4" to 4.5" of backspace-- thinking about 205/50-15 tire size.

I really don't want any tire rub---- Anything I am missing?
Last edited by Krfjkm on Mon May 01, 2017 9:05 pm, edited 1 time in total.
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SyntheticBlnkerFluid
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Re: Tires and Wheels

Post by SyntheticBlnkerFluid »

You are a bit confused for sure. [emoji1]

5x4.75 is the lug pattern, which is correct for your car.

Wherever you are looking at wheels at, you have to find what the backspace is. For a 15x7 wheel, you need at least 4" of backspace, 4.5" is probably ideal. Depending on the manufacturer, this may be listed as offset, instead of backspace. If that's the case, this is read in Millimeters. The minimum you want is a Zero offset (4" backspace on a 7" wide wheel). +13 is ideal (4.5" backspace).

205/50-15 is a good size to use, but just realize your speedometer will be off by almost 5 mph.

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1968 Monza 140 4-Speed Posi

Rob
Chebanse, IL
Krfjkm
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Re: Tires and Wheels

Post by Krfjkm »

Thanks for setting me straight! Really appreciate the advice and the picture / diagram--- I updated my question with your advice-- you know your tires and wheels!
66vairguy
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Re: Tires and Wheels

Post by 66vairguy »

Normal backspace is 4.25" with a 5.5" wide 13" rim. A six inch wide rim with a 4.5" backspace will have the same geometry IF you run the same tire diameter as the 7.00x13. The 205/70x14" is right on the money and fits a 6" wide x 14" rim. The 14" tire is available by a few brands. I like the classic tall sidewall and a 70 series has a better ride.

The ideal tire diameter produces 825 revolutions per mile, but can go to 850 revolutions per mile and the speedometer only be 3% fast, or 2 MPH at 60. If you want to go with the 15" check the 205/60X15". It's about 842 revs per mile (Tire Rack in spec section) and the ideal rim width is 6", but it will fit on a 7" wide rim - so go with a 6" wide rim with a 4.5" backspace. If you want the 7" rim you'll still have to go with a 4.5" backspace as that's about the max to clear the suspension and inner wheel well in a turn.

If you go with less than 4.5" backspace it will lead to odd steering response like, bump steering, wandering, etc. The farther from ideal backspace and factory tire diameter, the worse the steering feel.
Krfjkm
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Re: Tires and Wheels

Post by Krfjkm »

I want the American Racing Torque Thrust wheels and I checked on the availability of 15x7 5x4.75 with 4.5" backspace and they said that the 15x7 were only available with 4" backspace.

So here is my question which one would fit my 65 Corsa better?:
-- 15x7 5x4.75 with 4" backspace
or
-- 15x8 5x4.75 with 4.5" of backspace

Please let me know what you think--
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bbodie52
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Re: Tires and Wheels

Post by bbodie52 »

Basic reference which you should review...

Sizing Corvair Wheels and Tires

:link: http://autoxer.skiblack.com/tires.html
  • For reference, more backspace moves the wheel further in the wheelwell, less backspace brings it out. Maximum backspace for an early with 15" wheels is 5", late is 5 1/4".

  • Lates can easily handle up to 7" wide wheels in the front, with up to 8" (!) wide in the rear with the correct backspacing.

  • When fitting new wheels the rim should ideally remain positioned in and out relative to the hub as close to stock as possible (yes, tires sticking way out from the fenders are a bad thing), which can be determined by measuring the backspacing. This dimension is probably the most important, because if the tire is not located correctly the wheel bearings will wear prematurely due to uneven loading, the tires may hit the inside or outside of the fender or other components, and the car will likely dart around when you hit a bump.

  • Late: Many people have used a variety of 14", 15" and 16" wheels on late model Corvairs, one of the most popular donors is the Camaro. Although these wheels do bolt up, you must be careful with the backspacing, especially on those 7" wide or wider. I suggest using the 6" wide versions, since they mount a 205 very nicely and are easier to find in a backspacing of 4", which fits the late Corvair well. You will need at least 4" of backspace on a 7" wide rim, and 4 1/2" is much better for steering feel and clearance.

  • Personally, I've been very happy using 205/60-14 tires on 14" x 6" Chevy steel wheels on the front, and 245/60-14 tires on 14" x 7" Chevy steel wheels rear. Backspace is pretty close, 4" (ideal would be 4 1/2") front, 4 1/4" (optimum 5") rear. With these, any road imperfections are noticeable, but the ride isn't especially harsh and the increase in grip is quite large. This front tire size gave me an accurate speedometer too, although it is technically a bit short.
Here are some 14" tire sizes I use on my 1966 Corsa convertible...

Front: BF Goodrich Radial T/A P205/70 R14
Overall Diameter: 25.4" Revs per Mile: 821 Sect. Width: 8.2" Tread Width: 6.4"
Rear: BF Goodrich Radial T/A P235/60 R14
Overall Diameter: 25.1" Revs per Mile: 829 Sect. Width 9.5" Tread Width 8.7"
1966 Blue Corsa Convertible - 7.jpg
1966 Blue Corsa Convertible - 13.jpg
1966 Blue Corsa Convertible - 14.jpg

Some alternatives to consider...

15"
American Racing Torque Thrust D. 15X7 rear with 225/50 BFG G-force Kd. Kd stand for Key application Dry (a summer tire).

The tires are directional and asymetric so there is a left and a right . The rating is AA , A, 200. They are Y-rated for speed.

The fronts are 15X6 with 205/50s
16"
American Racing Torque Thrust II's. 16x7, 4 inch backspace. 205-55 ZR16 BFGoodrich G-Force tires.
17"
Scott Howey wrote:Rear = 17x8, 4.5" backspace, 225/50/17 tires. Front= 17x7, 4" backspace, 215/45/17 tires.
The Tire Rack website is a good source for tire specifications and availability in various brands and performance settings.

Image :link: https://www.tirerack.com/content/tirera ... epage.html
Brad Bodie
Lake Chatuge, North Carolina
Image 1966 Corvair Corsa Convertible
Krfjkm
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Re: Tires and Wheels

Post by Krfjkm »

Thanks Brad!

So 15x6 5x4.75 with a 4" backspace and a 205 60 15 tire all around? Does that sound right?

Thanks also for the pictures of your car---- it is a nice one!
66vairguy
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Re: Tires and Wheels

Post by 66vairguy »

The 15"X6"wide with a 4" backspace will work, but not optimal.

O.K. Backspace ---- Stock Corvair was 4.25" back space with a 5.5" wide rim. Take the rim width GREATER than 5.5" and divide by 2 and add to 4.25". So a 6" rim is 0.5 inch wider than stock divided by 2 = 0.25" added to the 4.25" backspace and - tada - you get 4.5" backspace.

A 7" rim would need a 5" backspace - BUT 4.5 is the practical maxium on a Corvair. With your 4" backspace on a 7" rim you are 1" off center and just my opinion, but that's bordering on poor steering response.

A 8" rim would need a 5.5 " backspace, so your 8" wide with a 4.5" backspace is off center 1" inch and you are pushing clearance limits and a 205 tire on a 8" wide rim is a tight fit and a guaranteed curb scraping of the rim edge in your future.
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bbodie52
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Re: Tires and Wheels

Post by bbodie52 »

P205/60R15 (all, good replacement for 1966 - 69 7.00-13)
There are currently 35 tires listed on the Tire Rack in that size, which gives you a lot of choices in various brands and performance characteristics. Acceptable rim width range in this tire size is generally 5.5-7.5", according to the specs listed on the Tire Rack. Using the same size on all four corners of the car allows you to rotate them periodically to maximize longevity and promote even tire wear. There are many reasonably priced all-season performance tires in this size. B.F. Goodrich even offers a Radial T/A in this size, if you would like to run Raised White Letter tires.

You can read many consumer reviews of these tires to narrow it down to the brand and tire model you would prefer, using the link below...

Image
:link: https://www.tirerack.com/tires/TireSear ... iameter=17

RADIAL T/A Size: P205/60R15
Image
Image

On my 1965 Corsa convertible, I was running classic Ansen Sprint wheels with Goodyear Raised White Letter tires.
This is how it looked (14x7" rims)...

Image
Image
ANSEN SPRINT
Size:15x7
Offset:0mm
Backspacing:3.94"
Bolt Pattern:5-475
Rec. Tire Size:225/60-15
Weight:16.0 lbs.
Finish:Polished

Image
Image
VNT71R
Size:15x7
Offset:0mm
Backspacing:3.94"
Bolt Pattern:5-475
Rec. Tire Size:225/60-15
Weight:17.6 lbs.
Finish:Polished
Construction:1pc. Gravity Cast

Image
Image
VNT70R
Size:15x7
Offset:0mm
Backspacing:3.90"
Bolt Pattern:5-475
Rec. Tire Size:225/60-15
Weight:16.8 lbs.
Finish:Silver w/Polished Lip
Construction:1pc. Gravity Cast

The American Racing wheels in 15x7 rims are all a little less than 4" backspacing. Those listed above (on the Tire Rack) were close.

If you were to buy the wheels and tires in a combo on the Tire Rack, I believe you can save some money because they will mount and balance them for you before shipment, and they don't charge extra for the mounting and balancing or valve stems.
Tire Rack wrote:Hunter Road Force™ Mounting and Balancing included free of charge with your Tire & Wheel Package.

Hunter Road Force Mounting and Balancing

In order to assure customer satisfaction, Tire & Wheel Packages purchased at the Tire Rack are tested before shipment at no additional charge to our consumers using the Hunter Engineering GSP9700 Vibration Control System to evaluate and eliminate nearly all possible wheel- and tire-related vibration causes.
:link: https://www.tirerack.com/tires/tiretech ... ?techid=40
Brad Bodie
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Image 1966 Corvair Corsa Convertible
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jetcat
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Re: Tires and Wheels

Post by jetcat »

I bought the American Torq 15x7 and Toyo 205x15x60 tires. They fit OK and fill the wheel well nicely. Speedo is not greatly affected. The closest to rubbing is the fronts. Just misses the front fender lip at full steering lock. If you ever convert to front disc brakes, it will rub because it adds almost 1/2" to the front track width.
Image

After installing front disc brakes.

Image

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Krfjkm
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Re: Tires and Wheels

Post by Krfjkm »

Thanks Jetcat--- what did you do once you added disc brakes-- that last picture looked pretty tight!
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jetcat
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Re: RE: Re: Tires and Wheels

Post by jetcat »

Krfjkm wrote:Thanks Jetcat--- what did you do once you added disc brakes-- that last picture looked pretty tight!
Too tight....
Since I'm repainting the car, I reworked the body to get another 1/4" on the front fender lip. The aluminum trim is soft so it easily conforms to the mods. The other option is milling off a 1/4" on the wheel mounting surface or using 195x60x15 on the front. The 205's really look nice and my area, we have rough roads, so I prefer higher profile tires. However, 50 series would also fix it.
The biggest problem with the current fit, it doesn't leave you any options for different caster adjustments.

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Kyle_in_Mich
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Re: Tires and Wheels

Post by Kyle_in_Mich »

66vairguy wrote: Tue May 02, 2017 7:48 pm The 15"X6"wide with a 4" backspace will work, but not optimal.

O.K. Backspace ---- Stock Corvair was 4.25" back space with a 5.5" wide rim. Take the rim width GREATER than 5.5" and divide by 2 and add to 4.25". So a 6" rim is 0.5 inch wider than stock divided by 2 = 0.25" added to the 4.25" backspace and - tada - you get 4.5" backspace.

A 7" rim would need a 5" backspace - BUT 4.5 is the practical maxium on a Corvair. With your 4" backspace on a 7" rim you are 1" off center and just my opinion, but that's bordering on poor steering response.

A 8" rim would need a 5.5 " backspace, so your 8" wide with a 4.5" backspace is off center 1" inch and you are pushing clearance limits and a 205 tire on a 8" wide rim is a tight fit and a guaranteed curb scraping of the rim edge in your future.
Are all of these assuming you are trying to fit the front of the car correct?

Putting an 8" wide rim on the rear of the car with 4.5 in backspacing would not be detrimental to the handling since it is not turning correct?
Krfjkm
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Re: Tires and Wheels

Post by Krfjkm »

I forgot to post a picture with my wheels --- 15x7 with 205/60's ---- 4.25 " backspace--- I absolutely love the way it rides---

Thanks for all the help!

IMG_1246.JPG
64powerglide
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Re: Tires and Wheels

Post by 64powerglide »

Roll over!!!!!! :tu: :tu: Good looking wheels!!
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