Goodyear Blue Streak racing tires

[my427cobra]

Can anyone tell me what the "typical" size would have been for a Goodyear Blue Streak racing tire used on the front (7.5" rim) of the 1965/1966 competition 427 Cobras.

Thanks

Cheers
Greg

[1985 CCX]

I think you are after G6, however I think original size was.....
5.50/9.75-15

AKA narrow in today's world

[my427cobra]

So what do the size designations mean?

R6 (vintage 1960's) vs G6 (more modern) tread type?

5.50 (section height)?

9.75 (tread width)?

Couldn't find info on Roger Krause website.

Cheers
Greg

[1985 CCX]

Gregg

Probably best to just go with standard modern G6 Blue Streak, no?
Roger Kraus Racing - Pricing


Tire Size DOT DIA T.W. Section
Width WHEELS
A 550-15 G-12 GOODYEAR N 25.5 6.6 9.3 on 7.0 6.5 - 9.5

[my427cobra]

Thanks Jeff. I should have been more detailed in my scenario.

I have an old 1965/1966 Halibrand Cobra II magnesium racing wheel (front :7.5" wide) that I'm cleaning up for display only purposes.

I have an opportunity to get an old 1965 Goodyear Blue Streak tire to mount on the Halibrand for display only purposes.

I was curious what the “correct” size Goodyear tire was used back in the day (1965/1966) on the front wheels so I don't get a tire that is too wide for the rim.

Cheers
Greg

[my427cobra]

Thanks Jeff. I should have been more detailed in my scenario.

I have an old 1965/1966 Halibrand Cobra II magnesium racing wheel (front :7.5" wide) that I'm cleaning up for display only purposes.

I have an opportunity to get an old 1965 Goodyear Blue Streak tire to mount on the Halibrand for display only purposes.

I was curious what the “correct” size Goodyear tire was used back in the day (1965/1966) on the front wheels so I don't get a tire that is too wide for the rim.

Cheers
Greg

[LMH]

Greg, this may help with how a tire is sized:



The actual tread width should be close to the wheel width. The section width should be a little wider than the wheel width. I've seen original Cobra 427's using Sunburst wheels with tires far too wide on the rear for the wheels. The tread edges actually curves down and the center of the tread sticks up. The owners are trying to fill up the rear fenders with big tires but the wheels weren't designed for the tires that wide. They just need to understand that there was a lot of excess space on wide fendered cars and leave it as originally intended. It's a pet-peeve of mine!

Note the rear tires that are far too wide for the wheels:



Larry

[*13*]

Wow, thats a lotta extra tread!

[my427cobra]

Thanks Larry. So I'm going to try to guess again.

For a Goodyear Blue Streak tire 5.50/9.75-15 from the mid 1960's:

5.50 is the tread width
9.75 is the section width
Should fit the 1965 magnesium Halibrand Cobra II (7.5" front) wheel.

Am I right?

Cheers
Greg

[cycleguy55]

Originally Posted by my427cobra

So what do the size designations mean?

R6 (vintage 1960's) vs G6 (more modern) tread type?

5.50 (section height)?

9.75 (tread width)?

Couldn't find info on Roger Krause website.

Cheers
Greg

Info:

http://rogerkrausracing.com/racetire...ra+2015cat.pdf

http://rogerkrausracing.com/racetire...+Race+2015.pdf

It looks to me that the 5.50 dimension is not directly related to section height, though it's a better match there than any other dimension.

9.75 probably represents the section width, not the tread width.

A current 6.00-15 G7 Blue Streak is listed as follows:
6.00-15: Diameter: 25.5" SW/Rim: 10.6"/8.0" Rim: 6.5"-10.0" Tread Width: 8.4"

[LMH]

The problem is the size they're rated for isn't the actual size in real life. It was a screwy way of sizing them back in the day. Do you have the tire that you can actually measure the tread width?
Larry

[cycleguy55]

Originally Posted by LMH

The problem is the size they're rated for isn't the actual size in real life. It was a screwy way of sizing them back in the day. Do you have the tire that you can actually measure the tread width?
Larry

Agreed, it's a real mess, and I bet the same numerical sizing was inconsistent from manufacturer to manufacturer, perhaps even from tire model to model within the same manufacturer. Kind of like sizing women's clothing. Yikes.

Do these tires make my rear end look fat?

[my427cobra]

The tire I will be getting is a 5.50/9.75X15. Since I'm going to need a tube anyways, I'm going to contact Roger Krause racing directly for more info.

Cheers
Greg

[cycleguy55]

Original tire sizes are supposedly included in these listings - though you have to dig a little to find them for each year, etc. Shelby Cobra data catalogue

I express no opinion as to the accuracy of the data!

[my427cobra]

Thanks Brian. Seen that website before. Good info but the tire detail is pretty thin and not very accurate.
Ideally for my research, this is the kind of detail I look for on each car model:

Tires: Goodyear, Power Cushion, HP, Nylon, Blue Dot, 8.15x15, 3-T, TUFSYN
or
Tires: Goodyear, Blue Streak, Sports Car Special, 5.95/9.75x15, Nylon, R4

Cheers
Greg

[cycleguy55]

Originally Posted by my427cobra

Thanks Brian. Seen that website before. Good info but the tire detail is pretty thin and not very accurate.
Ideally for my research, this is the kind of detail I look for on each car model:

Tires: Goodyear, Power Cushion, HP, Nylon, Blue Dot, 8.15x15, 3-T, TUFSYN
or
Tires: Goodyear, Blue Streak, Sports Car Special, 5.95/9.75x15, Nylon, R4

Cheers
Greg

I get a kick out of the "Alternative tire sizes" section, where any tire with a section width greater than 225mm is shown in red as "Warning: wide tire!" and anything 265mm or wider is shown as "Warning: very wide tire!".

I realize fitting these widths in some of the original cars may be more difficult than fitting them in the replicas, but it sure does speak to how tires and cars have changed in 50+ years, when small sporty cars carry meatier rubber than the original Cobras!

[CompClassics]

Don't forget that the Goodyear Blue Streak "Stock Car Specials" were used also.

[Dan Case]

Originally Posted by CompClassics

Don't forget that the Goodyear Blue Streak "Stock Car Specials" were used also.

And "BLUE STREAK SPEEDWAY SPECIAL" like when SAI ran on Cobras at Kent Washington.