91 replies to this topic

[Jim Drago]

What does everyone think of gentleman's agreement to run 7.5 tires for the Sprints race?

[Tom Sager]

What does everyone think of gentleman's agreement to run 7.5 tires for the Sprints race?

You mean just like the POG agreement from 10 years ago?  I recall several frontrunners that chose the dark side then.  

[Jim Drago]

You mean just like the POG agreement from 10 years ago?  I recall several frontrunners that chose the dark side then.  

Well if I can get all of you to agree, then i run the faster

[trimless]

What does everyone think of gentleman's agreement to run 7.5 tires for the Sprints race?

Is there any real evidence that the 7's are faster?  I ran the 7.5's for the first time a couple of weeks ago, 4 total sessions for a weekend.  Could not say that I felt the 7.5 was any slower or faster. 

[Jim Drago]

Is there any real evidence that the 7's are faster?  I ran the 7.5's for the first time a couple of weeks ago, 4 total sessions for a weekend.  Could not say that I felt the 7.5 was any slower or faster. 

Not that I am aware.. Just thinking narrower and lighter at Road America should be faster?  Data from the few who tried elsewhere suggests the 7.5 is faster.  I have not back to backed them, trying to avoid a costly and senseless test

Jim

[FTodaro]

Is there any real evidence that the 7's are faster?  I ran the 7.5's for the first time a couple of weeks ago, 4 total sessions for a weekend.  Could not say that I felt the 7.5 was any slower or faster. 

I was told that its the same compound and construction except the rib design. Is that not the case? I have not weighed them.

[Caveman-kwebb99]

Why would there be any gentleman's agreement that harms the guys that want to run their 27 year old sm7 tires and circulate thought their 6 sets of them. Just like we heard in the tire marking argument.

Jim you need to buy 8 sets of stickers thanks to the smac!

This is one reason I will be buying a replacement race rather then spending money on tires to race.

Smac dropped the ball so why do you think some other front runners who opposed tire marking would want to agree with you now????

[Tom Sager]

7.5 tread area is slightly wider but the tire overall (aero-wise) is not wider.  If you put each tire flat on a floor next to each other they are essentially level at the tallest part of the sidewall. 

[-P-]

7.5 tread area is slightly wider but the tire overall (aero-wise) is not wider.  If you put each tire flat on a floor next to each other they are essentially level at the tallest part of the sidewall. 

Not sure that is clear. Are you saying contact patch is wider but overall width from the widest horizontal measurement point is the same?

 

*edited: for clarity

[DrDomm]

This is way too complicated.

[MPR22]

The winner of the SCCa runoffs will be on 7.5. I would bet a lot of money that the winner of Sprints will be on the 7.5.

[Tom Sager]

Not sure that is clear. Are you saying contact patch is wider but overall width from the widest horizontal measurement point is the same?

 

*edited: for clarity

Yes.

[Tom Sager]

I was told that its the same com of both tires appears to be the same. 

 

Durometer reading of both tires looks to be the same. 

[DrDomm]

Annual tech: 2019 annual tech validity has been extended.  Any annual conducted on or after March 12^th will be valid. 

 

This is not mentioned in the updated Supps...but I found this in Fastrack...

 

"For 2020 only, current annual technical inspections will be extended 3 months past their original expiration date (valid for a total of 15 months). All expiration extensions will end on 12/31/2020. For example, an original expiration date of June 15, 2020 will have an extended expiration of September 15, 2020. All inspections with an original expiration date between September – December 2020, will have an extended expiration date of 12/31/2020."

 

FYI.

[Marc Cefalo]

This is way too complicated.

 

comparison back to back:

 

https://www.facebook...03166699823972/

[Steve Scheifler]

comparison back to back:

https://www.facebook...03166699823972/

Thanks. I’m not sure the more squared off shoulder is an “improvement“ that we want. In some tires from the past that design contributed to a falloff in performance and even a perceived change in optimal setup between a new and used tire. It depends on multiple factors, with both tire and car, but I don’t think it’s a given that it’s better.

[Ron Alan]

Spent the weekend(June 5,6,7) at Laguna Seca as SCCA was allowed to run their event. Despite the mask police(you got 2 warnings and then were kicked out)and every competitor was only allowed 1 guest or crew...it was good to get back out!!

 

I'm hoping this isnt the norm but I saw several sets of SM7.5 with tread separation??? One set had a couple tires with "chunks" missing...2" in diameter and almost to the cord. These tires had 5 cycles. The other set I saw on the discard pile at the tire mounter...2 tire were very "de-laminated". 10" sections of the tire it looked like you could slid a screw driver under/between the layers?? Not good! I wish i had taken a picture now.

[Jim Drago]

Spent the weekend(June 5,6,7) at Laguna Seca as SCCA was allowed to run their event. Despite the mask police(you got 2 warnings and then were kicked out)and every competitor was only allowed 1 guest or crew...it was good to get back out!!

 

I'm hoping this isnt the norm but I saw several sets of SM7.5 with tread separation??? One set had a couple tires with "chunks" missing...2" in diameter and almost to the cord. These tires had 5 cycles. The other set I saw on the discard pile at the tire mounter...2 tire were very "de-laminated". 10" sections of the tire it looked like you could slid a screw driver under/between the layers?? Not good! I wish i had taken a picture now.

great

I think Rich powers had that issue the first weekend out and told him it was a mold issue or something?  Loading up some more sm7's

[Ron Alan]

I cant speak to the set I saw on the dump pile...but the set that had chunks missing were probably purchased early on in production.

[MPR22]

great

I think Rich powers had that issue the first weekend out and told him it was a mold issue or something?  Loading up some more sm7's

Start the PO7.5 agreement process then, go to the SM7 card.  Hopefully Hoosier will have enough spares to cover those of us that will be on 7.5.