Chevrolet SS wheel spare tire question

[jeffschevelle]

I'm late to the party. First, I see nothing that suggests that that tire is not an original 1969 tire. Tread is consistent with the 1969 Firestone tread layout, which is what Coker and others have used as the repro. 67 model year to mid 68 Wide Oval is the version that is not reproduced.

Second, not all DOT marked tires have a standardized DOT date code. The initial DOT marking requirements were only to have "DOT" and a manufacturer's code. The standardized DOT date coding requirement came along later.

Third, there is no way (not that anyone has shared at least) to decode the numeric codes on Firestones before standardized DOT date coding became required.

***
Regarding the start date of DOT markings, I spent many hours about a year ago finding and then reading the entire "National Traffic and Motor Vehicle Safety Act of 1966", and every single one of the DOT tire markings regulations that were issued from 1967 through the early 70's. I even did a spreadsheet with the timeline of what markings were required and when!

The only bright line rule is that any tire made on or after 8/1/1968 was required to have the "permanent" molded in DOT marking. But that does not mean that some tires made before then didn't have the DOT marking. And I have seen irrefutable evidence that the start date for the DOT marking varied by tire manufacturer, and sometimes even by tire model from the same manufacturer. When the DOT statutes were adopted, and the regulations then issued, the mandatory start date for including the DOT marking was later, and then the deadline was pushed off a couple times so as to give the manufacturers time to comply. And even when the rules finally became effective stickers and tags were allowed to be affixed to tires (in lieu of molded in data) for a period of time to allow even more time for mold alteration.

But some of the manufacturers were able to be compliant well before the deadline, with altered molds, so they went ahead and added the markings before the deadline. Same for anyone making a brand new tire design in between the initial regs and the deadline - it would have made no sense not to go ahead and include the markings in the new molds rather than omitting them first and then having to change them again before the deadline.

That's a long winded way of saying there is no hard and fast date for when the DOT marking actually began for a given tire mfr. (other than all tires made on or after 8/1/1968 should have it). But below is a summary of Tire marking regs timeline to give you some guideposts:

9/9/66 - Effective date of "National Traffic and Motor Vehicle Safety Act of 1966". Tire regs were required to be issued on or before 9/9/68.

7/22/67 - Proposed tire regs issued, with initial proposed effective date of 1/1/68 (later extended - see below).

10/14/67 - Additional tire regs issued.

11/16/67 - Final tire regs issued requiring DOT mark (effective dates and deadlines below).

12/15/67 - Tire marking requirements were amended, effective 1/14/68. Deadlines did not change. (Note that on 4/11/68 and 5/29/68 the Tire regs were amended again, effective immediately, but the markings requirements were not changed by those amendments, so they did not change any of the markings deadlines below.)

1/1/68 - Effective date of all the 11/16/67 + 12/15/67 Regs, EXCEPT:

- 4/1/68 - Effective date of tire markings requirements, EXCEPT:

--- 8/1/68 - Deadline for tire mfrs to comply with "molded in" permanent tire marking reqts (affixed stickers or tags were allowed to be used from 1/1/68 - 7/31/68).

Cheers!

[Starship]

All tires, regardless of manufacturer, made after Jan. 1, 1968 were marked D.O.T. Early '68 could have come with non D.O.T tires.

[jeffschevelle]

Originally Posted by Starship

All tires, regardless of manufacturer, made after Jan. 1, 1968 were marked D.O.T. Early '68 could have come with non D.O.T tires.

Curious, what source materials do you have to establish a 1/1/68 date?

Again, what I set out above is DIRECLY FROM THE ORIGINAL FEDERAL REGULATIONS. The Regulations that established what the markings had to include, size of the font, etc., and the deadline of 4/1/68 (not 1/1/68) were not even issued until 11/19/1967. Again, some mfr's could have and perhaps did get the mold revisions done in 42 days, but not all of them.

And again, the Regs specifically granted an exception allowing tags or stickers to be used until 8/1/1968 in lieu of putting the marking physically on the tire. If you read the preamble to the regulations, that concession was added at the request of tire manufacturers who said the 4/1/68 deadline (not 1/1/68) for the tire markings was going to be too burdensome to meet.

I seriously doubt tire mfr's spent a ton of money to lobby DOT to grant them an extension from 4/1/68 to 8/1/68 if they were already marking ALL their tires on 1/1/68.

And I have two original Firestone Wide Oval spares that were mounted on March and April (respectively) dated 1968 Chevelle wheels that do NOT have DOT on them.

[Starship]

My source was the NCRS judging guide.

[jeffschevelle]

Originally Posted by Starship

My source was the NCRS judging guide.

OK, thanks. They must have only looked up the "effective date" of the overall set of tire and wheel specs regulations that contained the tire marking rules, without bothering to actually read all the tire marking rules to see when they were actually required to start. Also must not have read the rule about stickers and tags being allowed until 8/1/68, or the preamble to the final Regs that discussed the mfrs' various requests for delays, and the accommodations that DOT put in place as a result, extending the deadline to comply with the marking rules well past 1/1/68.

[Mr70]

My apology Mike,I was wrong when I said yours is 100% a reproduction tire.I now believe you have a real 50+ year old RWL tire there.
When I said tread design,I was comparing yours to this original redline Firestone tire I've had in storage that shows 8 tread valleys.I always thought it was an original Firestone F70-14 RWL up there,but could only see it's tread design and nothing else.Untill I removed it this weekend and see now it's really an F70-15 Firestone Bias-ply Redline tire,not a 14" RWL at all.
Sorry about that,and you have a very nice find that I wouldn't mind owning.
This it what I was comparing yours to.

[jeffschevelle]

Originally Posted by Mr70

My apology Mike,I was wrong when I said yours is 100% a reproduction tire.I now believe you have a real 50+ year old RWL tire there.
When I said tread design,I was comparing yours to this original redline Firestone tire I've had in storage that shows 8 tread valleys.I always thought it was an original Firestone F70-14 RWL up there,but could only see it's tread design and nothing else.Untill I removed it this weekend and see now it's really an F70-15 Firestone Bias-ply Redline tire,not a 14" RWL at all.
Sorry about that,and you have a very nice find that I wouldn't mind owning.
This it what I was comparing yours to.

The tread difference you are seeing has nothing to do with the size of the tire. That is the 67 model year to 68 model year FS Wide Oval tread. FS redesigned their Wide Ovals (sidewalls and tread) at the beginning of or during the 69 model year when they went to their new fiberglass belted tire design.

67-68 FS W/O's have all the writing inboard of the stripe. Early 67's had the stripe WAY out close to the pavement. That resulted in minor curbing incidents tearing up the sidewalls (due I assume to the fragility of the area on each side of where the stripe was cut into the outer layer of the sidewall). There is a Technical Service bulletin that says if a customer complains about a damaged sidewall then the dealership should give the customer 4 new FS tires.

FS's first step to try to fix the problem was to move the stripe inward -- all the way up onto the hump at the widest part of the tire cross-section. This happened some time before late June of 67.

Obviously that was not a great idea either since that part would be the first thing to get snagged on any taller curb. So that did not end the problems. So FS moved the stripe in even more to get in inboard of the center hump of the sidewall. That looks like the version you have.

Then for 68 they moved it in even more. But that cut off the bottom of the V and the A in OVAL making it unclear what it said.

[**] So then they revised the outer sidewall (but not the inner) to put Wide O Oval in line instead of stacked, which allowed moving the stripe in even more. That happened some time before mid March of 1968. Also when that change was made "Nylon" was changed to "Nylon Cord". But the back (black) sidewall on these tires looks just like a 67. The first iteration of these have no DOT marking. (See [**] below)

That basic design survived for some period of time past the 8/1/1968 molded-in DOT marking requirement, as I have seen some of those without DOT and some with DOT. But it appears that when the DOT marking was added "Nylon Cord" was changed to "Polyester Cord", and Deluxe Champion was added to the sidewall. I have only ever found this version on Mopar wheels, but assume they were used by GM too.

Then they finally gave up and redesigned the entire tire some time during the 69 model year (perhaps at the beginning?), going to the fiberglass belted SUP_R_BELT name with new side walls and tread, and with all the writing outboard of the stripe allowing the stripe to be much closer to the wheel. That is the tread design on the OP's tire, and is the tread on the Coker repros as well.

[**] As to the discussion above about the start date of the DOT molded-in marking, I found proof that what I said in the earlier post was correct - Original spare in an 06C 1968 Chevelle, on wheel dated 6/11/1968, which is the version noted at the [**] above, has no DOT marking, but DOES have a STICKER on the tread with the DOT 147 and all the info the DOT regs required !!!

So this falls in the time frame between 4/1/68 and 8/1/68 when the required DOT info could be put on a sticker or tag and not molded into the tire. And proves the timeline I posted.

I have to get the pics off my phone and onto the computer to post here, I will add them soon.

[Mr70]

Interesting info Jeff,so my FS Redline was molded after June 1967,up till about Feb. 1968?

Here's a few more pics..(Sorry to steal your topic Mike)

[jeffschevelle]

Yours has the stacked Wide O Oval (older style), AND Nylon Cord (second style). So that might be yet another step in between two of the styles that I described, that I have not yet seen on a 14" tire.

Or maybe the 15" sidewall had a little more room for them to play with on the stripe so they didn't have to unstack Wide O Oval to move the stripe in farther ?? I must admit to not paying as close attention to 15" tires as I have to the 14's, since all my cars came with 14's.