Chevrolet SS wheel spare tire question

[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.