FAQ |
Members List |
Social Groups |
Calendar |
Search |
Today's Posts |
#21
|
|||
|
|||
Bill, the history of tire sizing will tell you why the sizing change occurred for '65.
For '64, the "normal" aspect ratio was higher (IIRC roughly 82%). The tire sizing convention at the time was tire width (7.50) x rim dia. (14). The aspect ratio was a calculation based on the ht. of the tire from which you could derive the sidewall ht. in '65, there was a modest change to the aspect ratio (IIRC it might have gone to 78%), The sizing convention did not change but the decrease in aspect ratio meant the nominally same ht. tire now had a slightly wider tread. I don't know what drove the change in "normal" tire aspect ratio. It may have been an effort by the tire industry to standardize and possibly reduce the number of tire sizes manufactured. During that period of time auto and tire safety were under increasing scrutiny by the Fed gov't. Perhaps there was some effort made to increase the safety of tires that resulted in the change in the aspect ratio. Higher load rating may have been the reason. Whatever the case, the 7.50x14 was replaced for '65 by the 7.75x14. Later, a letter system was introduced, this size tire became the F tire size. In fact, even in '64, the F coding was already in use by GM for the 7.50 tire width for manifest coding purposes. Don't know what the J9189 could mean. There was/is an SAE Standard J1981 that was developed to standardize tire testing. But assuming you didn't post the wrong nos., I assume the code on your tire is unrelated. Seems to me there is a high likelihood that the tire that you found in your trunk in 1989 was original to the car. |
#22
|
||||
|
||||
Don't forget the
Snow Belt REDLINE option
__________________
When I die, I want to go peacefully like my grandfather did, in his sleep. Not screaming like the passengers in his car. Last edited by Jeff Hamlin; 02-26-2024 at 07:15 AM. |
#23
|
||||
|
||||
I'm sure plenty of those were sold in MN....
|
#24
|
||||
|
||||
Real Red Line
Official red line tire from Kansas City Plant. Contains air from Kansas City, Houston, Los Angeles, SF Bay Area.
|
#25
|
||||
|
||||
Real Red Line
More pics
|
#26
|
|||
|
|||
Quote:
I noticed your red is bleaching out too. Mine was fairly red back in the 70's but now is almost completely white with maybe a faint pink tint. |
#27
|
|||
|
|||
‘65 Red Line, correct?
Since the ‘65 tire had the lower aspect ratio vs ‘64, I’m guessing the ‘64 7.50x14 tire did NOT say LOW PROFILE on the sidewall. Can anybody confirm that? |
Reply |
Thread Tools | |
Display Modes | |
|
|