Check Those Bias Ply's

Those are fiberglass belted bias, actually. 

Bias tires are more sensitive to inflation pressure than radials. Running them low on pressure causes them to heat up more than a radial would and the heat can damage the tire. 

I'm surprised that sticker doesn't say to increase inflation pressure by 4 PSI for sustained speeds over 60 MPH. Many stickers said to do that and it was common knowledge and convention to do so to keep the tires from heating up at high speed. I leave mine at the 60+ MPH pressure setting all the time so I can exceed 60 MPH any time I want without worry, I just deal with a little harsher ride at low speed. Still rides smoother than radials though. 

People stare are me funny at gas stations when I walk around the car and "feel" the temperature of each tire. You can pick out a bias tire low on air very quickly that way. 

FSJunkie wrote: I leave mine at the 60+ MPH pressure setting all the time so I can exceed 60 MPH any time I want without worry, I just deal with a little harsher ride at low speed. Still rides smoother than radials though.

Bias tires 'can' roll pretty smoothly,

as long as you don't count the first couple miles while they're working out the flat spots.

Short trips on any of the cold bias ply tires I've had were a good way to mix paint.

Thud Thud Thud

Whuuuuump-Whuuuump Whuump-Whuump Whump-Whump-wmp-wmp wp wp wp wp wp

after the first couple stop lights they'd end up half way between square and round and they would start to get better.

I spent many days putting new tires on, doing balance, alignment and more to make money for college and that sticker sure brings back memories. 

FSJ - note the bottom line "see manual for more information" or words to that effect........ LOL

But seriously, we drove pretty good sustained speeds with those pressures, no problem. 

I guess everyone is so used to radials and new technology, new WHEEL and TIRE sizes, new rubber compounds, that those stickers look foreign or all wrong. 

I eventually did convert my first Javelin to radials - and had to learn new pressures and other things when we first started selling them, but I put many many miles on the old school tires and honestly never had a flat, never had a problem. I had a couple of slow leaks - but I can recall plugging one, and patching the other - back when I also did that sort of thing.

Now if you want TIRE fun - work in a shop close to an Oscar Mayer plant - and get a call that they have an inside rear dual flat on their hair truck......... and no, the truck isn't empty.................
I also worked on bud wheels and other fun stuff - while getting dripped on............ 

My family owned a Western Auto store back in the 70s. We sold a lot of tires. After having to refund a customer who had bought a set of nylon truck tires, I always made it a point thereafter to tell anyone who wanted them that they would thump when cold. It's a tough material though, so good for work trucks.

Back in those days Michelin was one of the few companies making radials. I remember when the American manufacturers first started making them, and we put the first set we received on my mother's '73 Javelin. They made a huge difference in the ride and handling, and I've never looked back. I have some Polyglas bias ply on my AMX, but only for show. I have no desire to run them regularly any more than I would want to go back to using wooden wheels.

49 years ago I borrowed my Dads car to go get my flight physical before I joined the Army for flight training.  I was working on my own car, my 64 American,  and decided to take my Dad's 67 Falcon for the about 600 mile trip,  one end of Va to another.

It was about this time of year in 1969.  I was driving on the 4 lane during a  summer rain storm. Wasn't speeding, but was probably too fast for conditions.

I changed lanes in the middle of a slight curve, while driving over a bridge joint, the car whipped around faster than I could correct, and slid off the road backwards, into a rock bank.

 That rain and my road actions would have been no problem in my Rambler, it had radials, and I had been driving on radials about 2 years at the time.  But my Dad's car had bias ply tires,  which I didn't allow for.

As it was we finished the trip any how,  but couldn't get into the trunk to get our luggage, because the whole rear end sheet metal was crushed around the trunk lid. We both passed the flight physical, and both joined the Army on October 31, ( Halloween ) 1969.

That was my last highway accident,  I can't blame it completely on bias ply tires, but they were definetly a factor.