Finally had my 27 speedster done, drove it around the yard, etc yesterday.
Got home to this. A blow out while it was just sitting there. Cant believe it didn't happen when I was going through bumps in the yard or something.
Tire was aired to 37 psi. Balloon 21x4.50. I've heard anywhere from 35-40 is good. It's an Armstrong standard. Have not heard that name mentioned around here, but it's an old tire I'd guess 60s? Had light cracks going around it.
I'd assume what happened is that there were two slices in the bead (I do remember a few minor ones) and with the extra heat today, and an old tube, it just gave up. It had a flap too.
Have two new rims (two with bad welding repairs and were out of round needed to be replaced), all new lug nuts and bolts, new flaps, new tires, the works on the way. Better than it happening on the road, and for sure won't have any major wheel wobbling now from out of round rims and tires.
All these tire threads lately, figured I'd post this! Check your tires and tubes, if something's wrong, replace it and don't risk it. Glad it didn't happen when doing 45 on a two way road.
Probably age of the tires. Iíve had Sears Allstateís of the same era shred rubber. Your tire pressure might be 5 psi too high. Others will chime in on 37 psi in balloon tires
Casing failure only, or both tire & tube ?
George is right, 37 psi is a bit high. I run 32 psi in mine.
With today's heat in N.J., your 37 PSI could have increased to over 45 PSI ??? , plus age of casings and road stresses ???
I have our 26 Runabout inflated to 30 PSI, good book says 28 PSI.if memory is ok.
I don't know, just followed what a few people said was good. I was seeing a lot of 35-40 recommendations. I was honestly worried about the two front ones anyways, so glad this happened before I was going to town so nothing could get damaged.
Can you tell if the casing cord is cotton or nylon? Nylon cord tires will almost never blow out that way, even if fifty years old and age cracked (they can peel apart and go to pieces in other ways). Cotton cord tires can be a quarter of that age, have no visible cracking, and become so week that they will blow out at maybe even only half half that pressure. The problem is that cotton can develop a rot similar to dry rot in soft wood. It is a microbe that literally eats the strength out of the cotton.
I have a clincher tire from about 1970 that had almost no cracking showing, but could not be mounted onto a rim without breaking the clincher bead multiple times. The sidewall was so weak that I ripped it with my bare hands. And, no, I do not do telephone books.
Interesting. I'm pretty sure it's cotton now that you mention it. I'll check in a few minutes.
And the bead appears broken in two places. What is the condition of the wire in the bead adjacent to the fractures? I bet the rubber in the beads was damaged/cracked and water got in and rusted the wire while the tires were aging. Glad you are safe. jb
Yes James, it was broken in two places, maybe more. Both are getting replaced, and I'll have stricter used tire standards next time
I was wondering about the wire bead as well (clinchers generally do not have a wire bead). I have a 1927 Paige which the short story is my dad got it as the "great family project" in 1967, and it never got done. Eventually, it wound up in my garage taking up space, and I have had too many other higher priorities to get much done on it. The pre WWII tires on it one by one became unable to even roll the car on, so I bought some second hand tires for "rollers" at swap meets. It uses 20 inch rims/wheels, and tires. Not rare in that era, quite common on trucks for many years, but the truck tires were otherwise too bulky to be practical. And, they are unusual enough in the car sizes that decent rollers are hard to come by. But, I found a few.
One of the few I got, didn't work out however. Figured out, after the fact, that someone had used a modern tire machine to remove that tire from its old style rim. Whether the old style rim was a two (or three?) piece removable ring rim, or a split collapsible rim, I don't know. But it was NOT intended to have the tire stretched over the rim like drop-center rims are done.
The tire looked perfect, a little worn on the tread, but even it wasn't bad. No age cracking. I would have guessed it wasn't more than fifteen or twenty years old. I mounted the tire onto one of the Paige rims, aired it up to about thirty pounds, and everything looked fine. I went to push the car back into the garage, but about halfway in, KABLOOEY!!!!! A quick inspection showed the tire had stretched enough in circumference to lift off the rim and blow a new tube to smithereens.
A few days later, just because I am the kind of person that gets curious and wants to know "why?" I dissected the beads of that tire. There were about fifteen loops of steel wire run around and around those beads. All of them stretched until they broke inside the rubber bead casing. Apparently, after the tire was forcibly stretched off its previous rim, it shrank back to its original size and shape. Tire pressure stretched it off and away it went.
So, yeah, steel tire beads can be broken. But it takes a lot of force to do it. Some older tires did use cotton cord beads. Been a long time since I have seen one.