A bit of note about car tires in the early years

[Art Anderson]

Automobile tires would not have been possible without the advent of the process of vulcanizing rubber, of course. However, given that almost nobody on these forums was around when natural latex rubber was the only game in town, synthetic rubber, first made from coal, then quickly afterward, made from petroleum byproducts.

Latex rubber is milky in appearance, a fairly close cousin to the "milky" sap from the common milkweed that we in much of country see every summer, and once compounded with sulphur and a few other nasty chemicals, can be baked (vulcanized) to a fairly stable, yet soft and pliable material, it comes out a rather dark cream, or buff color. However, exposure to direct sunlight over time will bleach it out some, while at the same time breaking down the compound with cracks and also blisters of sticky, gummy residues which quickly dry out and crystallize. Anyone who has ever had a 10-speed bicycle from the early 70's to the early 80's will remember the cream or buff colored sidewall rubber on the tires--that was a band of natural latex rubber, over which, in the building up process, was overlaid with a strip of black synthetic rubber on which the tread pattern was molded in the vulcanizing process.

Around 1910, tire manufacturers discovered that carbon black, the very same powder as used in black printer's ink, when added to latex rubber, added much greater strength, in addition to reducing (but not eliminating entirely) the effects of ultraviolet light. This resulted in tires that while not truly black in color, were at least a very dark charcoal grey shade, due to the milky cream color inherent in latex rubber. This lead to the fading of tires upon exposure to sunlight, bleaching them out to first a lighter grey color, and in junkyards, or on cars abandoned out in the "north 40" on a farm eventually to an almost white, yet completely rotted color.

The confusion over the so-called "white tires", I have read, is due to the nature of not only the black & white camera film elmulsions used in photography before the more modern, and faster speed silver-nitrate elmulsions which became commonplace in the early 1930's, along with more primitive lenses. Those old cameras and the films they used exposed much more slowly, so bright sunlight reflected into them made for much greater contrast than those of a couple of decades later. This had the effect of darkening the colors on car bodies (even the fairly bright yellow of the 1911 Marmon Model 32 Inaugural Indy 500 winner appears to be very dark, which later black & white pics of the unrestored car taken in the 20's through the early 40's show that yellow as much lighter grey tones)while lighter colors often came out as if they were stark white. But, the process of pigmenting natural latex rubber pure white didn't come into use in car tires until the very late 1920's, and the advent of white sidewall tires.

So, pure white tires just didn't exist, they were rather, a cream color when new, bleached out in sunlight, had a very poor lifespan--in the early 1900's a tire might last as far as a thousand miles before the tread was worn through, or the woven cotton cord casing simply rotted and burst. Even black natural rubber tires were exceptional if one got 10,000 miles out of them, certainly something that would not be acceptable today!

Art

[Harry P.]

Given the poor quality tires along with the poor quality roads, I guess the average driver changed a lot of tires over the course of a year!

[sjordan2]

Thanks so much for taking this discussion to a new, dedicated thread. There are many of us on this board, and others, who are interested in these brass-era cars and have many questions relating to subjects like this. When we search for visual reference on vintage and classic cars, it's virtually impossible for anyone but experts to know what's original or the product of a later restoration.

[dwc43]

That's pretty interesting there.

I know this is kinda off topic to some degree, but there is one tire that I would like to know more about. The tires on the SR-71 Blackbird are not black like most plane tires. They cone in a grey color and have sintered iron metal filings throughout the tire to dissipate heat during high speed landings. Much like the filings found in metallic brake linings. Wonder what kind of rubber they are made out of in that grey color? If I am not mistaken, I think Good Year made those tires. I have a Revell 1:72 Bird sitting on the shelf, and it's a fav. plane of mine, so that is why I wondered about it.

[Modelmartin]

Given the poor quality tires along with the poor quality roads, I guess the average driver changed a lot of tires over the course of a year!

Try a week! When I went to Harrah's Auto Collection a few(cough) years ago they had a speedster brass era car there which I think was a Simplex. It had 4 spares mounted on the back! I had also read about the short life of tires and the completely routine punctures that had to be fixed, sometimes on every outing. But back then automobiling was a recreational activity for the wealthy.

Thanks for the history, Art. Since I do build brass era stuff the info is useful.

[Art Anderson]

Given the poor quality tires along with the poor quality roads, I guess the average driver changed a lot of tires over the course of a year!

I hesitate to ascribe "poor quality" to those early car tires, because in fact, they were probably as high a quality as could have been achieved. Rather, I would prefer using the word "primitive" as they certainly were exactly that.

On the other hand, not the same could be said for road and street surfaces of the era. Likely it was not at all unlikely for a motorist to have encountered a thrown horse shoe on a street, nails still sticking in it, and for that matter, if you have ever been around a farrier (he who shoes horses) often times they tend to bend over the sharp ends of a nail if it comes through the hoof, particularly on the toe area (forward facing hoof portion), so if one of those came out, double the danger on say, a brick street. Add to that the often careless street cleaning of the day--while much attention was made to remove the layers of horse manure, that was by scoop shovel mostly, perhaps spot sweeping with a broom, but street sweeper machines? Not yet, really (although many urban streetcar companies were under requirement to operate mechanical sweepers along their rights of way (the strip of pavement having the rails in it) as a condition of their generally exclusive mass transportation franchises.

On country roads, well not much more can be said--theyh likely had nasty bits of metal, even glass mixed into the dirt and the occasional gravel or gravel Macadam surfaces. Add to that the numerous bits of wood and other debris that might be barely buried and I think you can get the picture.

Those early tires were also quite high pressure--often as high as 80psi, which rivals bicycle tires of today (my mountain bike loves tires at 65psi for example. Those old tires started out with woven cotton fabric, often in layers (plies) upwards of 10 plies, as tire engineers had yet to discover the concept of bias ply cord casings. That is what forced such high pressures, as high psi was required to keep the casings from as much flexing as possible, in order to prevent overheating and failure of the casings. However, casing separation was a problem, especially once there was the slightest cut in the tread or sidewall, resulting in water and sand (or soil) being admitted, which forced its way between the plies of cording, thus creating a blister, a weakened spot that eventually would blow out (bicycle tires can still suffer this sort of blistering, BTW)

In addition, car weights were immense, when compared to the "footprint" of those often narrow tires--adding to the stress applied to them. Some cars, particularly the legendary and HUGE 1911 Oldsmobile Limited, put as much as 3 tons on tires like those, or 1500lbs per tire. With all that weight, it's little wonder that tire failures were so frequent, so common.

With the advent of the low-pressure (if 45psi can be considered low pressure today!) balloon tires by Firestone in 1925 (Peter DePaolo made them a household word when on May 30, 1925, he drove his 122cid supercharged Duesenberg to victory at Indianapolis), a huge step was made, as lower pressures meant that a tire could roll over otherwise puncturing objects with the rubber simply bending and flexing over the obstruction, thus eliminating what had been a true hazard. True, a nail or broken glass could, and did, puncture, many other bits of road debris became more of a non-issue.

Art

[Art Anderson]

Try a week! When I went to Harrah's Auto Collection a few(cough) years ago they had a speedster brass era car there which I think was a Simplex. It had 4 spares mounted on the back! I had also read about the short life of tires and the completely routine punctures that had to be fixed, sometimes on every outing. But back then automobiling was a recreational activity for the wealthy.

Thanks for the history, Art. Since I do build brass era stuff the info is useful.

By 1905, the automobile had ceased to be the exclusive toy of the rich, and began its much larger role as a utilitarian means of transportation, spurred on by the likes of Ford's Model C, the Oldsmobile Curved Dash, and the one cylinder Cadillac (long before Caddy became synonymous with luxury cars) along with a burgeoning number of other cars made at far lower prices than say, the likes of Packard, Peerless, Pierce and Locomobile. It was that expansion of the automobile's role in everyday life that made advances in such as tire design even more important.

Art

[charlie8575]

As always Art, very interesting and enjoyable. Thanks!

Charlie Larkin

[sjordan2]

Most of the spare tires I see mounted behind these early cars don't have spokes, just a tire and rim, sometimes two. I bet that made changing a tire on the road quite a fun experience.

[Art Anderson]

Most of the spare tires I see mounted behind these early cars don't have spokes, just a tire and rim, sometimes two. I bet that made changing a tire on the road quite a fun experience.

And for very good reason! In the days of wooden spoked automobile wheels, the wheel it self was semipermanently mounted to the axle or spindle, as its hub held the roller bearings which were, just as with cars today, tapered roller bearings for the most part, riding against equally tapered bearing races. Additionally, those old wood wheels were considerably heavier than the more modern steel disc wheels, which came into use (those mounting to a hub by means of lug bolts anyway), which would have meant serious work on the part of anyone attempting to change the entire wheel and tire out.

Those early car tires themselves used deep, clincher style rims, which gripped as much as half an inch into a corresponding groove or channel around the bead of the tire, and that made for an awful lot of oofing and grunting to pry such a tire off the rim--so, enter the demountable rim.

With demountable rims, the steel rim holding the tire and innertube was mounted to the wooden wheel (and the early flat disc steel wheels as well) by a set of 4-6 heavy steel lugs, which were formed to fit along the side of the "felloes", the sections of curved wood which formed the circumference of the wood wheel itself. That meant that the bad tire could be left on the rim once flat, whether that rim was on a wheel, or mounted to the spare tire mount itself. Thus the wheel-less tire and rim you see slung on a spare tire mount at the rear of the car is actually carrying a demountable rim.

Art