Does anyone drive with bias-ply tires?

[Roger]

Me too! Apologies to you, EV.

 

[blueskies]

Unfortunately, I don't have a lot of good memories of bias ply tires. They wore badly, and required frequent replacement - especially when one did not have the money or skill for proper maintenance of suspension parts. My first Healey, back in the late 60's, came with bias ply tires. I recall one long road trip of 1400 miles, as a broke student, when several tires gave out and my wallet was nearly empty. Scouring a pile of tires on the side of the highway, placed there to cushion the tracks of a crawler tractor as it crossed the pavement, paid off by yielding several tires of close to the right size. They made it about another 500 miles. At the time, radial tires were those new-fangled tires that rich kids had on their newer Healeys with roll up windows.

 

[Rob Glasgow]

Ah those days of being always short of cash. I relied on recaps for my first two cars. Arround $10-15 each as I recall and could only afford one at a time. I still remember the day when I finally had a real job and could afford 4 brand new tires at the same time. I knew I had finally arrived. No recaps since then. Just today I priced 4 new tires for my pickup. $800!
man have times changed. But I wouldn't want to go back to being a broke student....

 

[RAC68]

Hi All,

Although I have not driven on "Cross Ply" Dunlop RS5 since my car was new, I must admit I had the most fun with them and often think of driving through the forest reserve of Pike County, Pa and drifting around turns at speed over newly paved roads. As a City boy with little experience or even cognizance of the risks posed by wild life when fast driving at night on mountain forest roads, these tires tracked well and could be control-broken and provided that experience I purchased my Healey for.

As all good things come to an end, first my girlfriend (later my wife) informed me that the lights in the forest were eyes and deer and other animals could make short work of our well being. The second was the speed at which the tires wore and needed replacement. Since Radials were the present, I chose to replace my RS5s with Pirelli Cinturato 165R15s over the same size Michelin X. As a result of that radial purchase and the non-practicality and eventual disappearance of the Dunlop RS5, I look back on those initial drives with fond recollection.

As I understood, Cross-Ply was the method of RS5 construction. However, although I believe Bias-Ply came later, many refer to all non-radials as Bias-Ply. Am I correct or in error?

Ray (64BJ8P1)

 

[Editor_Reid]

As I understood, Cross-Ply was the method of RS5 construction. However, although I believe Bias-Ply came later, many refer to all non-radials as Bias-Ply. Am I correct or in error?

Ray (64BJ8P1)

From wikipedia:
Bias tire (or cross ply) construction utilizes body ply cords that extend diagonally from bead to bead, usually at angles in the range of 30 to 40 degrees, with successive plies laid at opposing angles forming a crisscross pattern to which the tread is applied. The design allows the entire tire body to flex easily, providing the main advantage of this construction, a smooth ride on rough surfaces. This cushioning characteristic also causes the major disadvantages of a bias tire: increased rolling resistance and less control and traction at higher speeds.[11] This outdated technology is still made in limited quantities to supply collector vehicles.[12] It is possible to fit older cars with modern tires, if historical authenticity is not paramount.

 

[RAC68]

Editor Reid,

Thank you for your reply. I had read Wikipedia's description prior my posing the question but somehow remember in the late '60 or early '70s the introduction of Bias-Ply construction. I wonder if it was with regard to the addition of belts as in Bias Belt tires? Either way, it was the construction of the RS5 that I referred to that gave great fun.

Thanks again and all the enjoyment you can handle,
Ray(64BJ8P1)

 

[EV2239]

As far as I'm aware there are three types of tyre, not two.

1. Crossplies are simply tyres whose carcass is made up of woven material whose main strands extend from the beads ones side to the other, not directly or perpendicular to the opposite bead but at an angle. There are several layers or "plies" of this material laid over each other so the plies are diagonal. Obviously a tyre built this way will be circular in section.

2. Bias belted tyres are crossplies as above, but with belting made of nylon or steel around the circumference under the tread. I'm not sure if the term Bias Ply applies to these or crossplies or both, but they can be low aspect ratio. They also work better than cross plies.

3. Radial ply tyres have the plies perpendicular to the beads, so the sidewalks can be quite soft and flexible. Under the tread and round the circumference is a belt as in bias belted tyres and it allows low section, wider than high tyres. The advantages are less internal friction and heat, so that a softer gripper compound can be used and a much bigger contact patch that means less wear even with a softer compound.

I expect everyone knows this and I'm an Englishman using English terminology and confusing things.

 

[Jim 58 BN6]

"I expect everyone knows this and I'm an Englishman using English terminology and confusing things."

Although not fluent, I learnt my first British English whilst reading through my TR4's repair manual, when I was 16 (and only weighed about 12stone6). The book had a dictionary to help clear up some of the confusion. I knew most terms, but I did have to look up big end bearings, gudgeon pins, dampers, and my favorite, nave plates. Though it was considered a maintenance task, I never had to de-coke my top end, but I once did have to offer up the cylinder head, to replace it after a valve job. I also centralised my carburetter jets, set the valve lash, and set the gaps on the sparking plugs.

Sorry, I learned to be a smart ass a long time before buying the TR.

Seriously, I completely understood and appreciated your explanation, and I'm sure you can correct some of my drivel! Jim

 

[HealeyRick]

Although not fluent, I learnt my first British English whilst reading through my TR4's repair manual, when I was 16 (and only weighed about 12stone6). The book had a dictionary to help clear up some of the confusion. I knew most terms, but I did have to look up big end bearings, gudgeon pins, dampers, and my favorite, nave plates. Though it was considered a maintenance task, I never had to de-coke my top end, but I once did have to offer up the cylinder head, to replace it after a valve job. I also centralised my carburetter jets, set the valve lash, and set the gaps on the sparking plugs.

Funny how much of us learned "British-English" that way. In the '60s with the "British Invasion" in the U.S. it was kind of cool to know some Britspeak. Thanks for the trip down memory lane.

 

[CLEAH]

Jim, what a great compendium of British repair manual speak! A fun read.

 

[Rob Glasgow]

I purchased a set of Goodyear (I think) fiber glass belted ties in 1970 for our 1967 Camero. They were still bias ply with a fiber glass belt under the tread. Suppose to be an improvement over the on belted tires. I don't remember if they handled any better but they lasted
30,000 miles which at the time was amazing. I now looking at tires that will last 70,000 to 80,000 miles. Progress is good.

 

[Jim 58 BN6]

I purchased a set of Goodyear (I think) fiber glass belted ties in 1970 for our 1967 Camero. They were still bias ply with a fiber glass belt under the tread. Suppose to be an improvement over the on belted tires. I don't remember if they handled any better but they lasted
30,000 miles which at the time was amazing. I now looking at tires that will last 70,000 to 80,000 miles. Progress is good.

Dad had a new '70 Mercury Cyclone that came with Polyglas tires (they may be the ones that you mention). They were a great improvement on previous tires, and might have been state-of-the-art in 1970, for that kind of car. My granddad put a set of Michelins (sold by Sears!) on his '65 Delta 88, sometime in the late '60s, and they lasted for many years.

When I bought my TR4 (ca.1977), it came with 4 bias-ply tires, the left rear was a whitewall. The car always seemed to take right corners better than left ones. It was a subjective thing, but I knew I noticed something. After working for a couple of months, I took the car to a discount place in the San Mateo area-might have been WD(?)-and bought 4, CF67 Pirellis (I think-they weren't P3's, they were their el cheapo radial of that time). I spent around $150.00, including mounting, balancing, tax and an alignment. It was a different car, not only due to the radials, but the guys at the tire place told me the whitewall was at least a size larger than the other 3. Three were metric sizes (165-15?) and the fourth was like D78-15, or some other ancient American size. I was positive that the car then handled equally in turns in both directions. I think it really did improve-a lot! Progress IS good!

 

[pan]

Many years ago a member of our local club got it in his head that because his 100-6 was originally supplied with what we call cross-ply tyres he should ditch his radials and fit new Dunlop cross-ply tires. What he didn't consider was that since the general adoption of radial ply tyres for high performance cars, tyre manufacturers had stopped supplying high performance cross plies, which is what Dunlop Roadspeeds were. I think he lasted about a week before they were replaced with radials! He reckoned that the car would change lanes without any input from the driver.
Jim, I don't think it is actually possible to wear out those old Michelin Xs. When I bought my 100 it was shod with those tyres. Some years later I met a fellow who had owned the car several years before me and the same tyres were on it then. By the time I became the owner they were so hard I reckon you could have driven a nail with them!

 

[EV2239]

I agree about those original Michelin X radials, they gripped well in the dry, not at all in the wet and on a 12/1300 Beatle they'd do 75,000 miles!

You our can still buy them, they're excellent now, don't last as long but better in the wet.

 

[Roger]

Jim, what a great compendium of British repair manual speak! A fun read.

Agreed, but I'm pretty sure valve lash is a term from the left side of the pond. Brits might speak of tappet or rocker clearance or gap.
I dont remember lash till alighting on these shores!

 

[Jim 58 BN6]

Agreed, but I'm pretty sure valve lash is a term from the left side of the pond. Brits might speak of tappet or rocker clearance or gap.
I dont remember lash till alighting on these shores!

Thanks. It's been a while, so I stand corrected! :redface-new: As a native Texan, maybe I can swap 'ya some Texas lingo for a more comprehensive British vocabulary?

 

[Rob Glasgow]

Jim, thank for the reminder. The Goodyears were called Polyglass. We liked the name well enough to name our then-new kitten Polly.

 

[bob hughes]

I drove on Mitchelin X's when I had my 100/6 - what a disaster in the wet - used to lose the back end at 5MPH around roundabouts in Bristol where I was living at the time - I was always wary about driving that car In the wet, especially with those tyres.



Bob

 

[EV2239]

Tappet clearance is what we say, but we're resigned to Americans modifying our language and making a very good job of it.

One of your greatest journalists HL Mencken is an excellent example, but I wouldn't dare quote his comments about presidential candidates in 1920. Google and chuckle but don't hit me.

 

[John Turney]

My 1970 Duster 340 came with E70-14 Polyglas tires. I discovered that they were the limiting factor in how fast the car would go when a sidewall blew out at >100 mph.