Does anyone drive with bias-ply tires?

[Michael Oritt]

Off of our thread about 48 versus 60 spoke wheels I thought I'd share this question: Does anyone now drive a Healey with bias-ply tires?

When I bought my 100 in 1999 it had recently come out of Bud Weikert's Blue Ridge Summit, PA restoration shop where it had a body-off paint job and an engine refresh. But the wheels were the original 48 spokers still shod with some 5.90 Dunlop bias ply tire. It had been about 35 years since I had driven an LBC, having had a series of BMW sedans in the 70's and 80's, and when I first drove the car with any vigor, especially over choppy roads, I was appalled at the way it stepped out on an uneven surface. But a set of 60's and the aforementioned Michelins changed things drastically and after further suspension upgrades (tube shocks, a heavier front and a rear anti-roll bar, etc) I consider the 100 a good handling car both on highway and challenging roads given the limitations of the steering and rear suspension.

In any case I started vintage racing about 10 years ago and though some folks use radials I have always used bias-ply tires--different rules for different cars so I have Dunlop 204's on the SR and Avon ACR 9's on the Courier and Ginetta--and my point is that I have really come to love the characteristics of these tires that break away so predictably and controllably, if on a racing surface.

I'm not giving up the Michelin XAS on the (street) Healey but simply wonder if anyone still uses bias tires and enjoys them? I don't mean for car show/Concours purposes but for actual driving? I'd probably find them a lot more acceptable now.

 

[BOBBYR]

Hi Mike ,
Sorry I don't have an answer for you , but that is a really good question . I would love to try a set of bias ply to see how much different my healey would act .
Bobby R

 

[EV2239]

Lethally, is how I remember them. My son has spent the weekend with the VHRA boys and witnessed a stunning forties Buick sliding into a Model A at 1mph on wet grass on a slope. The poor owner was heartbroken.

 

[Roger]

Wet grass on a slope? Would radials have been better? Town and Country maybe...

I'm curious to know how old were the tyres that the OP tried back in 1999? Age-hardened rubber is pretty lethal too.

I remember the change-over time from cross-plies to radial, 50s and early 60s. Some early radials, like Michelin 'X', provided long-life and economy but weren't as grippy as the best cross-plies. Racing tyres were mostly cross-ply for a while after radials became popular street wear. I realise it's not a fair comparison, but F1 didn't (Michelin excepted) really move to radials until the early 80s.

 

[Keoke]

Re: Does anyone drive with bias-ply tires?

Only if you live where there Are no freeways.--:highly_amused:

 

[Randy Forbes]

My Healey already had radials on it, Pirelli P3s, IIRC, when I bought it in 1978 (anybody remember those; great tire at only $32.00 apiece!). However, around that same time, I was privy to driving a Jensen 541R, and it was fitted with bias-plys. I don't remember their exact size, but they were mounted on 16" diameter knock-off steel wheels (the car also had an Austin 4.0 eng/David Brown g/box and 4-whl disc brakes). The tires looked to be barely 3-1/2" to 4" wide, and I well remember telling people that it would fishtail standing still!

Great fun driving the car around the city streets of San Francisco, and every 15-20 MPH turn in an intersection was a drift opportunity__in the dry!

I cannot remember driving another car since then running bias-plies. Probably a good thing.

Bummer about the Buick vs Model A

 

[59diamond]

On my previous Bugeye I put Bias ply white walls on it and I could really tell the difference when I was on a freeway that had grooves in the pavement. The white walls were not as wide as the radials that were on it before and the difference in width is what I think made the biggest difference in handling.
i would never put Bias Ply on my present Bugeye

 

[CraigC]

My Healey already had radials on it, Pirelli P3s, IIRC, when I bought it in 1978 (anybody remember those; great tire at only $32.00 apiece!).

I remember the P3 quite well. Went through a few sets in the 70's. Still have the last ones purchased on some old wheels in the garage. I was lucky in that my mom's best friend's son worked at Wholesale Distributors(they may have only been in the East Bay) and would hook me up with those tires at his cost.

Great fun driving the car around the city streets of San Francisco, and every 15-20 MPH turn in an intersection was a drift opportunity__in the dry!

I was always convinced that the paint used by the City for crosswalks and lettering was some sort of special paint/teflon mix. I learned as a kid not to ride my bike across that stuff at an angle!

 

[Randy Forbes]

I remember the P3 quite well. Went through a few sets in the 70's. Still have the last ones purchased on some old wheels in the garage. I was lucky in that my mom's best friend's son worked at Wholesale Distributors(they may have only been in the East Bay) and would hook me up with those tires at his cost.



I was always convinced that the paint used by the City for crosswalks and lettering was some sort of special paint/teflon mix. I learned as a kid not to ride my bike across that stuff at an angle!

Drifting a bit, from Michael's original question, but I can remember more than one (>1) New Year's Day spent standing in line at WD for some massive sales event. Once, including the tax, I bought four (4) P3s in 175/80 x 14 for about $112.00. Since I was buying them "loose", we were out of there pretty quick once we reached the guy with an order book.

The fun part was carrying them back home packed around my girlfriend in an MGB (the mounted spare and a couple new tires in the trunk, the others packed in beside/around her)!

 

[Editor_Reid]

My 100M had/has the repopped Dunlop Roadspeed RS5 tires, and I quite enjoyed the easy-drift characteristics, although I didn't push my luck.

My MGA has U.S. Royal Laredo tires in size 5.60-15 (bias ply), and I also enjoy those. I do make it a point to keep reminding myself that I'm driving on roller skates compared to radial ply tires though.

I've long thought it a pity that probably 99+ percent of Healey owners have never experienced a Healey they way they drove off the showroom floor. Radial tires make such a huge difference that it is virtually a different car, and it is a completely different "driving experience" with radials. Safer? Sure. But part of owning a vintage car is the vintage experience, at least for me.

 

[Rob Glasgow]

My first radials on the Healey were Pirelli Cinturanos. What a difference compared to the Dunlop Road Speeds that were on the car when I bought it. Although I always thought the car deserved English tires, not Italian.

 

[EV2239]

Dunlop racing tyres as used on D Type Jaguars to win the 1955 Lê Mans were radial

 

[Michael Oritt]

I'll applaud you from the sidelines on this one Reid as I can well remember the thrills of several times swapping ends--luckily without event--on my TR3 and later 3000 when I was a callow, invulnerable youth. True seat-of-the-pants driving in a controlled drift is a thrilling experience but these days I'll take mine on a race course.

BTW the Lime Rock Park Historic Festival is coming up September 2-5 and one of the entrants is 100 driver Rich Maloumian who always puts on a great show and finishes at or near the top of his group. It's a great sight to see him push his car around the track even if usually from behind.

 

[glemon]

When I got my 100 it had 5.90 x15 Dunlop "Gold Seal" radials, they looked a lot like the original Road Speeds. The tires looked good but we're old, and I remember being a bit scared when I took a bumpy corner at not much speed and still nearly losing it.

My first car was a 66 Sprite, bought used at the time when radials were still mostly fit to high end European and performance cars. Of course it had bias plies, but so did everything else I had driven up to that time. I got radials for it later, Semperit's that had recently won a Road and Track's or Car and Driver tire test. The difference was stunning, the car cornered and stopped much better. I remember the car felt like it cornered as well or better in the wet as the bias plies did in the dry.

I like to drive my hobby cars a bit, I think even if I had a set of bias plies they would be limited to on and off the show field for the most part.

But yes, the cars were designed around the performance of old skinny tires, I think a nice safer compromise between modern performance and vintage feel is to run your car on skinny radials. The absolute limits might not be as great but it will often feel lighter and more "alive" on 165s than a 185 or bigger, at least my 100 and 4A did.

 

[Roger]

Dunlop racing tyres as used on D Type Jaguars to win the 1955 Lê Mans were radial

No they were not, sorry!

 

[Michael Oritt]

I believe Roger is correct and while ai may be speaking out of court I don't believe that Dunlop made radials--even for the road much less the track--back then. Also consider that all vintage racing organizations require that Jaguar C's, D's and XK's race on bias-ply tires. I have only seen them shod with Dunop 204's--the same tire in a somewhat smaller size that I must use on my Elva SR. These are relatively narrow-section tires (60 to 65 aspect I believe) and it is eye-opening to see a D-type sliding along on these tall, narrow tires but that is the way they are supposed to be.

The thinking behind this requirement has less to do with historical correctness and more with safety--radials will stick a lot longer and so impose greater loads on suspension, steering, etc. components than will bias-ply tires which slide rather easily. This is how these cars were designed to be driven and the idea is to maximize forward speed while driving with a slip angle (drift) which allows the car to go fast without 100% forward adhesion. Radials are not designed to perform in this manner and they will stick, stick, stick and then break away rather suddenly.

 

[Roger]

The D-type had what became common later - corners by Dunlop.
Dunlop disc brakes, Dunlop aluminium wheels, and Dunlop racing tyres. The tyres in 1955 were R3, 6.50x16.
The "R" does not mean radial, it means racing, like subsequent tyres up to R7.

204 is a relatively modern tyre, to current regulations, but to be reasonably similar to the originals. Curiously, as far as the UK is concerned, 16in R3s (and others, but not the smaller diameters) are nowadays made in road-legal manner.

 

[EV2239]

As I said the racing tyres fitted to 1955 D Types for Lê Mans were radials. Not many know that.

I think the video explaining all and the dreadful accident is a BBC one and on YouTube.

 

[HealeyRick]

As I said the racing tyres fitted to 1955 D Types for Lê Mans were radials. Not many know that.

I think the video explaining all and the dreadful accident is a BBC one and on YouTube.

Interesting. Looks like the Dunlop "Stabilia" radial was developed specifically for the D-types. Here's some references:

https://www.hemmings.com/magazine/hmn/2013/08/Competition-Bred/3728521.html

https://www.jec.org.uk/mag/je072014/files/assets/basic-html/page81.html

 

[Michael Oritt]

Wow--interesting factoid and I certainly stand corrected.