25 replies to this topic

[f1steveuk]

In the oft told story of slick racing tyres, it is always said that Mario Andretti was testing a new compound, but they hadn't had time to put a tread on them, and rather than wait, Mario was told to do a few slow laps, and instantly found them quicker. I find this a bit unlikely, the way tyres are manufactured the carcass would have gone in the mould complete with tread, because I cannot believe they hand cut EVERY tread. So what is the definitive story?? One for Doug I think

[Twin Window]

Originally posted by f1steveuk

One for Doug I think

Or one for the search engine, maybe...?

[David McKinney]

One for the "b......" file, I suspect

[f1steveuk]

Too many letters missing from B****** file for me to work it out!! If it's bullshit, then my argument would be, I have read it in several books (including Doug's) and Mario told me the same to my face when we were filming a technical doco for FOM. My problem is all my books are in France and I don't go home until Friday, so either someone beats me to it or I'll post it when I have found it and start the discussion again!!

[Graham Clayton]

In the oft told story of slick racing tyres, it is always said that Mario Andretti was testing a new compound, but they hadn't had time to put a tread on them, and rather than wait, Mario was told to do a few slow laps, and instantly found them quicker. I find this a bit unlikely, the way tyres are manufactured the carcass would have gone in the mould complete with tread, because I cannot believe they hand cut EVERY tread. So what is the definitive story?? One for Doug I think

Apparently the first slick tyres were accidentally discovered by US drag racers in the late 1940's and early 1950's:

http://www.mandhdragtires.com/history

[Tim Murray]

Their use by '40s/'50s drag racers is mentioned in these earlier threads:

Why was F1 slow to use slicks? (merged)

Slicks-Starting When?

They weren't the first, though, as those threads explain.

[Ross Stonefeld]

The origin story does seem illogical. Like Steve said isn't the tread put on in the factory? It's hardly an aftermarket product like snow-chains! And what would be the point of testing these incomplete tires, even for only a few laps?

[Cirrus]

Maybe the Mario story was given added credence by the (static) photographs of the 1966 F1 Ferrari on uncut tyres.

Edit - I don't know very much about the tyre making process as applied to racing tyres in the Sixties, but I would have thought that the tread patterns were moulded in rather than cut. As tyres got wider the job of cutting treads would have become more and more onerous if they were hand done. Maybe the tyre maufacturers made "blank" moulds in addition to the treaded ones to allow for some experimentation with tread patterns that were hand cut.

Edited by Cirrus, 21 March 2013 - 21:00.

[simonlewisbooks]

Long before WW2, Brooklands outer circuit cars often featured treadless(or almost in the case of the Railton..) tyres... do these count as slick or is it the melt-like-chewing-gum element that makes a 'slick'?

[Lee Nicolle]

F1 for all its hype is often way behind the times. They were still using wire wheels when many categorys were using alloy. They were on treaded tyres when others were on slicks, they used cross plies long after others used radials, wings were used long before they discovered them and in several other areas too. Seat belts, helmets and other driver apparel.
Really they copied other parts of the sport more than being copied.
This has been discussed on many other threads on TNF.

[arttidesco]

My problem is all my books are in France and I don't go home until Friday, so either someone beats me to it or I'll post it when I have found it and start the discussion again!!

Are you home yet ?

[Ross Stonefeld]

Maybe the Mario story was given added credence by the (static) photographs of the 1966 F1 Ferrari on uncut tyres.

Edit - I don't know very much about the tyre making process as applied to racing tyres in the Sixties, but I would have thought that the tread patterns were moulded in rather than cut. As tyres got wider the job of cutting treads would have become more and more onerous if they were hand done. Maybe the tyre maufacturers made "blank" moulds in addition to the treaded ones to allow for some experimentation with tread patterns that were hand cut.

Oh sorry, I misread the opening post. So the tire was 'finished' it just had to have the grooves cut into it. That's at least possible. Though I'm still not sure why you'd do even basic laps on them, if you thought you needed the grooves cut in what would you learn by going out?

[Ray Bell]

Yes, tyres are moulded with (or without) their treads...

Quite likely the suggestion that experimentation with hand-cutting of patterns meant they made treadless tyres, but the moulding process in which the strip of tread rubber that's laid around the outside of the carcase is heated to shape and cure it must by definition include whatever tread that tyre is intended to have.

That's basically the completion of the manufacturing process. Later hand-cutting is a different issue, of course.

[JtP1]

I have seen photos of Indy roadsters with slicks in the 50s with a single tread groove to measure wear. One of the things that bring slicks to the fore in circuit racing is surely the developement of rubber that produced the feel of treaded tyres from a slick. Looking at late 60s F1 tyres the tread is gradually reduced as the rubber is developed.
Dunlop had a dry weather racing tyre in the CR70 with small crosses for tread, but apart from Mini7s, who ever used them twice.

[f1steveuk]

Ralph, been home and traveled back a couple of times since I started this, didn't look as I thought the thread had died!

[Lee Nicolle]

Yes, tyres are moulded with (or without) their treads...

Quite likely the suggestion that experimentation with hand-cutting of patterns meant they made treadless tyres, but the moulding process in which the strip of tread rubber that's laid around the outside of the carcase is heated to shape and cure it must by definition include whatever tread that tyre is intended to have.

That's basically the completion of the manufacturing process. Later hand-cutting is a different issue, of course.

I agree. Most treaded tyres are moulded. Some wets however start as a slick and are handgrooved surprisingly. And most start with 4-5 rings moulded and the rest are cut. The same as many dirt tyres too
The original article about Mario may have some sense. IF [and probably a big if] they were doind a dvelopmental tyre that was supposed to have a heavier tread they may have done a batch of slicks so they could play with tread patterns.
Though by that time all race tyres were quite lightly treaded anyway so trying to handcut such a light tread may have been impossible.

[E1pix]

This may not apply at all here, but I recall Mario doing lots of tire testing for Firestone... including in F5000 in 1975, and for years at Indy according to local lore.

He showed up with a new qualie compound at Road America, in the Vels-Parnelli T332, which the track announcer technically categorized as "gumballs." Being a kid I just had to track them down and dig my fingernails into 'em — with permission from the V-PJ crew. I remember peeling them like they were wax.

[f1steveuk]

This is all a bit like "Mythbusters", and there is a basis to say it's plausible!

I've done many races on hand cut slicks, it's not an uncommon thing, so Mario (or someone else) may well have had some treadless tyres awaiting a pattern to be cut in, but I suspect we'll never know, who or when!

[Michael Ferner]

The major problem with the story is that slick tyres were already used for years before Mario Andretti even started racing!

Edited by Michael Ferner, 23 March 2013 - 16:23.

[f1steveuk]

The major problem with the story is that slick tyres were already used for years before Mario Andretti even started racing!

Mere detail!!

[alansart]

Slightly on topic. I've been doing some research for a painting I'm working on of Jochen Rindt's Lotus 72 at the 1970 Oulton Park Gold Cup. There were a few detail changes on the 72 over the season and one thing I spotted was that Rindt was using slicks for what appear to be the first time in a race. I must admit that I've not done an exhaustive search but I can't find photographic evidence to show he raced on them earlier. I believe the Gold Cup was Rindt's last race start as the next meeting was Monza....

[f1steveuk]

I'm going from distant memory here, but when I interviewed to Peter Warr for Gary Critcher, he spoke at length about Monza, and was fairly convinced Rindt's accident was caused by the mix of tyres, both compound and that the fronts at least were grooved, and were therefore, all at different heat values. Can't say I have ever seen a picture of the 72 on that last lap to confirm the grooves, but I am sure some one has pictures of both meetings to confirm?

[Tim Murray]

Rindt raced in the F2 event at Salzburgring between Oulton Park and Monza, so his last race start (and last win) was in Heat 2 of that race.

Edited by Tim Murray, 23 March 2013 - 18:03.

[alansart]

Rindt raced in the F2 event at Salzburgring between Oulton Park and Monza, so his last race start (and last win) was in Heat 2 of that race.

I didn't check F2 - Thanks Tim.

One forgets that the modern prima donnas are only allowed to race effone!

[Ross Stonefeld]

To be fair there's not a lot out there that would tempt them. Certainly not in the single seater realm, unless they really fancied the Indy 500.

Or better yet, a trip to Terra Haute.

[yulzari]

The pre war smooth treads were to give longer life not more grip. In fact they gave less as the surface was not divided into blocks that could move around separately to grip the surface. It is the use of smooth tyres to gain extra grip that makes the modern slick so we must look to the development of tyre rubber to guide us in when the modern slick began. Pre war hill climb cars used twin rear tyres to get extra grip by gaining extra surface area but with tread. In New Zealand the young Bruce McLaren is said to have used remould tyres with uncured rubber tread on his first (Austin 7?) racing car. 1950's dragsters had smooth treads but weak sidewalls so they had traction but not lateral grip. In the late 1950's came synthetic carcasses and flat crowned carcasses.

So, separately we have smooth tyres, extra surface area, flat treads and soft sticky rubber.

As with so many inventions the technology has to be in place before someone bright has a light bulb moment.

The true first slick road racing tyre would be ready in the 1960's. As to which and by whom may never be known. Once the technology exists frequently several people come up with the same idea as history shows us. I would like to think we can find out the first ones used in F1 though.