26 replies to this topic

[Ali_G]

Why is that F1 car ran with such narrow tyres throughout the 50's and early 60's.

i just cannot understand it. Was there a rule specifying narrow tyres or something.

Niall

[Ray Bell]

Were they so narrow?

There was no precedent for widening them. It was all cutting edge stuff when they started making the tyres wider.

[Gil Bouffard]

It is also because, back in the Dark Ages of car racing, if a racing team didn't have a replacement part, they could scour the paddock for a car of their manufacture and purloin a part from an unsuspecting spectator.

Until around 1959, the tire companies made tires for racing which were very much like an ordinary street tire. Around that time some of them had come up with a skinny "rain," tire. Tread design being the difference. I've also seen photos of mechanics "shaving, " the tires.

Gil

[marion5drsn]

Tires used to be made out of cotton cords, just what year was it that they changed to nylon I don't know. Rayon was also used. All this had a great deal to do with the strength of tires. Michelin didn't perfect Radials until sometime in the fifties. M. L. Anderson

[Barry Lake]

The four-wheel independent suspension systems of the 1950s (Cooper for example) and the early 1960s had massive camber change on roll and would not have benefitted from wider tyres.

The development of more sophisticated suspension designs (limiting camber change) and of wider tyres went hand in hand from the late 1960s onwards.

[Ali_G]

Barry: Best answer so far anyway.

Why didn't they simpley stiffen the suspension up enough to handle these tyres.

i would have thought that any disadvantage would have been made up with the masses of new grip.

Niall

[Barry Boor]

There was nothing wrong with narrow tyres; that's all they knew and anyway 'if it ain't broke, dont fix it'.

[Ali_G]

It just boggles the mind. Simple logic would tell you that you would get more grip.

Niall

[oldtimer]

A not insignificant part of the camber changes that Barry referred was caused by chassis twisting under cornering loads. Colin Chapman reduced, but didn't eliminate, these factors when he introduced the space-frame chassis. Look at pictures of the early Lotuses - you'll still see some odd wheel angles.

But then Chapman took the next step with the monocoque chassis and we were on our way to evermore grip, aerodynamic aids to clamp the whole thing on the ground, carefully manicured surfaces so as not to disturb the low pressure centres under the car, and here we are.

Personally, I found the 'skating on rubber' thing more entertaining and awesome, particularly in the absence of gravel traps and run-off areas. I have seen a picture of Fangio at Monaco in 1956 in a full bore drift exiting the Tabac corner, with nothing to stop an error in his feel for the slip angles of his tyres but the stone wall.

This in contrast to a comment in another thread that 'any lame-o can slide a car'.

[Ray Bell]

I think the Lotus 18's crazy rear wheel angles were more a product of poor geometry...

But they weren't as bad as the 59/60 Cooper F1s, so your point is mighty valid.

Let's say that the suspension geometry advances of 1960/61 combined with better chassis understanding of 1958/60, allied to a more scientific approach in 61/62 led to the tyre width advances of 63/64?

[Barry Lake]

The "crazy" angles on the inside wheels were a product of the geometry they were using to try to keep the outside wheel as close to upright as possible. Camber gained on one side was "lost" on the other.

An associated problem was they sometimes lost more from the inside tyre than they gained from the outside tyre. (This still happens in certain sitauations with current cars).

The point about rough circuits is important. Those 1950s and earlier cars had to have a lot of suspension travel to cope with the bumps and jumps.

Keeping wheels upright is a lot easier on modern circuits with the bumps eliminated and very little suspension travel or body roll.

I'd like to see a 2001 McLaren or Ferrari trying to get around the 1950s Nurburgring quickly...

Another factor that hasn't come up is that in those days, before the development of really sticky rubber that "keys" itself to the track, engineers and designers were still working on the basic law of physics that increasing the tyre's footprint on the track did not increase the total pressure on that footprint.

In theory, there was nothing to be gained from using a wider tyre. And this was pretty much the case in practice, also, until "stickier" rubber evolved.

[Ray Bell]

I think we can put a time period on that... Dunlop were talking about high hysterisis tyres in 1961/62.

But Jim Clark ran through a large part of the 1963 season (five races, I think) on one set of tyres... or so the story goes. So they still weren't gumballs...

[mat1]

Originally posted by Ray Bell


But Jim Clark ran through a large part of the 1963 season (five races, I think) on one set of tyres... or so the story goes. So they still weren't gumballs...

Yes, I have heard that one too. But I don't believe it.



Concerning the width of the tyres: I think the difference is perhaps not that much as it seems, because (at least in the 50's) the wheel and the walls of the types were larger than afterwards. As a result, the footprint was possibly longer than now. Of course, this did not compensate for the lack of widt, but it makes a difference.

BTW, what pressure did they use then?

mat

[twymanj]

Today cars in historic racing run with wider tyres. My father thinks that because the cars didn't run with fat tyres in the day, they shouldn't run with them now.

http://www.motorsnip...ER_FORMULA2.htm

[Ray Bell]

Originally posted by mat1
Yes, I have heard that one too. But I don't believe it.

BTW, what pressure did they use then?

Fairly high pressures, around 40psi would be a good starting point, I think you'll find.

As for believing the story, it came out at the time, not later, so it would have been challenged if not likely. And it was, I think, stated in respect of a wet race at the end of the run, where the lack of tread had hampered Jim's progress.

Got to agree, twymanj, there is a lot of squeezing done to get wide tyres on narrow rims... but by the same token, I know of cars obliged to run narrower rims today than they had originally.

[Buford]

Well one thing about common sense is it does not become common sense until it becomes... um... common. Common sense would seem to be you put an upside down airplane wing on a car and it kind of pushes it down and that might make it go faster. But that did not become common sense until around the time humans were landing on the moon. Common sense would seem to indicate you shouldn't put the drivers feet out in front of the wheel line if you want them to walk normally for life, but that did not become common sense until a decade ago.

Common sense in the year 2020 would seem to be that... well we don't know. But whatever it is, we sure were stupid in 2001, weren't we?

[FlagMan]

Wider tyres mean more drag.

[Buford]

Also I think what really kicked off the wider wheels and lower profile tires was when Mickey Thompson brought the roller skate cars to Indy with little wide tires nobody else had in 1963. That kicked off a lot of pissing and moaning so the next year they banned them, but the wide tire idea genie was out of the bottle, because they seemed to work (well duh!).

Having to go to bigger diamater wheels in 1964 threw off the suspension settings and aerodynamics of Thompson's cars, and that probably is what caused the Mac Donald - Sachs crash horror. But because Firestone would not make wider tires for the roadsters, A.J Foyt went to Goodyear and got stock car tires (yeah in those days they were wider - lower profile tires) and then the poo poo really hit the fan. He ended up not using them in the race but wore a Goodyear patch on his uniform in Victory lane even though he used Firestones.

That kicked off the tire war and both Firestone and Goodyear started thinking and testing and spending tons of money and next thing you know, along comes common sense. And yes, there was a time before the twit that runs the place now turned it into a low tech spec car race that F1 took some of it's ideas from Indy, not the other way around as it has been, in the memory of those who grew up watching the 70's and later.

[Ray Bell]

Your Indy pitlane stories are always good, Buford, and I was trying to think of the trigger... and the Thompson car didn't come to mind... thanks for that. I remember at the time it seemed to make sense...

[mat1]

Originally posted by Ray Bell



Fairly high pressures, around 40psi would be a good starting point, I think you'll find.

Thanks, Ray.

And that would be around 1960? I have the impression the tyres became wider already in the first halp of the 60's, and I expect the pressure to become lower, of course.

mat

[Ray Bell]

Very much so...

[oldtimer]

Can anyone comment or enlighten on the effect of tyre width on slip angles? My understanding is that a tyre has maximum sideways adhesion when it it is at its slip angle, much the same as getting maximum braking at the lock-up point. This is the phenomenon that the early drivers used to exploit, and why we have those fascinating shots of cars head-on to photographers with the steering in a straight-ahead configuration.

My question is: is it easier to feel the maximum adhesion point with a narrow tyre than a wider tyre with stickier rubber?

[Eric McLoughlin]

I'm sure the jump from 1.5 litre to 3.0 litre must have had an influence on the growth of tyre width, especially the rears. BHP increased from arounf 250 to over 350 on 1966 alone.

[Don Capps]

I think we covered some of this in another thread or two long ago, but we often forget that the technology was not there in many cases. Buford is on the correct track about the Firestone 'rollerskate' tires that were used by the Thompson cars in 1963. However, the 1964 tires were called 'Sears Allstate' tires and actually produced by Armstrong if I recall.

The first 'wide' tires were the M&H tires produced for the rail dragsters in the late-1950's. However, there were a number of technical issues that stymied wider use of the tires. Once the problems of how to best design the carcass to support a wider profile were resolved, things began to happen, the Firestone 'rollerskates' being one of the earliest examples of this. Keep in mind that much of the design went back to the knowledge Firestone picked up from its own work on dragster tires. Keep in mind that these were also 'slicks' as we know them today and really radical to all of us back then.

In 1964, Dunlop introduced the R6 tires which were on 13" wheels and seemed so different from the R5 in is profile. In the US, Firestone also produced a much wider road racing tire and the clever folks at Chaparral were the first to grasp the opportunities they presented for re-looking at how to best set up the suspension of a car to use these new tires.

Clark ran the same set of Dunlop R5 tires in the Dutch, French, and British GPs. It was only three races, not five. Amazingly enough, the wear was consistent among all four tires. That speaks volumes about the uncanny knack that Clark had for taking car of a car.

In late 1965 and early 1966, Dunlop started looking at computers as to how to best find the solution for a wider racing tire. The R7 was the first tire they produced in which much of the design work was done using the computer. Prior to this, much of it was slide rules, alchemy, guesswork, and luck. How things change.....

[Buford]

Yes Don is right. Thompson's tires were "Sears" and one or more of the cars were Sears Allstate specials. I didn't mean Firestone made them. I didn't recall who did other than they were part of the Sears promotion. However, because Firestone would not make wider tires for the roadsters, Goodyear got involved after Foyt flew to Akron and walked in without an appointment and demanded to talk to somebody about making him Indy tires. That started the tire war that resulted in the major increase in tire technology, part of which was wider profiles.

[Buford]

To clarify further, Firestone was making wider tires for the Lotus, so it was not only Thompson's cars that had wider tires, though Thompson's were really, really wide. That is what pissed off the roadster guys. They saw Thompsons cars and the Lotus's cornering speeds and they thought more than just the rear engine configuration, a lot of their corner advantage was the wider tires. In other words, common sense was becoming common when they saw it in front of their eyes.

The roadster guys were pissed that Firestone was making wider tires for the damn foreigners and their "Pickle On A Roller Skate" and "Funny Cars" (where that name came from) but would not make a similar tire for their "real race cars". That is what prompted Foyt to flip out and go to Goodyear, which was then making a stock car effort and looking to get into the exclusive Firestone domain. They could not make new tires in May but they said, "Well hey A.J., why don't you try these stock car tires and we'll make you whatever you want as soon as we can."

So Foyt used them and liked them but was afraid to change to them for the race because he didn't know how long they would last and even though he was faster on the stock car tires, he opted for the conventional tires in the race. He wore a Goodyear patch though and that pissed off Firestone, who said, "Gee, we better rethink all this" and Goodyear was all "We better make A.J. happy because he is the Indy 500 winner and a promotional bonanza for us", and both tire companies over the next few years spent dozens of millions on tire technology. It even got so intensive that the two companies provided most of the funds to run the teams in the late 60's.

[Ray Bell]

There was a good article in Motor Sport maybe a year ago on the almost unnoticed transition to slicks, and the problems that they had to overcome before it could finally happen.

But Firestone had tyres that were virtually slicks about 1966, derived from their Indy stuff, afik.

This is apart from the major issue of tyre width...