Brake bias adjuster?

Nobody knows then?

Edited by RS2000, 12 September 2011 - 16:09.

Edited by David Shaw, 12 September 2011 - 16:24.

Edited by Allan Lupton, 13 September 2011 - 17:34.

IIRC and I often don't, first time I heard of these devices was around the time of the Lotus 78 and Lotus 79 which would be around 1977/78, could Mario Andretti have been responsible for importing the idea from the USAC Champ Cars ?

I believe Ronnie Peterson was not a particular fan of these devices when he was driving for Lotus in 1978.

I am reasonably sure that Nelson PK was the first to use this idea in his Ralt RT1 Formula 3 car in 1978, why I remember this I do not know, I guess that is the way 50 year old memory works.

I dont recall those Lotuses using adjustable brake bias. They did use driver adjustable rear anti role bars and this was an idea introduced by Andretti.

Ya was wondren' was ya's?

Hard to say but with the massive fuel weight in the rear and skinny tyres of a 1937 Benz GP car it would come as a surprise if they didn't have something to compensate during the race - that's a logic based answer but Leif Snellman would know I reckon ..

http://www.kolumbus.fi/leif.snellman/

http://forums.autosp...p?showuser=3422

PS. Bauble, that formula is known to be accurate only when one knows how long is a piece of string.


Ah! Now that question has troubled mankind since time immemorial, even Iron Stein failed to crack the equation. The main problem is that while we all know that the piece of string has two ends, nobody has yet worked out the distance from one to 'tuther, and indeed if the distance varies according from which end you start your measurement.
I am of the opinion that the diameter of the string has no bearing on the eventual answer, but have no scientific basis for this believe. A well known US University tried to find the answer by cutting the string in half, measuring the two lengths and then adding the two together, however, this just multiplied the problem as they then had two pieces of string with no means of determining the length of either of them! Well it was a US establishment of 'learning'.

I suspect that the brake bias adjustment conundrum will never be unravelled until such time as the string situation is resolved.

Should any members of this forum find the science displayed here beyond their comprehension................. maybe they should consider the possibility they are just thick.

Edited by Bloggsworth, 12 September 2011 - 21:50.

Josh, although the regular posters on here know a lot about racing - car and driver histories etc, they aren't generally that hot on the technical minutae.

Edited by David Beard, 12 September 2011 - 22:03.

I dont recall those Lotuses using adjustable brake bias. They did use driver adjustable rear anti role bars and this was an idea introduced by Andretti.

Edited by Tony Matthews, 12 September 2011 - 22:31.

Oh dear, is that your impression, Duncan? We should all try harder then...

Sad reflection on the merits of TNF if you are correct.

Lotus 79 brake bias adjuster. Photographs of the first chassis being built don't show this, but I can't ascertain when it was added. There is quite a time gap berween my reference shots.

Is that driver-adjustable?

The formula for the bias v lift is simply 'pi x 0.5682 squared + the sum of the diameter of the offside front and rear side near wheels. Minus tyres of course.

Well, the Bowden(?) cable runs from the brake pedal assembly to a large knob on the dash...

Edited by David Beard, 13 September 2011 - 06:51.

Edited by 2F-001, 13 September 2011 - 07:25.

Well, the Bowden(?) cable runs from the brake pedal assembly to a large knob on the dash...

I find it strange that it wasn't mentioned in DSJ's description of the 79

Edited by 2F-001, 13 September 2011 - 09:01.

Of course, this will take a negative value in the southern hemisphere.

An article in Motor Sport, Dec 1979, said that the Ligier JS11 and the Tyrell 009 had driver-adjustable brake balance. It was an article about cockpit layouts and the fact that DSJ mentioned it for these two made me think that it was unusual He gave a detailed description of the Ferrari and the Williams without mentioning it.

Patrick Head was quoted as saying that the Williams didn't have driver-adjustable anti-roll bars as they didn't want the drivers fiddling as bout with that sort of thing.

The conventional brake balance bar was modified to accept a Smiths tachodrive connected to a knurled knob on the left-side dash frame, lower than the instrument panel. By winding this control to left or right the driver could juggle his brake balance as he pleased while in motion. With his front and rear anti-roll bar adjusters also available for fine tuning one could picture his controls as having more in common with an aircraft pilot’s than a road car driver’s.

re: anti-roll - Porsche 917-30 had the rear bar adjustable from the cockpit at the end of the 1973 season, but I don't know if this was something Penske had tried previously on another car.

Perhaps it ran back to the pits to allow Chapman to make the adjustment?

Seriously though, rather than a Bowden cable, wouldn't it be a speedo drive type cable?

I think you may be wrong, the diameter of the string will surely affect the degree of available stretch and therefore have a concomitant effect. The best way to measure a piece of string is to purchase a length of tarred rope, knot it at intervals and lay it alongside your string and cast across. I believe that a BSS guage is available from Buck & Ryan...

Well, the Bowden(?) cable runs from the brake pedal assembly to a large knob on the dash...

Seriously though, rather than a Bowden cable, wouldn't it be a speedo drive type cable?

Tim Murray. According to Doug in History of the Grand Prix Car 1966-85 the Williams FW07 had adjustable anti-roll bars and brake balance. From his description, the brake balance adjustment mechanism sounds the same as in Tony's Lotus 79 photos:

Edited by Tony Matthews, 13 September 2011 - 12:45.

Not new in 1973 but maybe it was for Penske: as I wrote in post no 7, Connaught used it in 1953

FWIW, Sal Incandela's book (pub. '82) merely states that cockpit-adjustable brake balance** was introduced "some years ago" (this is thinking in an F1 context). Sounds like the sort of think that Mark Donohue might have experimented with, although I don't remember a specific example from his book.

**Edit:
Apologies - I've revised the above: the reference in my first sentence was supposed to be in relation to Brake Balance (not anti-roll, which I originally typed).

re: anti-roll - Porsche 917-30 had the rear bar adjustable from the cockpit at the end of the 1973 season, but I don't know if this was something Penske had tried previously on another car.

Edited by doc knutsen, 13 September 2011 - 16:25.

AL10 had a device to enable the driver to adjust the roll stiffness, but not, presumably, through an anti-roll bar. Is such a device compatible with a de Dion rear axle?

Was it Salvadori or McAlpine who drove AL10 at Monza?

Edited by Allan Lupton, 13 September 2011 - 17:32.

Originally posted by xj13v12
The Mercedes Moss drove in the 1955 Mille had individual squirters for each corner to free up sticking brakes.....

Due, Pomeroy thinks, to their exceptional width, they had to be warmed up rather gently if cracking of the drum of the liner was to be avoided. For this reason one of the few instructions we had as drivers was not to use the brakes too hard at first, and not to worry if anyone campered by on the first lap or two as they could always be taken later. And believe it or not we also had some dear little plungers on the dashboard which fed oil into the brakes so that they would not be too fierce and lead to cracking.

In cars with rollbars where the bar adds stiffness it would be easy to make the input levers with controllably variable length,

Has that been done, Allan? It probably has, but I am only familiar with the 'rotating blade' type of lever.

Edited by Nigel Beresford, 14 September 2011 - 08:01.

Not exactly...

The squirters were installed in the W196 cars, possibly also the 300SLRs, but they might have had narrower drums so it would bear investigation.

Their purpose was to prevent cracking the ultra-wide brake drums in the warming up early laps of a race. Here's Moss' description of it from The Design and Behaviour of the Racing Car:

Did they use this on the M24 too Nigel?

Edited by Nigel Beresford, 14 September 2011 - 09:08.

The squirters were fitted to the SLRs at Le Mans, following some problems with grabbing brakes in the Mille Miglia.

The quote in Design and Behaviour is the only mention I know of their being fitted to the Grand Prix cars.

Since writing this, I have found them described in Setright's The Grand Prix Car. I could find none in Ludvigsen's Quicksilver Century, nor in Jenkinson's contemporary reports, which I would normally regard as definitive for these cars.

1975 McLaren M23 ...

Thanks


Nigel



(Image by Connect Images)

Than you, Nigel! I don't remember seeing that before, or on any other car! The blade system is, I think, a simpler, neater solution.

Edited by doc knutsen, 14 September 2011 - 20:15.