Ipso posted: " If the “lateral linkage” pivots by inflection from one wheel, it looks to have to affect the other wheel. I don’t see how it can’t – and I don’t see that as a good thing. The way I see it, the mechanism will increase chassis roll – not decrease it."

If scarbs is correct, and I'll bet he is, and there is some free play in overall rear ride height before the 3rd spring comes into play, one wheel can move in 'bump' approximately twice that distance before that wheel's movement would cause enough movement on the 'T' for the 3rd spring's free play to be used up and the other side to be affected, therefore I'm thinking that the effect one wheel has on the other happens rarely, if at all, due to the relatively small suspension movements on these cars; perhaps only when jumping curbs.

curvhog - 07 October 2009 11:46 PM

If it's any more help picture what is missing here that you find in almost every car and truck an anti-roll (sway)bar. If you look at roll bars they rest in bushings and only connect at each wheel. Rolling forces are transmitted to either wheel.

A better explanation is here:

http://en.wikipedia.org/wiki/Sway_bar

I initially thought the blue rods on ipso's 3rd photo were anti-roll bar links, but, noticing the wiring at the rear end of those rods, they may well be height sensors of some kind.........

wilmywood8455 - 08 October 2009 07:41 PM

Ipso posted: " If the “lateral linkage” pivots by inflection from one wheel, it looks to have to affect the other wheel. I don’t see how it can’t – and I don’t see that as a good thing. The way I see it, the mechanism will increase chassis roll – not decrease it."

If scarbs is correct, and I'll bet he is, and there is some free play in overall rear ride height before the 3rd spring comes into play, one wheel can move in 'bump' approximately twice that distance before that wheel's movement would cause enough movement on the 'T' for the 3rd spring's free play to be used up and the other side to be affected, therefore I'm thinking that the effect one wheel has on the other happens rarely, if at all, due to the relatively small suspension movements on these cars; perhaps only when jumping curbs.

But they are all directly connected. So practically, there is a rising rate of relative affect to the other wheel (based on link leverages) but no possible “platform” affect, whereby nothing happens to the other wheel until a certain amount of travel has been reached in the primary wheel.

Maybe I can buy an RC car (literally) and push down on it with my finger and see what is happening here. What did Matchett say last year: “moments of incidence”?

Conceptually, I think I totally have it down pat. I think I “know” what is supposed to be happening, but I just don’t see visually how the dominoes tumble.

It looks to me like the blue alloy rods are certainly primary telemetry.

So – ride height. My first thought is that the bar running from the wheel directly to the torsion lever (the green bit) – that bolt is not centered in the larger circle, and adjustment of that in/out (via spin) relative to the centerline of the car, seems to be a perfect place to adjust ride height, without affecting anything else. Looks like an interchangeable plug of some sort. It might actually have elastomer properties (since it is a different color – why is it a different color?)

Also – the exhaust shoots directly aft (dangerously close to the suspension). You would think they would shoot toward the center line, and directly toward a wing to enhance down force.

What is that finger on the right rear axel that has worn the ano off (or is that red “bluing” – reminds me of “metal shop” in high school). I’ll bet telemetry for actual speed.

On ride height if they use the same method on the rear as the front it's adjusted by different thickness shims on the pushrod. If you follow down from where the tuning fork shaped piece (Grey color) attaches to the torsion arm crank assembly it comes to a silver piece before it transitions to the black aero shaped push rod. The silver piece would be the removable shim. On a street car the torsion bars are indexed and you can pull the bar out and move it to a new spot to change the height. This would take way to long for F1 so my guess is the silver piece is a removable shim.

Axle speed is measured off that toothy looking piece on the shaft nearest to the gearbox. There's a silver colored sensor capable of counting teeth which is then translated into speed.

The finger on the shaft I can only take a swag that it contains a device to measure shaft deflection under load. I do see that it appears to be mounted to the rear a-arm so it would always maintain it's position relative to the shaft.

The blue rods could be to measure how much the the crank assembly is moving as reference to adjust shocks and other settings. Actual ride height I wouldn't be surprised if it is done with a laser to the road surface. During the Singapore race weekend Matchett highlighted one car going over the curbs and since it was at night you could see the red dot on the road from the laser measuring device.

ipso posted: "But they are all directly connected. So practically, there is a rising rate of relative affect to the other wheel (based on link leverages) but no possible “platform” affect, whereby nothing happens to the other wheel until a certain amount of travel has been reached in the primary wheel."

IF there were no 'free play' in the 3rd spring you would be correct; however, if there is, say, 1mm of free movement of the "T" in 'bump' before the 3rd spring makes contact and begins to add to the overall rear spring rate, the pull rod from one of the bellcranks can pull one side of the "T" (while the other side remains unchanged) 2mm before that 1mm 'free play' is used up and the 3rd spring is contacted.

To illustrate it, take two long thin items like pencils and arrange them in a "T", with the cross bar of the "T" equal lengths on either side of the upright part, and leave a gap between the two items of say 1/4". Holding the left end of the crossbar still, move the right end toward the upright part, closing that gap, and note how far that end moves before contact bewteen the two items is made. It will move about 1/2" before contact.

curvhog - 08 October 2009 11:38 PM

On ride height if they use the same method on the rear as the front it's adjusted by different thickness shims on the pushrod. If you follow down from where the tuning fork shaped piece (Grey color) attaches to the torsion arm crank assembly it comes to a silver piece before it transitions to the black aero shaped push rod. The silver piece would be the removable shim. On a street car the torsion bars are indexed and you can pull the bar out and move it to a new spot to change the height. This would take way to long for F1 so my guess is the silver piece is a removable shim.

Axle speed is measured off that toothy looking piece on the shaft nearest to the gearbox. There's a silver colored sensor capable of counting teeth which is then translated into speed.

The finger on the shaft I can only take a swag that it contains a device to measure shaft deflection under load. I do see that it appears to be mounted to the rear a-arm so it would always maintain it's position relative to the shaft.

The blue rods could be to measure how much the the crank assembly is moving as reference to adjust shocks and other settings. Actual ride height I wouldn't be surprised if it is done with a laser to the road surface. During the Singapore race weekend Matchett highlighted one car going over the curbs and since it was at night you could see the red dot on the road from the laser measuring device.

Shims: check!

About the toothy piece around the axel – I was wondering what purpose that could possibly serve. I was thinking you would only need a single tooth to calc axel speed, but relative to anti-stall and gear shifts and such, you would of course need more granularity. Surprising that isn’t internal/protected though.

Now that I think about it (with a more sober eye) of course you can have link leverages whereby nothing happens for a while as one wheel moves through the suspension. (I’m reminded of Spiralgraph/Rube Goldberg/my Amp crimp tool… PISTONS!)

“Laser measuring device” – hummm. How did I miss Matchett talking about lasers?!!? I guess lasers are fine for telemetry only – as long as it doesn’t provide a feedback loop to any kind of active suspension – which I believe is categorically banned.

(Dare I mention that – risking throwing yet another thread into a tailspin of slumping remorse and regret for lack of “true” technology in F1. Wikipedia is showing Colin Chapman as the creator of the first application of active suspension, with Lotus in the 80s, so that goes into the category of what F1 has brought to the road car. I’m a victim of marketing (or maybe just young age). It thought it was GM.)

wilmywood8455 – I never did know what a bellcrank was, until your mention prompted me just now to look it up. A prime example of what I was calling “link leverage”.

And – I must admit – I had no idea what you were talking about in “free play” later on (nor scarbs earlier on), until I pulled out two pens and now can “see” it. That is exactly what I was talking about when I said “platform” (which is a term used in mountain bike suspension – the 5th Element). Maybe “tiered” is a better general word.

So…

Relative to coil spring metal – as scarbs mentioned above (and confirmed elsewhere) – McLaren use hollow Ti springs. And thank you speedsense for introducing to me the notion of Rockwell testing. A fine example of “bracketing” technique, I might add.

Ah, the toothy piece. Since the picture is of an R26 from 2006 traction control was still legal and the more information the system had the happier it was. Somewhere else there were other sensors picking up actual road speed and front wheel speed to relate to rear wheel spin. You will find similar sensors on street cars with traction control and also as part of anti-lock braking systems.

I can't remember whether the laser bit was during practice or the race. I suspect practice because the teams will sometimes install instruments to collect data for setup and then remove them before the race.

curvhog - 07 October 2009 11:46 PM

If it's any more help picture what is missing here that you find in almost every car and truck an anti-roll (sway)bar. If you look at roll bars they rest in bushings and only connect at each wheel. Rolling forces are transmitted to either wheel.

A better explanation is here:

http://en.wikipedia.org/wiki/Sway_bar

Well, the "bar" may be missing, but not the "anti roll".

Take a look under your car and chances are you'll see that the normal springs are coil type and the anti roll bar is a transverse torsion bar.

This F-1 suspension is just the opposite. The regular springs are torsion bars, as pointed out earlier in this thread, and the linkage we're all looking at in picture #3 is, in fact, the anti roll system.

Study and follow the linkage and you'll see how it works just like the system on your car. The big difference is that changing the anti roll stiffness requires that the engineers only change one small springs, not a big transverse bar.

Plus, this fancy linkage allows the use of dampers which function on the anti roll part of the suspension ONLY without effecting the damping on the "normal" springs.

It's all very cool, nicely packaged, and makes one wonder how much the pivot point bearings cost because with all this linkage the total play would quickly get out of hand unless the individual parts are very close to perfect, (read VERY costly).

Spring rate variance/feel are (I’m told) one of the major reasons backup bikes/cars don’t seem exactly the same as the primary, even though they are, ostensibly, exactly the same machinery. Even springs that measure exactly the same for total weight (which is never), they will still have different rates through the spring/weight curve.

I wonder how fine-tuned the springs are in F1 – and how nonsymmetrical the spring rates are from track to track, left to right (primary & anti-roll).

We may finally have some direct comparisons to NASCAR!


In past years there seemed to me to be way more front wheel camber. I’m thinking in like ~05 and Kimi. Somehow it’s less dramatic now. Maybe the effect is now contained within the front suspension articulation. I suspect you would want the front wheels as flat as possible, to acquire and maintain heat – for the no-downforce formation lap if nothing else.

I guess it’s still there.


Funny example of years prior.

Mozella - 11 October 2009 11:38 PM

curvhog - 07 October 2009 11:46 PM

If it's any more help picture what is missing here that you find in almost every car and truck an anti-roll (sway)bar. If you look at roll bars they rest in bushings and only connect at each wheel. Rolling forces are transmitted to either wheel.

A better explanation is here:

http://en.wikipedia.org/wiki/Sway_bar

Well, the "bar" may be missing, but not the "anti roll".

Take a look under your car and chances are you'll see that the normal springs are coil type and the anti roll bar is a transverse torsion bar.

This F-1 suspension is just the opposite. The regular springs are torsion bars, as pointed out earlier in this thread, and the linkage we're all looking at in picture #3 is, in fact, the anti roll system.

No it is not. The coupling in the center of the down tube of the "T" bar is a pivot point. If that did not exist, then yes the bar would be a sway bar, as it would attempt to twist the top of the t and function as a sway bar.
The configuration in the picture has zero roll resistance, except in the two springs connected to the rockers/bellcranks

Study and follow the linkage and you'll see how it works just like the system on your car. The big difference is that changing the anti roll stiffness requires that the engineers only change one small springs, not a big transverse bar.

The third spring, like the T bar, also offers 0 roll resistance and only has an effect on squat/dive directions.

Plus, this fancy linkage allows the use of dampers which function on the anti roll part of the suspension ONLY without effecting the damping on the "normal" springs.

The main reason for the system, is to allow for the four main springs to control roll/individual wheel movements WITHOUT also having to control pitch (either direction) movements. By isolating the movement control allows the four main springs to be a lower rate (by removing the pitch controls) and having the pitch control isolated into the third.
In some cases would also include a third shock as well. Some systems also used only a third shock (with no spring control) as an isolation of the shocks control areas.

It's all very cool, nicely packaged, and makes one wonder how much the pivot point bearings cost because with all this linkage the total play would quickly get out of hand unless the individual parts are very close to perfect, (read VERY costly).

The amount of play is minimal and the tolerances are very close. The hiems and pivots are of a high aircraft quality, and as close to perfect that is possible.
Play in the system can also be reduced (if they wanted to) by preloading the third spring. Preload is setting the spring by compression by closing the length of the spring by winding the center rod piece closer together (when the car is on a setup table) allowing it to "act" further into the spring rate. For instance if the spring was a 100lb spring (1 inch of compression equals 100lbs). A preload of .5 inch, would mean the spring will "start" it's resistance at 50lbs instead of 0.