Where is the Anti Roll Bar located on a F1 car?

[marcush.]

not many cars with low mounted steering rack around in F1...

Brawn 2009,Renault 2010,Mclaren 2010...

[RH1300S]

Trying my best here with the pics...

Thank you!

I was putting too much emphasis on the link between the left and right sides, totally missing what happens when the third spring pivot can move to allow single wheel bump.

I had always assumed that the vertical post had to be the ARB - but trying the work it through from the pics, I convinced myself it couldn't work.

Now I can see.

Thanks again.

So the helper spring on the third spring is quite likely to be there to allow a little movement of the pivot post in single wheel bump before the third spring engages.

[scarbs]

Thanks Scarbs, nice pic!

Do you know wich car is it? Does it has an horizontal 3rd shock/spring? Are the pedals missing there?

I googled the picture, which was quicker than going through my archive of photos. Its a 2002 Renault and pretty typical of a front ARB installation, aside from Ferrari and the Brunner designed Minardis, that use a ingenious blade type ARB. Its lacking a heave damper, you can see the links on the rockers where it would fit.

At the rear most teams run a simple "U" shaped ARB, i.e. two levers on a torsion bar, the "T" type you see on the Renault only suits the old format of vertical torsion bars and lay flat dampers. As most teams now run ~horizontal torsion bars, with the ARB seperate from the heave damper. Interestignly soem teams have created an intermeidate linkage between the rockers and the ARB, I assume to alter the effective roll rate or add rising rate, McLarens one is pretty typical of this type and is also found on the FI.

[DaveW]

The top one, closest to the t-bar, appears to be a helper spring. Helper springs keep the sprung unit from rattling loose during extension, and are quite light in spring rate by comparison. This is likely a dual sprung unit, not a triple. IMHO

Perhaps. However, it would be a surprise if there isn't a bump rubber in the stack.

The issue (for me) is that the rate change(s) will happen suddenly (apart from the bump rubber). Sudden changes in rate wouldn't inspire driver confidence if they happened during a manoeuvre. No doubt, and with no road inputs, that could be avoided by careful "tuning", as RH suggested. In reality, however? Unlikely, I think.

Why not marry a single spring with a long(er) bump rubber, "tuned" with packers? Removes any requirement for a "helper", would probably reduce weight and would make rate changes smoothly progressive....

[autogyro]

I dont think that would work to keep the ride height acceptable with the DF changes with speed Dave.
As usual aero rules OK.

[DaveW]

I dont think that would work to keep the ride height acceptable with the DF changes with speed Dave.
As usual aero rules OK.

Mmm. I think you have it, auto. "Aerostatics" rules OK. Does work for LMP, GP2 & (some) F1 teams, however.

[marcush.]

The top one, closest to the t-bar, appears to be a helper spring. Helper springs keep the sprung unit from rattling loose during extension, and are quite light in spring rate by comparison. This is likely a dual sprung unit, not a triple. IMHO

Perhaps. However, it would be a surprise if there isn't a bump rubber in the stack.

The issue (for me) is that the rate change(s) will happen suddenly (apart from the bump rubber). Sudden changes in rate wouldn't inspire driver confidence if they happened during a manoeuvre. No doubt, and with no road inputs, that could be avoided by careful "tuning", as RH suggested. In reality, however? Unlikely, I think.

Why not marry a single spring with a long(er) bump rubber, "tuned" with packers? Removes any requirement for a "helper", would probably reduce weight and would make rate changes smoothly progressive....

why not throw away the steel spring altogether and just have a bump rubber with zero gap but a very low initial rate and progression ? got 800g of weight removed from the car instantly..

[autogyro]

That would suit the aero guys if the cars drove on glass but one bump and they would go airbourne.

[DaveW]

why not throw away the steel spring altogether and just have a bump rubber with zero gap but a very low initial rate and progression ? got 800g of weight removed from the car instantly..

Curiously, I've seen that solution. It's a question of load capacity, I guess, & the proportion of the load carried by the corner springs. For example, it probably wouldn't work with no corner springs (I've seen that solution, too).

[Just_a_fan]

why not throw away the steel spring altogether and just have a bump rubber with zero gap but a very low initial rate and progression ? got 800g of weight removed from the car instantly..

Something like that has been used previously - a stack of, effectively, dished washers used as a very stiff bump stop that also worked as a third spring. Not as ultimately compliant as a coil spring though.

I guess the issue is that the cars have a very large weight change in the course of a race compared to the refuelling days.

[DaveW]

Something like that has been used previously - a stack of, effectively, dished washers used as a very stiff bump stop that also worked as a third spring. Not as ultimately compliant as a coil spring though.

For the record, belleville washers. Compliance depends on how many & how they are stacked. Rising rate, "free" friction but tend to creep.

[mep]

Regarding the helper spring:
The point is that the two torsion bars for right and left side need to have quite some amount of compression when the car stands straight. They need this because during cornering the inside spring must be able to extend when the car goes into roll. Don’t confuse this issue with some pre-load you put only on the spring only (without the suspension actually moving) this is something different. To get the side springs compressed when you put the car on its tires you make the third spring a bit shorter. This is the amount the side spring can compress until the hard heave spring stops the movement. As speedsense already pointed out the heave spring then could rattle and bounce around so you put in a very soft spring who just keeps the things fixed together. I don’t think it will affect car behaviour in any significant way. Just remember the a-arm mounts are spring itself.

Side note:
Do you guys actually read my post on this forum? Many times I have doubts about it.
Scabs nice that this threat attracted your attention. You goggled for the picture, nice what search words you used? If you or anybody else has good pictures please post them. A good picture tells more than thousand words and there are many more interesting things to spot.
Things like the helper spring.

[marcush.]

tbh ,the word bump rubber is a bit too coarse then....with good shape(!) and the right shore + hysteresis you can subsitute almost the whole damper/coilover unit..

when starting of with bumprubbers I was not aware just how much you can do and what is available /possible with a peanuts worth of foam ..

http://smac.fr/files/pdf/smacbump-utilisation-GB-BD.pdf

[DaveW]

Regarding the helper spring:
Side note:
Do you guys actually read my post on this forum? Many times I have doubts about it.

Apologies, mep, I try. You could well be correct re the helper. However, look closely & you can see the the 3rd assembly comprises 3 springs, & (probably) a bump rubber.

[marcush.]

Regarding the helper spring:
Side note:
Do you guys actually read my post on this forum? Many times I have doubts about it.

Apologies, mep, I try. You could well be correct re the helper. However, look closely & you can see the the 3rd assembly comprises 3 springs, & (probably) a bump rubber.

with all that aluminium spacers involved thats quite a few parts there...and obviously they used that helper spring for taking up slack in the third spring ,otherwise they would have just increased the length of one of the aluminium adapters...right? such a triple spring setup has its own problems when it comes to chafing and rubbing ,eg.sideloads..
But the non lnearity is obvious and even more so because the secondare and third springs will go on block so we got a knee point in spring force ..not nice potentially.

btw this is a RedBull gearbox RB2 ?