The relative benefits of a pull rod suspension

[JohnsonsEvilTwin]

Newey saying the pullrod 'doesnt add much' is nothing new from Red Bull.
It just deters others from doing it sooner.

The concept is that much more different to pushrod, and Red Bull is that much more stable at speed because of it. Of course it gives them more room around the rear of the car, allowing things to be placed lower within the car.

The W02 will probably have Pull rod rear, with EBD. I reckon so will McLaren, Ferrari and Renault too.
But what intrigues me to Mercedes is that they seem to be keeping a lid on things, but privately they appear to be very confident with what they have.

It marks a departure from 2010, when amidst all the fanfare people got lost with the reality that in January 2010, Mercedes GP was effectively half of Brawn GP.

The drum roll has started...lets see what Mercedes have in store, As I have said before I still expect the RB7 to be the class of the field, But the W02 will be closer to the RB7 than the W01 was to the RB6...Of that im certain or I will no doubt be one sad Alonso look alike at the German GP this year....

[PNSD]

Would there really be other benefits other than packaging for push or pull? Both are the same and should respond in the same way? I dont understand how one could provide more high-speed stability than the other when the same forces will be transmitted either by a pull or a push?

[JohnsonsEvilTwin]

I will source Scarbs explanation, as it is probably the best explanation on the web.

http://scarbsf1.wordpress.com/2010/10/1 ... odynamics/

Each have there benefits depending on the prevailing trends or rules. Basically, pullrod provides better centre of gravity.
Scarbs also makes mention that when F1 reverts back to the single diffuser for this year, the rear wing becomes more critical as does the air flow around the rear.
It was a huge reason why the RB5 was the only single decker to challenge the Brawn in 2009.

In terms of transmitting forces both will be near identical, but that is not the reason why you would change from one to the other.

[marcush.]

the trick with all this stuff is to get a decent leverage for the dampers and the spring ..but this is true also for the pushrod installation.
with all those links and bushings and bearings there is alot to be lost in installation stiffness as well so to simply say this one is better or that one is not the point .It always comes down how you are able to do the packaging and detail design to make it work as intended + let the guys do their work on it without breaking their fingers and arms not seeing what they do..
there is always one major reason for things to be done in F1 :AERO ,followed by weight and CofG ...

All teams have been crying around that front wing and forward third of the car is key to aero in F1 .
The main advantage of the pullrod at the rear can only be a better flow to the rear wing and bridgewing as the rear can be slimmer and lower at the cost of accessibility of dampers and fighting for room of the dampers in an area were you will find the clutch/bellhousing

[JMN]

Scarbs posted about it previously here viewtopic.php?p=93219#p93219. The packaging consequences are explained in better detail in the link agove, but there's another interesting point concerning traction.
I seem to remember a post digging into "How the rod is loaded in bump and rebound" and how it affected traction. I believe it was posted just after the Singapore GP, but I'm unable to find it.

[SiLo]

I'm more intrigued about whether this thing will have pull-rod suspension. Especially after Red Bull ran an illegal part on theirs, something to do with the angle of one of the rods I seem to remember.

[forty-two]

I'm more intrigued about whether this thing will have pull-rod suspension. Especially after Red Bull ran an illegal part on theirs, something to do with the angle of one of the rods I seem to remember.

Do you have any more info on the supposed illegal part?

I have a vague recollection of this, but can't remember the detail.

[Richard]

The RB problem was a strut that was profiled for aerodynamic advantage as opposed to neutral. Something to do with the pitch. Aerofoil shapes are allowed, but need to be horizontal. I gather the struts are still tubular metal, with the aerofoil CF stuck on afterwards.

I'm talking about the cross section, ie rotation as you look at it end on. The actual alignment of the strut in space can be anything you like, within the overall geometry of the car.

Talking of RB, they missed the first session last year. As did Brawn the year before them. Superstitious minds at McL? That brings us back on OP too!

[forty-two]

The RB problem was a strut that was profiled for aerodynamic advantage as opposed to neutral. Something to do with the pitch. Aerofoil shapes are allowed, but need to be horizontal.


talking of RB they missed the first session last year. As did Brawn the year before them. Superstitious minds at McL?

Aha! Yes that was it! Didn't the aerofoil shape also have to be vertically symetriccal so as to behave neutrally (as per camera mounts etc)?

Thanks Richard.

[myurr]

Edit: Richard's already posted answering whilst I was typing

If memory serves then it was the angle of the aerofoil on the pull rod that was at too great an angle, so they had to cut/shave that aerofoil off and run with a circular cross section until a new part could be made.

Either way I think the pull rod has gained a somewhat mythical reputation due to Red Bull's use of it. Whilst it has some packaging advantages and a small CoG benefit, to me it's not anywhere near as important as the overall aero or mechanical setup of the car. I wouldn't be surprised if several cars, including a front runner or two, were to stick with pull rods.

I'm much more interested to see if McLaren or one of the other teams has found another aero loophole to exploit, whether all the front runners will feature flexing wings, who does the best job adapting to the new tyres, etc.

[Richard]

Agreed. The pull rod probably has a bigger role in enabling other things to happen. optimum performance is often achieved with individual componants operating sub-optimally to give a whole greater than the sum of the parts.

The only "magic bullet" I've seen was the Brawn DDD in 09, when a single feature seemed to dominate everything else.

[ringo]

Edit: Richard's already posted answering whilst I was typing

If memory serves then it was the angle of the aerofoil on the pull rod that was at too great an angle, so they had to cut/shave that aerofoil off and run with a circular cross section until a new part could be made.

Either way I think the pull rod has gained a somewhat mythical reputation due to Red Bull's use of it. Whilst it has some packaging advantages and a small CoG benefit, to me it's not anywhere near as important as the overall aero or mechanical setup of the car. I wouldn't be surprised if several cars, including a front runner or two, were to stick with pull rods.

I'm much more interested to see if McLaren or one of the other teams has found another aero loophole to exploit, whether all the front runners will feature flexing wings, who does the best job adapting to the new tyres, etc.

Well i see it the other way. The pull rod is a massive aero advantage.
Look on the back of the rb6 on top the gearbox. look at how clean and low it is without the suspension parts hooked on.
It provides better cooling flow, better beam wing flow, and an opportunity to better shape the side pods and narrow the tail end of the the car with a narrower top side to the gearbox.

[wesley123]

On the other hand you are just preventing flow over the diffuser, so on that part there is nothing gained nor lost.

For next year, when Red Bulls crash box shape wont be legal anymore, an Pull Rod would make less sense, as you are having the space higher upwards due to the more regulated space, but you place it lower limiting flow over the diffuser.

[forty-two]

Why would Red Bull's crash structure shape be illegal next year?

Not doubting, just interested to know.

[ESPImperium]

Why would Red Bull's crash structure shape be illegal next year?

Not doubting, just interested to know.

Its sculped for aero purposes, they now have to be more or less a certain size and shape now.

http://scarbsf1.wordpress.com/2010/12/1 ... explained/