The relative benefits of a pull rod suspension

[myurr]

ringo, the pull rod is only prevalent at the moment because aerodynamically it's not in the way of where teams are directing the exhausts. It's not the silver bullet you have been arguing, and it's ludicrous to suggest that had Ferrari used a pull rod layout last year then they would have fared any better.

And to use statistics is a fallacy - correlation does not mean causation. Otherwise it would be demonstrable that global warming is due to the demise of piracy (a famous example of this).

For all we know with further research a team may work out a way to direct a centrally mounted exhaust down to the diffuser in a way where the pull rod gets in the way and thus switches back to the push rod.

Both solutions have their place in F1 depending on the rest of the aero concept, and I have no doubt that in the future at some point the championship running car will have a push rod.

[munudeges]

The current pull rod setup works well.

Does it? Their very obvious tyre, and especially front tyre, problems paint a different picture.

[xpensive]

I believe that for all practical and mechanical reasons, the push-rod is still to prefer, what's left is aerodynamic packaging speaking for the pull-rod and aero rules these days. But come 2014 with the turbos and their packaging, things could be very different.

[Crucial_Xtreme]

The current pull rod setup works well.

Does it? Their very obvious tyre, and especially front tyre, problems paint a different picture.

Yep it works well. All trackside observers & even the team say the front suspension & rear works well. Their tyre degradation issues are due to a lack of downforce more than anything.

[munudeges]

I beg to differ. The striking uneven wear that they've experienced at the front is not due just to a lack of downforce. There's some strange imbalance in that car. I question why you would change a working set up that most teams have used for the best part of twenty years in a place where there doesn't seem any pressing need to.

Would a rear pull-rod have helped Ferrari last season? I think it could well have done because it would have given them some clear space to work with aerodynamically given the regulations and in an area where they were struggling. That's really the only reason to use it, not that it is by any means the better solution or the one true path.

Come 2014 when noses will probably be lower then maybe it will be all change again, but Ferrari haven't gone for a low profile nose approach that would make this seem sensible right now. Certainly not at the front. To my mind it just introduces too many nasty variables.

[marcush.]

Sure insallation stiffness is going down with reduced size pullrod vs push rod that has to bear all the loads + anything that is transmitted through them when hitting a curb or having an offroad excursion.with the pullrod you are not relying on stiffnes in that situation but on tensile strength.

BUT when it comes to installation stiffness you sure would need more than a thin string and maybe the boffins would rather sacrifice stiffness for Aero...especially when there is not much else to find in terms of advantage..?

[ringo]

ringo, the pull rod is only prevalent at the moment because aerodynamically it's not in the way of where teams are directing the exhausts. It's not the silver bullet you have been arguing, and it's ludicrous to suggest that had Ferrari used a pull rod layout last year then they would have fared any better.

And to use statistics is a fallacy - correlation does not mean causation. Otherwise it would be demonstrable that global warming is due to the demise of piracy (a famous example of this).

For all we know with further research a team may work out a way to direct a centrally mounted exhaust down to the diffuser in a way where the pull rod gets in the way and thus switches back to the push rod.

Both solutions have their place in F1 depending on the rest of the aero concept, and I have no doubt that in the future at some point the championship running car will have a push rod.

It has nothing to do with exhuast. That is a straw man arguement. It never had anything to do with exhuast.
Where is your evidence. You use the words "for all we know", why should your speculation carry more weight than reasoning and statistics.

F1 uses natural law; the strong survive and the weak perish. It iterates and it rejects anything that has no use. Pushrod in the rear is such an idea.
There is no longer a place for it in F1, in the same way there is no place for leaf springs or coil springs, or steel rotors.

Passion in some fans is the only thing making the pushrod seem like it could return. That was Ferrari mistake last year.
If you think practically, you would simply eliminate what is inferior on the car.
who cares if it was good and reliable for 20 years? doesn't work the best then toss it out the window. Each team hopes to build the fastest car, they should be programmed to have no reservations for old keepsakes like a suspension type.

When i say no brainer, it clearly has to do with what a team needs to do to build the quickest car they can for the upcoming season. If you can't see why something is a no brainer then one may simply not be analyzing the situation in the right way.

Something is just better overall, be it aero, mechanical, current state of the grid shows that all teams got the memo, even HRT!

the onus is now on the pushrod backers to show why and how it can be reintroduced to the party.

[xpensive]

I beg to differ. The striking uneven wear that they've experienced at the front is not due just to a lack of downforce. There's some strange imbalance in that car. I question why you would change a working set up that most teams have used for the best part of twenty years in a place where there doesn't seem any pressing need to.
...

I have some problems with the pull-rod geometry of the Ferrari front, with such a flat angle forces will be xorbitant.

[myurr]

It has nothing to do with exhuast. That is a straw man arguement. It never had anything to do with exhuast.
Where is your evidence. You use the words "for all we know", why should your speculation carry more weight than reasoning and statistics.

F1 uses natural law; the strong survive and the weak perish. It iterates and it rejects anything that has no use. Pushrod in the rear is such an idea.
There is no longer a place for it in F1, in the same way there is no place for leaf springs or coil springs, or steel rotors.

Passion in some fans is the only thing making the pushrod seem like it could return. That was Ferrari mistake last year.
If you think practically, you would simply eliminate what is inferior on the car.
who cares if it was good and reliable for 20 years? doesn't work the best then toss it out the window. Each team hopes to build the fastest car, they should be programmed to have no reservations for old keepsakes like a suspension type.

When i say no brainer, it clearly has to do with what a team needs to do to build the quickest car they can for the upcoming season. If you can't see why something is a no brainer then one may simply not be analyzing the situation in the right way.
One should try to figure out how the "no brainer" guys got it right from so far back, so he can see that it's truly a no brainer.

What's so hard to appreciate? Something is just better overall, be it aero, mechanical, current state of the grid shows that all teams got the memo, even HRT!

the onus is now on the pushrod backers to show why and how it can be reintroduced to the party.

Why was the pushrod invented in the first place? The pull rod came first and was subsequently optimised into the push rod.

Are you seriously arguing that the advantages are so clear cut that the push rod should never have been invented and will never make a return!?!?

And F1 isn't just survival of the fittest, it's not as clear as that. Design is not optimised according to genetics, evolution, or computers. It is carried out by humans and emotional judgements are made. Why? Because F1 cars are not the pursuit of the fastest cars possible. Time, budget and human resource limitations coupled to our less than perfect understanding of the dynamics involved in an F1 car going round a track all lead to compromises being made. No F1 car is perfect and beyond improvement. There will be major shifts in our understanding in the future, and major changes in F1 cars and their design.

Finally it's ridiculous to suggest that the pull rod must be a no brainer because all of the cars on the grid now have it. With that line of thinking then Newey was a fool to reintroduce it in the first place as the rest of the teams were in consensus.

[Tim.Wright]

I have some problems with the pull-rod geometry of the Ferrari front, with such a flat angle forces will be xorbitant.

You arent looking at it properly. Tilt your head 35 deg to the side. You will see its a pretty standarad pull rod setup, just on the piss.

Tim

[marcush.]

I beg to differ. The striking uneven wear that they've experienced at the front is not due just to a lack of downforce. There's some strange imbalance in that car. I question why you would change a working set up that most teams have used for the best part of twenty years in a place where there doesn't seem any pressing need to.
...

I have some problems with the pull-rod geometry of the Ferrari front, with such a flat angle forces will be xorbitant.

I don´t see the sense of it.they rely on scrub (track variation) in suspension vertical travel to produce a bit of pullrod movement.Sure the tyres will warm with ease...I think they had better settled for a outboard rocker layout replacing the top wishbone and pullrod...I think there are better options for a high nose pullrod.

[xpensive]

I have some problems with the pull-rod geometry of the Ferrari front, with such a flat angle forces will be xorbitant.

You arent looking at it properly. Tilt your head 35 deg to the side. You will see its a pretty standarad pull rod setup, just on the piss.

Tim

Oh but I am, what's more I don't need you to tell me what is standard or not.

That flat angle will create enormous forces in the suspension which is likely to affect stiffness.

[myurr]

I have some problems with the pull-rod geometry of the Ferrari front, with such a flat angle forces will be xorbitant.

You arent looking at it properly. Tilt your head 35 deg to the side. You will see its a pretty standarad pull rod setup, just on the piss.

Tim

Oh but I am, what's more I don't need you to tell me what is standard or not.

That flat angle will create enormous forces in the suspension which is likely to affect stiffness.

Errr no. It's not the angle relative to the nose that is important, it's the angle relative to the suspension arms. When the wheel moves it will be producing the same forces and movement on the pull rod as in a design where the whole suspension was rotated slightly and the pull rod was no longer horizontal. It's visually confusing and I was fooled by it to begin with, but there have been numerous articles and posts by very well informed members that have set the record straight. And now that it's been pointed out to me it's easy to see.

[ringo]

Why was the pushrod invented in the first place? The pull rod came first and was subsequently optimised into the push rod.

You cant think cut and paste. Show me an old school pull rod torsion spring suspension in the REAR of an F1 car.
And then tell me what was optimised from that. If you can do that.
Saying something is much different than seeing something. You cant blanket all pullrod as the same.

I am clearly referring to rear suspension. So we can take it from there.
Also we can look at the motion ratios of each design. Pull rod has better motion ratio in 2 aspects.

[xpensive]

...
Errr no. It's not the angle relative to the nose that is important, it's the angle relative to the suspension arms. When the wheel moves it will be producing the same forces and movement on the pull rod as in a design where the whole suspension was rotated slightly and the pull rod was no longer horizontal. It's visually confusing and I was fooled by it to begin with, but there have been numerous articles and posts by very well informed members that have set the record straight. And now that it's been pointed out to me it's easy to see.

Don't agree, the angle of the suspension arms means nothing, unless you are thinking track-width widening with vertical movement. Other than that, isolate the vertical force on the upright and the reaction force from the shallow angle pull-rod.

Try think this way, what happens if I remove the pull-rod? Car falls down as the suspension arms don't carry load.

Pull-rod force will be vertical load on the upright over sinus horizontal-alfa for the pull-rod, when alfa becomes smaller,
pull-rod force goes xorbitant and stiffness out the window.