140 replies to this topic

[GeorgeTheCar]

How did that get out without a massive failure that pitched Rubens into the wall?

Someone here must be able to give us a theory!

[Tony Matthews]

How did that get out without a massive failure that pitched Rubens into the wall?

Someone here must be able to give us a theory!

Probably because it controls heave, so the rear of the car would drop a bit, but still be supported on each side by the main suspension units, which look like torsion bars to me. It is a similar system to that used by Ferrari at the time that Ross Brawn was a key team member, but I don't know how many teams currently use a similar system. The wayward spring runs horizontally across the top of the gearbox.

Edited by Tony Matthews, 26 July 2009 - 20:25.

[carlt]

Probably because it controls heave, so the rear of the car would drop a bit, but still be supported on each side by the main suspension units, which look like torsion bars to me. It is a similar system to that used by Ferrari at the time that Ross Brawn was a key team member, but I don't know how many teams currently use a similar system. The wayward spring runs horizontally across the top of the gearbox.

The errant item that struck Massa has been 'identified' as different things by different people
On the BBC broadcast it was called a torsion bar by Coultard , Eddy J produced a coil spring , when questioned Ross Brawn said it was a 'leaf spring'

This would explain Jensons mid race radio transmission , crying out in frustration that the car was so oversteery

[GeorgeTheCar]

The errant item that struck Massa has been 'identified' as different things by different people
On the BBC broadcast it was called a torsion bar by Coultard , Eddy J produced a coil spring , when questioned Ross Brawn said it was a 'leaf spring'

This would explain Jensons mid race radio transmission , crying out in frustration that the car was so oversteery

I can't see the connection between Barrichello's Saturday event and Button's race day issues

Edited by GeorgeTheCar, 26 July 2009 - 21:50.

[DOF_power]

Active suspensions, as used by Williams, eliminated springs, dampers and other stuff.
From I've heard they where banned to reduce costs and improve safety.

Look how that turned out ?!

[carlt]

I can't see the connection between Barrichello's Saturday event and Button's race day issues

The last car I had with independent rear suspension and a 'leaf spring' was a Triumph Herald
That would swap ends if you so much as farted mid corner

[Tony Matthews]

The last car I had with independent rear suspension and a 'leaf spring' was a Triumph Herald
That would swap ends if you so much as farted mid corner

Serves you right for being so anti-social!

It was a small coil spring, or at least, smaller than the one EJ produced, but you still wouldn't want to hit it at 150 mph or whatever. It had nothing to do with Button's problem. The CGG of the rear end of the Brawn, seen several times on the BBC transmission, show the coil in question. I think you may have mis-heard 'leaf' for 'heave'. If needs be I can scan a pic tomorrow of a similar system.

[tristancliffe]

The errant item that struck Massa has been 'identified' as different things by different people
On the BBC broadcast it was called a torsion bar by Coultard , Eddy J produced a coil spring , when questioned Ross Brawn said it was a 'leaf spring'

Typically F1 cars use torsion bars in the rear suspension as part of the springing medium. Coulthard probably just knew the initial report was about a spring and assumed it must be a torsion bar.
EJ was correct, as the onboard footage clearly shows it's a coil spring.
Was RB's comment before or after it was confirmed as a coil spring? If before then maybe it was his laymans' term for a flexure fitting?

Active suspensions, as used by Williams, eliminated springs, dampers and other stuff.
From I've heard they where banned to reduce costs and improve safety.

Look how that turned out ?!

Active didn't remove dampers or springs.

The were removed the slow the cars. It worked. Had Active continued then the cars would be a helluva lot quicker than they are now - too fast for circuits with gravel traps a spectator could see over. So in that way it DID improve the safety. Its banning had little to do with any of the accidents or fatalities that occured since. It might have improved Senna's situation, but not necessarily avoided the accident that killed him.

[carlt]

Serves you right for being so anti-social!

It was a small coil spring, or at least, smaller than the one EJ produced, but you still wouldn't want to hit it at 150 mph or whatever. It had nothing to do with Button's problem. The CGG of the rear end of the Brawn, seen several times on the BBC transmission, show the coil in question. I think you may have mis-heard 'leaf' for 'heave'. If needs be I can scan a pic tomorrow of a similar system.

My attempt at being light hearted amidst all the hot air -----

[Tony Matthews]

My attempt at being light hearted amidst all the hot air -----

I thought you were just blowing in the wind...

[Tenmantaylor]

So tech guys, a 1kg steel spring at 150 mph (67.5m/s) hits a restrained solid helmet. What kind of force was exerted? Mustve been massive. Try dropping a 1kg piece of metal 1 inch onto your finger on a table and youll be wincing or drawing blood. That helmet, though badly damaged, did an amazing job at deflecting it.

Massa is lucky he is so short, had he been an inch or two taller the impact would have been straight in his visor with even worse consequences.

[DOF_power]

Active didn't remove dampers or springs.

The were removed the slow the cars. It worked. Had Active continued then the cars would be a helluva lot quicker than they are now - too fast for circuits with gravel traps a spectator could see over. So in that way it DID improve the safety. Its banning had little to do with any of the accidents or fatalities that occured since. It might have improved Senna's situation, but not necessarily avoided the accident that killed him.

The Williams active suspensions had no springs or dampers.
Cars still got faster even without active suspensions.

The reason they where banned had nothing to do with safety, they where pure political.

[Greg Locock]

So tech guys, a 1kg steel spring at 150 mph (67.5m/s) hits a restrained solid helmet. What kind of force was exerted? Mustve been massive. Try dropping a 1kg piece of metal 1 inch onto your finger on a table and youll be wincing or drawing blood. That helmet, though badly damaged, did an amazing job at deflecting it.

Massa is lucky he is so short, had he been an inch or two taller the impact would have been straight in his visor with even worse consequences.

Agreed. Its is very difficult to work out the force, probably simpler to compare it with cricket or baseball mass and speeds. Cricket ball weighs 150g, fastest speed measured is 100 mph, but it slows by the time it reaches the batsman.

Can't say I agree with your estimate of the spring's mass, that would be quite a big spring(I haven't seen a photo of the part).

[DaveW]

On the face of it, the loss of a rear third spring would require two failures (an end fitting and a spring platform).

Considerable pressure is placed on mechanical designers of all components used in an F1 vehicle to minimize weight (and ultimately strength), but a rear third is located both high and aft, neither of which is good for performance, so one would guess that the pressure on the designer of that component would be particularly high. His task is supremely difficult because the loads carried by the rear third depend upon the track surface, the driver (where he takes the vehicle), and the race engineer (e.g. how suspension loads are distributed between corner and third elements). Another can of worms would be opened if an inerter, rather than a damper, was being used to carry the spring.

I sympathise with the designer of the rear third because he probably feels responsible for Massa's accident, even though it was unlikely to have been his fault (for some combination of the possibilities listed above).

[Tony Matthews]

Agreed. Its is very difficult to work out the force, probably simpler to compare it with cricket or baseball mass and speeds. Cricket ball weighs 150g, fastest speed measured is 100 mph, but it slows by the time it reaches the batsman.

Can't say I agree with your estimate of the spring's mass, that would be quite a big spring(I haven't seen a photo of the part).

The spring must have had quite a lot of momentum in the same direction as Massa, as it had only been 'free' for a few seconds after parting from Barichello's car, and although it must have slowed somewhat by the time Massa arrived it wasn't stationary, hovering in the air at helmet-height. Ross Brawn said 'One or two pounds, about one kilo...' The impact damage to the helmet gives an indication of the size... I would guess about 125mm x 50mm, and might have been titanium, no doubt the actual numbers will be revealed in time.

[Tony Matthews]

I sympathise with the designer of the rear third because he probably feels responsible for Massa's accident, even though it was unlikely to have been his fault (for some combination of the possibilities listed above).

I suppose it could even be a missed or un-tightened nut or clevis-pin retainer - I have no idea how the unit is fastened on the Brawn.

[cheapracer]

Can't say I agree with your estimate of the spring's mass, that would be quite a big spring(I haven't seen a photo of the part).

Looks like a older motorcycle shock rear spring, surprisingly quite large.

The last car I had with independent rear suspension and a 'leaf spring' was a Triumph Herald
That would swap ends if you so much as farted mid corner

Besides the few million Chev Corvettes running around, then theres all the Datsun 1000's and Nissan Vannetes which are still being made with independent fronts and leaf springs.

[Tony Matthews]

Copyright TM

Ferrari F2000 'rear third', in this case Belville washers rather than a coil spring.

In the captured screen-shot you can see part of Massa's helmet, you can extrapolate the rest of the helmet from the visible arc, and the spring is at almost exactly the height it impacted at, that is how I guestimatted the size, That, plus the shot of the damage to the helmet. In fact I think I may have been a bit generous. He was certainly a very lucky boy, assuming that the impact was inevitable.

Edited by Tony Matthews, 27 July 2009 - 08:31.

[Greg Locock]

In the captured screen-shot you can see part of Massa's helmet, you can extrapolate the rest of the helmet from the visible arc, and the spring is at almost exactly the height it impacted at, that is how I guestimatted the size, That, plus the shot of the damage to the helmet. In fact I think I may have been a bit generous. He was certainly a very lucky boy, assuming that the impact was inevitable.

say 48mm OD, 8mm wire, 6 turns? 300g in steel.

Edited by Greg Locock, 27 July 2009 - 08:41.

[Tenmantaylor]

say 48mm OD, 8mm wire, 6 turns? 300g in steel.

Brawn himself said in a BBC interview the spring that spring was "a fairly heavy object, 1.5 or 2 pounds, about 1 kilo".

http://news.bbc.co.u...one/8169256.stm

[carlt]

Besides the few million Chev Corvettes running around, then theres all the Datsun 1000's and Nissan Vannetes which are still being made with independent fronts and leaf springs.

What has this to do with :- ' independent rear suspension and a leaf spring '

[ferruccio]

I suppose it could even be a missed or un-tightened nut or clevis-pin retainer - I have no idea how the unit is fastened on the Brawn.

According to reports it was a gradual failure, based on accounts by Barrichello. He reported that something was not right with the rear of the car I think since practice and probably the problem wasn't obvious enough to be identified. Does happen sometimes. In the Q&A report Barrichello said it didn't come undone. It broke completely in quali. I think Brawn stated that the spring weighed 800gm.

[HP]

There's the suspension and how it works, including the spring that got loose and bounced on the track and was collected by the unfortunate Felipe Massa.



Apparently the bolt that locked it into place broke and the spring worked itself free. It should be obvious, why Rubens could still continue with those parts missing.

Edited by HP, 27 July 2009 - 12:13.

[DaveW]

There's the suspension and how it works, including the spring that got loose and bounced on the track and was collected by the unfortunate Felipe Massa.



Apparently the bolt that locked it into place broke and the spring worked itself free. It should be obvious, why Rubens could still continue with those parts missing.

Impressive graphics, but I would be very surprised if it was accurate. Layouts similar to the F2000 illustrated by Tony Matthews (Post 18) appear to be the current norm (but with a coil-over, rather than Belvilles - ugh) for a couple of good reasons - weight & stiffness. Count the number of bearings & structure in bending between the third element & the rockers. The one disadvantage of the F2000 layout is corner damper packaging.

[cheapracer]

What has this to do with :- ' independent rear suspension and a leaf spring '

Millions of Corvettes drive around every day and have done for the last 45 years with "independent rear suspension and a leaf spring."

say 48mm OD, 8mm wire, 6 turns? 300g in steel.

That sounds right because I know a 1 meter length of 6mm rod is 220g.

Edited by cheapracer, 27 July 2009 - 13:39.

[GeorgeTheCar]

[quote] There's the suspension and how it works, including the spring that got loose and bounced on the track and was collected by the unfortunate Felipe Massa.

[quote]


Well the fact that it is a front suspension leaves it somewhat less than compelling

Edited by GeorgeTheCar, 27 July 2009 - 13:41.

[Tenmantaylor]

That sounds right because I know a 1 meter length of 6mm rod is 220g.

Dont you guys believe the man who designed the car?

[cheapracer]

Dont you guys believe the man who designed the car?

No. Greg and I are correct, it's as simple as that.

Thru some more exotic alloy it could only possibly be lighter.

[Dragonfly]

There's the suspension and how it works, including the spring that got loose and bounced on the track and was collected by the unfortunate Felipe Massa.

Well the fact that it is a front suspension leaves it somewhat less than compelling

Front?

[Tony Matthews]

Well the fact that it is a front suspension leaves it somewhat less than compelling

Well the graphics show the rear suspension, but it bears no relationship to the graphics that were shown on TV yesterday, purporting to be the Brawn rear-end, that had a similar system to the photo I posted, but with a spring.

[carlt]

Millions of Corvettes drive around every day and have done for the last 45 years with "independent rear suspension and a leaf spring."

ok - thats half way revised
so what has that to do with :-
' the last car I had ......'

[Tony Matthews]

ok - thats half way revised
so what has that to do with :-
' the last car I had ......'

Perhaps they are all susceptible to a mid-corner fart - I know I am...

[J. Edlund]

Well the graphics show the rear suspension, but it bears no relationship to the graphics that were shown on TV yesterday, purporting to be the Brawn rear-end, that had a similar system to the photo I posted, but with a spring.

The third damper layout shown in the Youtube video clip appear to be almost identical to the system raced by Renault in 2005

[Tony Matthews]

The third damper layout shown in the Youtube video clip appear to be almost identical to the system raced by Renault in 2005

But it doesn't bear any relationship to the CG video clip shown on the BBC - which definitely showed a transverse third element with a coil spring. As soon as I saw it, complete with longitudinal torsion bars angled down into the gearbox I thought 'Ferrari F2000', which is the latest F1 car I have seen in detail. Then a little light went on and I thought - Ferrari - Ross Brawn! However, this thread seems to be going the way of RC, so I am going to shut up until some facts emerge.

[ferruccio]

But it doesn't bear any relationship to the CG video clip shown on the BBC - which definitely showed a transverse third element with a coil spring. As soon as I saw it, complete with longitudinal torsion bars angled down into the gearbox I thought 'Ferrari F2000', which is the latest F1 car I have seen in detail. Then a little light went on and I thought - Ferrari - Ross Brawn! However, this thread seems to be going the way of RC, so I am going to shut up until some facts emerge.

I agree. I think the trend now is transverse third damper/spring. Still hopefully someone can share with us rear suspension pics of the Brawn car.

[Petervl]

from F1technical.net, the following topic : Brawn BGP001 aero-mech development in 2009



showing the current 'standard' layout including torsion bars the heave spring (and possibly interter?) and the ARB droplinks.

regards
Peter

[Tony Matthews]

Thanks Peter, at last, proper info.!

[ferruccio]

from F1technical.net, the following topic : Brawn BGP001 aero-mech development in 2009



showing the current 'standard' layout including torsion bars the heave spring (and possibly interter?) and the ARB droplinks.

regards
Peter

I think teams are all using inerters housed inside the heave spring. Always wondered whether the springs really need to be that large unless the size is actually dictated by the size of the inerter. I read the springs are hollow titanium.

[Tony Matthews]

I think teams are all using inerters housed inside the heave spring. Always wondered whether the springs really need to be that large unless the size is actually dictated by the size of the inerter. I read the springs are hollow titanium.

The heave spring is only adding to the resistance of the main springing medium, the torsion bars. I realise that is not a very technical way of expressing it, but I hope the meaning is clear! In other worsd, I assume it does not have to be particularly 'strong', as it is only in use in heave, or squat, when the torsion bars are also working. I'm blowed if I can think of the right word! Reristive? Compressible? Powewrful? Any way, perhaps the diameter is fixed by the minimum diameter of the inerter.

It is at this point that I have to ask what an inerter is. A type of damper?

It is a surprise to me that the basic layout is so similar to the Ferrari of nine years ago - and the Ferrari used a coil spring on occasions, not always Belville wahers.

[ferruccio]

The heave spring is only adding to the resistance of the main springing medium, the torsion bars. I realise that is not a very technical way of expressing it, but I hope the meaning is clear! In other worsd, I assume it does not have to be particularly 'strong', as it is only in use in heave, or squat, when the torsion bars are also working. I'm blowed if I can think of the right word! Reristive? Compressible? Powewrful? Any way, perhaps the diameter is fixed by the minimum diameter of the inerter.

It is at this point that I have to ask what an inerter is. A type of damper?

It is a surprise to me that the basic layout is so similar to the Ferrari of nine years ago - and the Ferrari used a coil spring on occasions, not always Belville wahers.

I agree that the spring does not have to be particulalry big and strong (low 'k' value). It's probably a lot weaker than it looks and it's job is supported by the torsion bars as well. Though this is true for heave(squat) control, the spring needs to resist aero loads which are significant. i'm not sure about the values in F1 but in another series, the total downforce generated on the whole car can easily reach twice the weight of the car.

Yes inerters are essentially dampers but 'mass' type dampers. Their specific role is actually to dampen the springing behaviour of the tyre's sidewalls. The 'inerter' is an evolution of the 'mass tuned dampers' which FIA banned a few years ago. It really does the same thing but because unlike the MTD, the inerters are lighter and are housed within the heave spring, and is deemed legal.

So who you see there is still some excitement left in F1 engineering

[jmorris]

I think you guys have it wrong: soft springs/torsion bars at each wheel improve roadholding especially in the slow corners, strong anti-roll bars keep everything flat & tire nearly perpendicular to the track and a very strong-stiff-hard rear 3rd-helper-heave spring maintains the correct aero/under-floor clearance in the fast bits of the track.

[Fat Boy]

As far as the rate of the spring, it's probably in the neighborhood of 1-4k lbs/inch. A wide range, I know, but relatively stiff (I have no first hand F-1 knowledge) I'd bet. That's kind of the idea of having it.

I'm curious if the spring was actually connected to the car. I can't conceive of how the thing worked itself free even after a couple bolt failures. It could be that they changed the spring before the run and a mechanic accidentally left it on the bellhousing or something. They put the lid on, roll out on track and start to run. RB is driving because there is still a spring in his suspension. The other one rattles around until it drops out of the back of the car. I'm not saying this is the scenario, but it's certainly possible and wouldn't be the first time something like this has happened.

[Fat Boy]

I think you guys have it wrong......strong anti-roll bars keep everything flat & tire nearly perpendicular to the track

I'd be surprised to find many rear anti-roll bars in an F-1 paddock. Fronts....maybe.

[ferruccio]

I'd be surprised to find many rear anti-roll bars in an F-1 paddock. Fronts....maybe.

They use anti-roll bars for the front and back like all other single seaters. See the 2 'drop links' at the top of pic (above the spring)? Those are connected to antiroll bars.

As for how the spring came off the car, I think the cap (right hand side of sping in pic) came apart suddenly after a supporting component broke. The spring had to be under compression and was suddenly ejected from the right side of the car. I don't think it 'dropped' out but rather ejected out with fair bit of energy and bounced on track. Barrichello commented that he lost rear ride height quite suddenly when he felt something break at the rear.

In the Willliams car below you can see how it is possible for it to come off the car despite the bodywork

Edited by ferruccio, 29 July 2009 - 04:58.

[Fat Boy]

They use anti-roll bars for the front and back like all other single seaters. See the 2 'drop links' at the top of pic (above the spring)? Those are connected to antiroll bars.

They'll have the option to run them, no question. In practice, though, I'd be surprised to see many actually used.

[cheapracer]

They'll have the option to run them, no question. In practice, though, I'd be surprised to see many actually used.

Hey FB, great to see you back from whatever dark hole you lurked and posting again

[ferruccio]

They'll have the option to run them, no question. In practice, though, I'd be surprised to see many actually used.

yes, thats true. depending on set up they may opt not to actually have the ARB in place

Edited by ferruccio, 29 July 2009 - 05:37.

[Tony Matthews]

I think you guys have it wrong: soft springs/torsion bars at each wheel improve roadholding especially in the slow corners, strong anti-roll bars keep everything flat & tire nearly perpendicular to the track and a very strong-stiff-hard rear 3rd-helper-heave spring maintains the correct aero/under-floor clearance in the fast bits of the track.

That sounds more likely than my initial proposition, thanks.

[Tony Matthews]

So who you see there is still some excitement left in F1 engineering

I'm delighted to hear it! I was slightly disappointed to see how 'ordinary' the Brawn rear suspension is, but I suppose a great deal of engineering has gone into ares such as the twin-clutch, seamless shift systems, which, unfortunately, you can't see. Peter Wright did consider an update to 'Formula One Technology', I was keen to add new or modify old illustrations, but the project stumbled when those teams that were contacted were adamant that we would not have access to the most interesting areas of design. Ho hum.

[ferruccio]

I'm delighted to hear it! I was slightly disappointed to see how 'ordinary' the Brawn rear suspension is, but I suppose a great deal of engineering has gone into ares such as the twin-clutch, seamless shift systems, which, unfortunately, you can't see. Peter Wright did consider an update to 'Formula One Technology', I was keen to add new or modify old illustrations, but the project stumbled when those teams that were contacted were adamant that we would not have access to the most interesting areas of design. Ho hum.

Due to regulations, development seem to only be in the details. Their need for secrecy unfortunately remains until the tech becomes old news. Are any of the teams using 'twin clutch' systems now? Didn't know that. I though packaging would be an issue (3 shafts, wet clutch etc), assuming the regs allow the system.

The fact is an F1 car at the end of a season will always be heavily evolved compared to at the beginning of the season. I'm not sure if there is any other series with as much effort in 'in season' development as we see in F1.