Illegal skid block tricks discovered

[FW17]

i still dont understand the point of the plank post 1994. It was introduced to prevent stalling on a flat floor. From 1995 onwards it is completely irreverent as the floor is not going to stall with the introduction of the stepped floor.

Teams would still run a plank even if they didn't have to. Cars bottom. Would you rather bottom on the very expensive and long lead time monocoque, or a sacrificial plank?

Carbon can sit on skids what ever size the teams choose

[AR3-GP]

i still dont understand the point of the plank post 1994. It was introduced to prevent stalling on a flat floor. From 1995 onwards it is completely irreverent as the floor is not going to stall with the introduction of the stepped floor.

Teams would still run a plank even if they didn't have to. Cars bottom. Would you rather bottom on the very expensive and long lead time monocoque, or a sacrificial plank?

Carbon can sit on skids what ever size the teams choose

https://a57.foxnews.com/static.foxnews. ... ?ve=1&tl=1

A carbon plank.

[vorticism]

Is was made clear to be in a IG post by scarbs yesterday, THE SKID BLOCK IS THE MEASURING POINT. Completely destroys any thought of using thermal expansion to protect them and shows just how clueless we all are.

Not quite. 2025 regs state:

3.5.9 f.: The plank assembly must have four precisely placed holes the positions of which are given by RV-PLANK. To establish the conformity of the plank assembly after use, its thickness will only be measured at these holes, regardless of whether plank or skid material is present.

They measure at the inspection holes regardless of what material is present. If it’s all skid, they say the skid is worn. If there is plank present, they say the plank is worn.

The specifics of the MCL39 and the general topic of this thread are not necessarily one in the same.

[venkyhere]

I read through the whole thread, and was able to confirm my understanding :

The 'skid' is a titanium 'ring jacket' that sits around a measurement hole, and is mounted to the plank around the hole, via some sort of screw mechanism, such that the screw heads are NOT flush with the skid itself, but the skid itself is flush with the woodend underside of the plank. Like this there are many FIA defined 'measurement holes' on the plank and the teams are free to design and fit their own version of skid around these holes. The idea is that the titanium will preserve the shape of the hole, and won't get chipped-away easily like wood and hence the wear on this titanium will be an indicator of how "low" the reference plane attempted to sink near to the tarmac (thereby offering an aerodynamic advantage). Essentially the skid block is like a bump stopper at one end of the spring in regular cars, and in F1, there is a way to 'measure' how severely the bump stop has gotten hit over a race. Hope this is a simple enough layman level understanding.

However, there is one thing which I am not able to 'imagine correctly' - please help me understand. There are posts talking about 'cleverly mounting' the skid block such that the orientation of the wear can be manipulated. How ? I am assuming that the measuring device is something that has a perfectly horizontal surface and is abutted flush with the measuring hole and some laser or something uses a reflective mechanism to determine the 'height/depth' of the hole. Can someone help me understand what this 'clever mounting' can be ?

[venkyhere]

Its strange that they had the points headroom to soften the risk profile just a little, for Lando's car at LV, but went headlong into pushing hard, it seems on every aspect.

A little of a roll-in to this championship position would have allowed then comfort in decision for the last two.

well, if The Race is to be believed, in Vegas McLaren lowered the rear of the car to prevent the car from graining at the front, which they suffered from on Friday. So if true, it's not quite sure what effect running a bit higher would have had. Potentially they would have been significantly worse with a legal car.

This is confusing. How can 'lowering the rear' (which shifts the center-of-mass / center-of-pressure rearwards) result in reducing front graining ? As per my understanding, graining is when the core/bulk of the tyre isn't hot enough to match the surface/tread of the tyre which has been heating up due to sliding (low grip tarmac). Now what will help prevent this ? more "load" on the front tyres or less "load" ? I think 'more load' is the answer. Which is why I am confused by that claim.

[Zynerji]

Its strange that they had the points headroom to soften the risk profile just a little, for Lando's car at LV, but went headlong into pushing hard, it seems on every aspect.

A little of a roll-in to this championship position would have allowed then comfort in decision for the last two.

well, if The Race is to be believed, in Vegas McLaren lowered the rear of the car to prevent the car from graining at the front, which they suffered from on Friday. So if true, it's not quite sure what effect running a bit higher would have had. Potentially they would have been significantly worse with a legal car.

This is confusing. How can 'lowering the rear' (which shifts the center-of-mass / center-of-pressure rearwards) result in reducing front graining ? As per my understanding, graining is when the core/bulk of the tyre isn't hot enough to match the surface/tread of the tyre which has been heating up due to sliding (low grip tarmac). Now what will help prevent this ? more "load" on the front tyres or less "load" ? I think 'more load' is the answer. Which is why I am confused by that claim.

I would expect that by adding more rear load, the front wing can be cranked up and be balanced, increasing load on both axles.

[venkyhere]

well, if The Race is to be believed, in Vegas McLaren lowered the rear of the car to prevent the car from graining at the front, which they suffered from on Friday. So if true, it's not quite sure what effect running a bit higher would have had. Potentially they would have been significantly worse with a legal car.

This is confusing. How can 'lowering the rear' (which shifts the center-of-mass / center-of-pressure rearwards) result in reducing front graining ? As per my understanding, graining is when the core/bulk of the tyre isn't hot enough to match the surface/tread of the tyre which has been heating up due to sliding (low grip tarmac). Now what will help prevent this ? more "load" on the front tyres or less "load" ? I think 'more load' is the answer. Which is why I am confused by that claim.

I would expect that by adding more rear load, the front wing can be cranked up and be balanced, increasing load on both axles.

They didn't 'add more rear load' (which would be via more beam wing / more rear wing) , they 'lowered the rear' , ie, static ride height. The rear wing was paper-thin, as we saw.

[search]

Its strange that they had the points headroom to soften the risk profile just a little, for Lando's car at LV, but went headlong into pushing hard, it seems on every aspect.

A little of a roll-in to this championship position would have allowed then comfort in decision for the last two.

well, if The Race is to be believed, in Vegas McLaren lowered the rear of the car to prevent the car from graining at the front, which they suffered from on Friday. So if true, it's not quite sure what effect running a bit higher would have had. Potentially they would have been significantly worse with a legal car.

This is confusing. How can 'lowering the rear' (which shifts the center-of-mass / center-of-pressure rearwards) result in reducing front graining ? As per my understanding, graining is when the core/bulk of the tyre isn't hot enough to match the surface/tread of the tyre which has been heating up due to sliding (low grip tarmac). Now what will help prevent this ? more "load" on the front tyres or less "load" ? I think 'more load' is the answer. Which is why I am confused by that claim.

McLaren now says they didn't lower the car at all, but "added a safety margin for qualifying and the race, compared to practice, in terms of clearance to the ground".

But obviously, no clue how much of whatever they publicly say is the truth.

https://www.the-race.com/formula-1/mcla ... -findings/

[basti313]

They didn't 'add more rear load' (which would be via more beam wing / more rear wing) , they 'lowered the rear' , ie, static ride height. The rear wing was paper-thin, as we saw.

I think you need to look into the overall concept on drag vs downforce and how the floor generates downforce. That post does not make sense.

And they did not add rear load. The McLaren is the best car on generating forward downforce by the floor. So anything they gain on ride height works also on the front tires, directly.

But obviously, no clue how much of whatever they publicly say is the truth.

Nothing. As mentioned in the McLaren post and this is rather where this belongs: I am deeply astonished on how clean the McL communications are. Just perfect.
They are talking a lot, but there is nothing that tells anything on the concept of the car, on the source of the issue, anything that can come back to them (compare this to Mekkies and the engine swap).
Forget about what they say on the topic.

https://www.the-race.com/formula-1/mcla ... -findings/

Come on...all this story is as said above...just talking and nothing. I would call most things BS:
- If a crucial sensor fails on the Nr2 car, you go by the values on the Nr1 car. Complete nonsense talking about a failed sensor if both are driving the same race and obviously the same setup.
- Porpoising is a factor of ride height. Every car has it and every car needs to dial it out by going higher. They were too low, nothing else. They tried to play it with LICO and failed on it.

[venkyhere]

well, if The Race is to be believed, in Vegas McLaren lowered the rear of the car to prevent the car from graining at the front, which they suffered from on Friday. So if true, it's not quite sure what effect running a bit higher would have had. Potentially they would have been significantly worse with a legal car.

They didn't 'add more rear load' (which would be via more beam wing / more rear wing) , they 'lowered the rear' , ie, static ride height. The rear wing was paper-thin, as we saw.

I think you need to look into the overall concept on drag vs downforce and how the floor generates downforce. That post does not make sense.

And they did not add rear load. The McLaren is the best car on generating forward downforce by the floor. So anything they gain on ride height works also on the front tires, directly.

The race, myself and yourself are all saying the same thing.
My response of 'no load added' was to this :

I would expect that by adding more rear load, the front wing can be cranked up and be balanced, increasing load on both axles.

By lowering the car in the rear, yes more DF is added, but without benefitting the front much (maybe very little), what will happen for sure is that the DF balance will shift rearwards, making the front 'looser' in relation to rear, which will necessitate a more cranked up front wing (which was indeed the case as the pics show that McL39 ran a pretty big FW relative to others).

My point was that, to 'solve front graining' just lower the car evenly, why 'lower the rear alone' ? We know front suspensions tend to be setup stiffer than the rears anyway, so was this not a straight invitation for the rear plank / rear skids to wear excessively ? In other words, I am not seeing how the explanation quoted as given by 'the-race' , where they say that front graining was the reason for lowering the rear - wouldn't 'lowering overall' (instead of just the front) be better at reducing graining, rather than lowering only the rear ? There weren't any long radius high speed corners in LasVegas either, were a more rearwards center-of-pressure would be preferable. So I don't understand the 'solution' for solving the 'problem' (front graining).

[basti313]

By lowering the car in the rear, yes more DF is added, but without benefitting the front much (maybe very little)

I do not think this is true in general. The floor works better when lower and this is a feature most likely for the full floor in a ground effect car. There may be a shift as you say, but if this shift is backwards or maybe even forwards, we can only assume.

making the front 'looser' in relation to rear,

Maybe. But I think this is irrelevant and can be controlled. The simple point is more downforce is more heat in the tire, is less graining.
So any downforce they gain at the front helps.

I did not see them down on straight line speed. So maybe what you say is true and they added front wing....it did not hurt, but helped with graining.
But in the end...does not matter, they were too low. This is the main point, all they showed this weekend, all about how the car was set up...it was too low rear and front to comply with the rules.

The big question of this thread is why it was sooo wrong.
I fear we will not see any other clues this season as the remaining tracks are just flat as flat can be.

[Zynerji]

By lowering the car in the rear, yes more DF is added, but without benefitting the front much (maybe very little)

I do not think this is true in general. The floor works better when lower and this is a feature most likely for the full floor in a ground effect car. There may be a shift as you say, but if this shift is backwards or maybe even forwards, we can only assume.

making the front 'looser' in relation to rear,

Maybe. But I think this is irrelevant and can be controlled. The simple point is more downforce is more heat in the tire, is less graining.
So any downforce they gain at the front helps.

I did not see them down on straight line speed. So maybe what you say is true and they added front wing....it did not hurt, but helped with graining.
But in the end...does not matter, they were too low. This is the main point, all they showed this weekend, all about how the car was set up...it was too low rear and front to comply with the rules.

The big question of this thread is why it was sooo wrong.
I fear we will not see any other clues this season as the remaining tracks are just flat as flat can be.

There can be speed dependent modes that are simply favorable to a specific circuit due to the varying nature of corners. I would assume that they sling the sprung weight and set the wings and ride-height based upon the optimum df/dr for a given set of corners, IE: per track.

[venkyhere]

I read through the whole thread, and was able to confirm my understanding :

The 'skid' is a titanium 'ring jacket' that sits around a measurement hole, and is mounted to the plank around the hole, via some sort of screw mechanism, such that the screw heads are NOT flush with the skid itself, but the skid itself is flush with the woodend underside of the plank. Like this there are many FIA defined 'measurement holes' on the plank and the teams are free to design and fit their own version of skid around these holes. The idea is that the titanium will preserve the shape of the hole, and won't get chipped-away easily like wood and hence the wear on this titanium will be an indicator of how "low" the reference plane attempted to sink near to the tarmac (thereby offering an aerodynamic advantage). Essentially the skid block is like a bump stopper at one end of the spring in regular cars, and in F1, there is a way to 'measure' how severely the bump stop has gotten hit over a race. Hope this is a simple enough layman level understanding.

However, there is one thing which I am not able to 'imagine correctly' - please help me understand. There are posts talking about 'cleverly mounting' the skid block such that the orientation of the wear can be manipulated. How ? I am assuming that the measuring device is something that has a perfectly horizontal surface and is abutted flush with the measuring hole and some laser or something uses a reflective mechanism to determine the 'height/depth' of the hole. Can someone help me understand what this 'clever mounting' can be ?

Can someone kindly help me understand the above Q (bold) ?

This is the reference I have (probably this pic helps out others as well, who are just visiting the thread and not posting) :

[Farnborough]

This is the stated measurement device quoted by FIA report, a "Mitutoyo Micrometer" and purchased in May 2025 they note.

https://www.amazon.co.uk/Mitutoyo-103-1 ... B0CHWC9ZLJ

To measure, the small end with little anvil is passed through the access hole to touch the "top" side of skid, the dial is then screwed in until the moving anvil touches the "bottom" plane (like a small clamp would) then , the measurement between those two anvil is noted from the markings around the barrel of the "handle" to give precise measurement.

This size 0~25mm range can be accurately checked by closing it to zero point, to then check the scale is also reading that as zero.

Its very simple and absolutely routine in engineering measurement. There's infinitesimally small chance of arguing any way out of the reading and mechanical process.

[basti313]

Funny thing, never really followed up: The first reports on the trick said we should have seen a drop in performance in Brazil from Sprint to Race as the affected teams had to remove their heaters.

Can you see this drop? I will give it a try:
McLaren: Less dominant in the race than in the sprint and Pia was worse. Not super conclusive.
Merc: No change.
RedBull: Dropped like flies.
Ferrari: Improved.
RB: Improved.
Aston: Dropped like flies.

Looking at this....Aston and RedBull are linked by personal moving. McLaren had its mojos, maybe this was one of them.
I never understood the fuss about the floors RedBull had since Monza. But one idea is now shaping in my mind: What if...the big thing about the Monza floor upgrade was not the minor shape change, but the heated skids? With the heated skids they could just go down. Might also explain their super strong last stint in Mexico, they knew they were safe and went full pace while others did Lico galore for skids.