Windows Errors? Fix Them Before They Spread
Repair common Windows errors and clear accumulated junk for a smoother, more stable PC - no reinstall needed.Free scan · no reinstallOutdated Drivers Are Slowing You Down
One free scan finds every outdated or missing driver and matches the right update for your exact hardware.Free scan · exact hardware matchLewis Hamilton’s Ferrari finished sixth on the road at the 2025 Chinese Grand Prix, but post-race checks found its plank assembly measured 8.6 mm on the left, 8.6 mm at the centreline and 8.5 mm on the right. The rule in force at that race required at least 9 mm after wear, so Ferrari was disqualified despite the breach being only a few tenths of a millimetre.
An F1 plank assembly is the regulated underfloor structure made up of the central plank, skid inserts and mountings. It controls how aggressively teams can run the car close to the track. Officials do not measure live ride height throughout the race; they inspect the assembly after running at prescribed locations. As of 10 August 2026, the current rule is an 8 mm minimum measured around three 34 mm holes—not the 9 mm, four-hole system used in 2025.
Plank, skid and skid block: what is the difference?
In precise FIA terminology, the plank assembly is the complete regulated structure: the central plank, its skid inserts and the mountings that hold it to the car.
- Plank: the long, centrally mounted plate beneath the floor.
- Skids: flush-mounted wear inserts positioned around designated measurement holes.
- Plank assembly: the plank, skids and mountings considered together.
“Skid block” is widely used by broadcasters and newspapers to describe the whole part, but it is technically imprecise. The skids are only local inserts; the large underfloor plate is the plank.
#1 Best Overall
The assembly sits below the aerodynamic floor. Under the current 2026 regulations, its upper surface is defined at the reference plane, Z=0. A simplified cross-section looks like this:
Car floor and aerodynamic tunnels
Mountings
Plank + flush skid inserts
Track surface
It is not an external aerodynamic bodywork component. Its importance comes from controlling how close the aerodynamic floor may run to the track and from the physical evidence left behind after a race.
Why did F1 introduce the plank?
The plank was introduced in 1994 as part of the FIA’s safety response following the deaths of Roland Ratzenberger and Ayrton Senna at Imola. The aim was to discourage teams from running the centre of the car dangerously close to the ground, where underfloor airflow could produce a sudden loss of aerodynamic performance. Formula 1’s technical history describes the plank’s introduction and purpose in more detail in its technical history of the plank.
The plank is therefore not a device that directly measures ride height during a race. It is a physical limit and a post-race compliance check. Excessive wear suggests that the car has spent too much time contacting the track or running close enough to it for the floor to abrade.
Do these 3 things before closing this tab:
1Repair Windows errors before they cause bigger problems2Fix the driver behind crashes, sound loss and screen glitches3Clear out junk files and repair common Windows errorsWhat does the plank do on a modern F1 car?
Modern ground-effect cars generate a large proportion of their downforce from airflow passing beneath the floor. As speed rises, aerodynamic load compresses the suspension and pulls the floor closer to the circuit. That can improve performance—up to the point where the floor begins striking the track or its airflow becomes unstable.
The plank assembly has three connected roles:
- It limits the advantage of an ultra-low setup. Teams cannot simply lower the car indefinitely to gain underfloor downforce.
- It offers some physical protection. The plank and skids take contact from bumps, kerbs and the track surface before more delicate floor components do.
- It gives the FIA a practical compliance proxy. Officials can inspect the final wear at defined locations rather than trying to reconstruct the car’s live ride height for every lap.
The 2022 ground-effect regulations made low-floor operation especially important, which also made the relationship between ride height, bottoming, porpoising and plank wear more significant. Formula 1’s explanation of the floor regulations and technical directive provides useful background.
How does an F1 car wear its plank?
Wear is caused by repeated contact and abrasion. A car may touch the circuit when:
- downforce compresses the suspension at high speed;
- the ride height is set very low;
- the circuit is bumpy;
- the car crosses kerbs;
- heavy braking and cornering generate large vertical and lateral loads;
- porpoising repeatedly drives the floor toward the track; or
- damage or a displaced floor component changes the way the car contacts the ground.
The setup problem is a constant trade-off. A lower car can produce more underfloor downforce, but it has less wear margin. Raising the car generally reduces the risk of failing scrutineering, while potentially costing aerodynamic performance. Teams also have to account for fuel load, tyre degradation, wind, temperature, bumps, kerbs, suspension stiffness and porpoising.
There is no universal lap-time penalty for raising the car. The cost depends on the circuit and the design of the individual car. A setup that is legal and fast at a smooth track may be risky at a bumpy venue or during a Sprint weekend with limited practice.
2025 versus the current 2026 rules
The numbers often quoted in coverage of Lewis Hamilton’s 2025 Chinese Grand Prix disqualification are not the current numbers. The rule in force at that event required a minimum post-use thickness of 9 mm. The current FIA 2026 rulebook uses an 8 mm minimum.
Rank #2
As of 10 August 2026, the FIA’s published technical regulations list Issue 20 as the current 2026 technical rulebook. Regulations can be amended by issue, so the applicable version should always be checked against the event date on the FIA Formula 1 technical regulations page.
| Detail | 2025 rule relevant to Hamilton’s China DSQ | Current 2026 rule |
|---|---|---|
| Regulation article | Article 3.5.9 | Article C3.6 |
| New thickness | 10 mm ± 0.2 mm | 10 mm ± 0.2 mm |
| Minimum after wear | 9 mm | 8 mm |
| Measurement holes | Four | Three |
| Hole diameter | 50 mm | 34 mm |
| Measurement area | Periphery of designated holes | Entire periphery of each designated hole |
| What may be measured | Plank or skid material present at the hole | Skid is removed and physically measured |
| Specified instrument | Not specified in the main 2025 article | Micrometer with a 6.35 mm-diameter anvil |
| Metallic skids | Titanium permitted under defined restrictions | Metal mandatory around the forward hole; optional at the middle and rear holes |
The full wording is in the 2025 FIA Technical Regulations, Issue 3 and the 2026 FIA Technical Regulations, Issue 20. The FIA has not publicly explained in the supplied sources the precise rationale for every 2026 change, including the move from four 50 mm holes and a 9 mm limit to three 34 mm holes and an 8 mm limit.
The Tool Desk
Outbyte PC Repair FREERepair Windows errors before they cause bigger problemsFix Now →Outbyte Driver Updater FREEScan for outdated or missing drivers - takes under a minuteDriver Scan →How does the FIA measure plank wear?
The 2025 procedure
Under the 2025 regulations, the plank assembly started at 10 mm ± 0.2 mm. After the event, it had to remain at least 9 mm thick at the specified measurement locations.
The assembly had four precisely located holes, each 50 mm in diameter. FIA officials checked the material at the periphery of those designated holes. Depending on the location and construction, that material could be part of the plank or a skid insert.
The rule was not an average-thickness test across the complete floor. A local measurement below the applicable minimum could make the car non-compliant even if other areas looked healthy.
The 2026 procedure
Article C3.6 of the current 2026 regulations defines three 34 mm-diameter holes at FIA-prescribed longitudinal positions. The new assembly thickness remains 10 mm ± 0.2 mm, but the post-use minimum is 8 mm.
The current process is more explicit:
- The car is selected for the relevant post-race inspection.
- The skid is removed from the car for physical measurement.
- A micrometer with a 6.35 mm-diameter anvil is used.
- The entire periphery of every designated hole must remain within the permitted tolerance.
One failed measurement is enough to create a technical non-compliance issue. The result is not calculated from an average thickness across the plank.
It is useful shorthand to say that the FIA “measures ride height”, but that is not technically exact. The FIA measures the final physical condition of the plank assembly at prescribed points. The wear is used as evidence of how aggressively the car was operating near the ground.
Are F1 planks made of wood?
Not necessarily. Historic F1 cars used wood-based composite material such as Jabroc, which is why “wooden plank” remains common shorthand. Modern F1 moved toward a glass composite known as Permaglass, which is more stable and abrasion-resistant, according to Pat Symonds’ technical history published by Autosport.
The FIA does not simply mandate a commercial product name. It regulates the material’s density, geometry and construction. Under the 2025 rules, the plank material was constrained by density limits of approximately 1.3–1.45 specific gravity, with additional requirements for pocketed construction. The plank could contain no more than three pieces, including a minimum-length requirement for the forward piece.
Rank #3
The broad density limits remain in the 2026 rules. The detailed construction and mounting requirements are set out in Article C3.6 of the FIA rulebook.
What are the skids made from?
Skids are wear inserts around the measurement holes. They can be made from composite plank material or, where the regulations permit or require it, metal.
Under the current 2026 rules:
- a metallic skid is mandatory around the forward measurement hole;
- metallic skids are optional around the middle and rear holes;
- where metal is not used at those optional positions, plank material may replace or integrate the skid; and
- the permitted metallic materials are Ti6Al4V titanium or 17-4PH stainless steel, as specified by the FIA’s documentation for the competition.
It is therefore inaccurate to say that every current F1 skid is titanium. The exact skid arrangement depends on the location and the applicable regulations.
Why do F1 cars produce sparks?
The sparks seen beneath F1 cars normally come from exposed metallic skids touching the asphalt. They do not come from the composite plank itself.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
Sparks are not a legality test. A car can be legal and produce sparks when a permitted metal skid contacts the track. Conversely, a car can exceed the wear limit without producing a dramatic shower of sparks.
How can a tiny measurement erase a race result?
The plank limit is a technical eligibility rule, not a points-based performance adjustment. If the post-race inspection establishes that the car is outside the applicable technical specification, the stewards may exclude it under the regulations even when the breach is accidental and even when the measured difference is only a few tenths of a millimetre.
That does not mean the measurement proves intentional cheating, a specific illegal device or a precisely quantifiable performance gain. It proves that the component did not comply with the stated technical limit at the inspected location.
Recent F1 plank disqualifications explained
Lewis Hamilton: 2025 Chinese Grand Prix
Hamilton’s Ferrari finished sixth on the road at the 2025 Chinese Grand Prix, but the car was disqualified after the plank assembly was measured below the then-current 9 mm minimum:
Recommended Free Tools
- 8.6 mm on the left-hand side;
- 8.6 mm at the centreline; and
- 8.5 mm on the right-hand side.
Ferrari confirmed the measurements and acknowledged a genuine team error. The stewards applied the standard disqualification penalty in the documented case. The important detail is the date: Hamilton was judged under the 2025 9 mm rule, not the current 2026 8 mm rule. The official FIA decision records the measurements and infringement.
Lewis Hamilton and Charles Leclerc: 2023 United States Grand Prix
Hamilton and Charles Leclerc were both disqualified at Austin after post-race inspections found excessive plank wear. The circuit was bumpy, and the Sprint-weekend format limited the time available to refine the setup. The incident showed how a setup that is aggressively low can become a compliance risk over race distance.
Formula 1’s Austin explainer describes the case and the technical issue.
Nico Hülkenberg: 2025 Bahrain Grand Prix
Hülkenberg’s Sauber was measured at 8.4 mm on the left, 8.5 mm at the centreline and 8.4 mm on the right. All three measurements were below the 2025 9 mm minimum, and the car was disqualified. The team acknowledged a genuine error. The official FIA decision documents the measurements.
Lando Norris and Oscar Piastri: 2025 Las Vegas Grand Prix
McLaren’s two cars were excluded at Las Vegas for plank-assembly non-compliance. In the FIA decision concerning Piastri, the rear skid measurements were 8.96 mm, 8.74 mm and 8.90 mm—each below the 2025 9 mm limit.
McLaren argued that unexpected porpoising, limited practice and possible accidental damage were mitigating circumstances. The stewards considered those arguments but concluded that the regulations and precedent did not provide an alternative penalty for the technical breach. The official Piastri decision is the relevant source for those measurements and the stewards’ reasoning.
This is the clearest recent example of the distinction between cause and compliance. Porpoising or accidental damage may explain why a component wore too far, but they do not automatically restore legality.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Why does the FIA not check every part of every car?
Post-race legality checks take place under tight time constraints. The FIA combines standard checks with random selections and deeper targeted inspections. Checking every possible parameter on every component of every car at every event would not be practical within the post-race timetable.
Free tools Windows power users keep installed
One-click scans. No signup required.
The inspection process is explained in the FIA’s post-race legality overview. A car not selected for a particular plank inspection should not be interpreted as having received a blanket technical certification for every possible component.
Common misconceptions
“The plank is just a wooden board.”
That is an outdated simplification. Historic planks used wood-based composite material, but modern assemblies commonly use regulated glass/resin composite construction, with local metallic or composite skids depending on the rules.
“Skid blocks and planks are exactly the same thing.”
No. A skid is an insert; the plank is the main central plate; the plank assembly includes both, plus mountings. Media coverage often uses “skid block” as shorthand for the assembly.
“The FIA measures the car’s ride height during the race.”
No. The FIA performs a post-use physical measurement at defined locations. The result acts as a proxy for how aggressively the car ran near the ground.
Quick wins for a faster PC:
Repair Windows errors before they cause bigger problemsFix Now →Scan for outdated or missing drivers - takes under a minuteDriver Scan →Clear out junk files and repair common Windows errorsFree Scan →Best Value
“There are always four 50 mm holes.”
That describes the relevant 2025 rules. The current 2026 regulations define three 34 mm holes.
“The minimum is always 9 mm.”
9 mm was the applicable minimum in 2025, including at the Chinese, Bahrain and Las Vegas races discussed above. The current 2026 minimum is 8 mm under Article C3.6.
“Sparks prove the car is illegal.”
No. Sparks usually indicate metal contacting the asphalt, which can happen on a legal car. They neither prove nor disprove compliance.
“A small or accidental breach should receive a small penalty.”
Not necessarily. In the documented cases, teams described genuine errors, porpoising or possible damage, but the cars were still disqualified. The penalty for a future case depends on the applicable regulations and stewards’ decision.
Do these 3 things before closing this tab:
1Repair Windows errors before they cause bigger problems2Scan for outdated or missing drivers - takes under a minute3Clear out junk files and repair common Windows errorsWhy the plank matters so much
The plank assembly looks like a simple sacrificial plate, but it sits at the centre of F1’s aerodynamic compromise. Teams want the floor close to the ground because ground-effect tunnels can generate valuable downforce. The FIA wants a measurable limit that prevents teams from exploiting an ultra-low setup without consequence.
That makes the plank both a performance constraint and a piece of evidence. The car may be only a fraction of a millimetre below the limit at one inspected location, but the rule is based on whether the physical component complies—not on how much of an advantage the team intended to gain or whether the wear was visible from television pictures.
Frequently Asked Questions
Are F1 planks really made of wood?
Not necessarily. Historic F1 cars used wood-based composite material such as Jabroc, but modern planks commonly use regulated glass/resin composites. The FIA controls density, geometry and construction rather than requiring one commercial material.
Does the FIA measure ride height with the plank?
No. The FIA measures the used plank assembly at prescribed locations after running. That wear is a practical proxy for how aggressively the car operated near the ground; it is not a live ride-height measurement taken throughout the race.
The Tool Desk
Outbyte Driver Updater FREEScan for outdated or missing drivers - takes under a minuteDriver Scan →Outbyte PC Repair FREEClear out junk files and repair common Windows errorsFree Scan →What is the current F1 plank thickness limit?
Under the current 2026 rules, the plank assembly has three 34 mm measurement holes and must remain at least 8 mm thick after use. Under the relevant 2025 rules, there were four 50 mm holes and a 9 mm minimum.
Do sparks mean an F1 car is illegal?
No. A legal car may produce sparks when a permitted metallic skid touches the track, while a worn composite area may fail without dramatic sparks. Sparks alone do not establish legality.
Can accidental plank damage avoid disqualification?
Possible damage or porpoising may explain the wear, but it does not automatically remove the technical infringement. In the documented 2025 Las Vegas case, the stewards considered McLaren’s mitigating arguments but still disqualified the car.
Can one thin spot fail an F1 car?
One measurement below the applicable limit can be enough. The rule is not based on the average thickness of the entire plank, which is why a car can look intact and still fail a designated inspection point.
The Bottom Line
Bottom line: An F1 plank assembly is the regulated underfloor plate made up of the plank, skid inserts and mountings. It limits ultra-low running, protects the floor from contact and gives the FIA a practical wear-based compliance check. For races held under the 2025 rules, the post-use minimum was 9 mm; under the current 2026 regulations, it is 8 mm, measured at three prescribed 34 mm holes.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
