The skid block — also called the plank — is the FIA’s low-tech lie detector. It sits under the car, measures how cheeky teams ran their ride height, and sends offenders straight to the stewards. You want downforce? Sure. But grind this too thin and you’re going from podium to paperwork.
F1 introduced the plank in 1994 to stop cars from kissing the tarmac at warp speed. It forces a minimum ground clearance, reins in ground effect abuse, and keeps drivers from turning into lawn mowers through fast corners. Brilliantly simple. Brutally strict.
What Is It And Why Does It Exist?
The skid block is a flat rectangular piece mounted under the car, central and symmetrical. It’s not there to make the car faster. It’s there to make sure teams don’t set them up like hovercrafts. Minimum ride height by another name.
The closer the floor gets to the track, the more efficient the underbody aero becomes. That’s free lap time. But it’s also a fast track to unsafe bottoming and suspension overloads. Enter the plank — the sport’s wooden whistleblower.
FIA Spec: Numbers That Ruin Weekends
Regulations are tight enough to make engineers sweat. The block runs from 330 mm behind the front wheel centerline to the rear axle centerline. Width? 300 mm ±2 mm. Thickness? 10 mm ±0.2 mm when new. Homogeneous material. Uniform thickness. Fixed so air can’t sneak between it and the reference plane.
After racing, the allowed minimum is effectively 9 mm. That’s around 1 mm of legal wear. Go past that at the measuring holes and you’re done. No heroic speeches. Just disqualification. File this under: Yikes.
How It’s Measured
Scrutineers check thickness through specific holes drilled in the plank — four at 50 mm diameter and two at 80 mm up front. They measure wear around the periphery. If any point’s below the mandated limit, the car is illegal. The titanium skid plates? They spark for show, but they don’t save you from the gauge.
- New thickness: 10.0 mm ±0.2
- Minimum legal after wear: 9.0 mm
- Checked at designated inspection holes
Materials: From Wood Shop To War Room
Early planks used Jabroc, a pressed beechwood laminate with consistent density and predictable wear. Later, F1 moved to permaglass (a fiberglass composite): light, tough, non-flammable, and reliably measurable. Other series still use Jabroc; F1 prefers space-age school rulers.
The plank doesn’t shape airflow. It’s a gauge, not a wing. Teams add titanium skids around it to take the hits and throw sparks. The sparks? Great for TV. Bad for your plank lifespan if you push your luck. Somewhere, a PR manager just had a minor stroke.
What It Actually Does On Track
It controls ride height indirectly. Run too low for too long, and the car grinds material away. Over kerbs? Bottoming in high-speed compressions? That’s your plank screaming for mercy. Teams balance this with setup: lower equals faster, but lower also equals risk.
On Sprint weekends, it’s worse. Parc fermé locks setups early. If you guessed wrong on bumps and wind, congratulations: you’re playing roulette with disqualification. The plot thickens like a team’s excuse list.
Historic Smackdowns: When The Plank Bites Back
1994 Belgium: Michael Schumacher finished first, then the plank said “nope.” Excessive wear. Disqualified. Yes, there was a spin over kerbs at Pouhon. No, it didn’t save him. The rulebook kept the trophy.
2023 United States GP: Lewis Hamilton and Charles Leclerc got nuked post-race for wear. Random checks, brutal results. They didn’t just lose positions — they became a cautionary tale. Lights out and away we… oh wait.
Recent High-Profile Examples
2025 Bahrain: Nico Hülkenberg was tossed for the rearmost skid block wearing under 9 mm — readings around 8.4–8.5 mm. Another masterclass in how NOT to run ride height at a bumpy desert track.
2025 China: Lewis Hamilton (Ferrari) fell foul with measurements at 8.5–8.6 mm on multiple points. Under the 9 mm floor. Under the rule. Over and out.
Why Cars Spark — And Why Teams Don’t Mind (Too Much)
The sparks come from titanium skid plates making contact. High fuel loads, heavy compression zones, and aggressive setups turn straights into fireworks displays. It looks spectacular. It also means drag, disturbance, and potential wear. Fun for fans, stressful for engineers.
Teams place those plates smartly to protect the plank. They’d rather scrape titanium than lose legality. But if the track beats you up — bumps, kerbs, aggressive camber — even the best armor won’t save a reckless setup. Did the strategists forget how to count laps? Again?
Setup, Strategy, And The Risk Game
Qualifying tempts everyone to slam the car down. It’s free downforce. Until it isn’t. The plank is the invisible wall that says “raise it or get erased.” Teams model wear rate per lap, per kerb, per sector. Ignore the data and the stewards will write the ending.
In races, wear management is constant. Track evolution, wind shifts, fuel burn-off — all change how hard the car hits the deck. The wind plays favorites too; apparently it’s a McLaren fan on some Saturdays.
Common Myths, Debunked
“It’s an aero device.” No. It’s a compliance tool. Any aero effect is incidental and minimized by design and placement. The job is measurement, not downforce.
“Sparks mean you’re illegal.” Also no. You can spark and still finish legal. But constant fireworks? That’s the universe whispering “raise your car, hero.”
How Teams Get Caught
Post-race, the FIA randomly selects cars and inspects components. Skid block wear is a favorite. If you’ve planked yourself into oblivion, the mic drop is swift: disqualification. Appeals rarely help when the calipers say you cheated the asphalt.
Prevention is boring but vital: ride height margins, damper tuning, kerb usage guidelines, and driver briefings. Ignore them and you’ll be collecting disappointments like they’re Pokemon cards.
Weather And Track As Co-Conspirators
The heat pumps up track temps, softens tires, and amplifies bottoming under load. The track temperature hit levels that would make Hell consider air conditioning.
Rain? The rain shows up like that friend who always causes drama at parties. Less grip, more bouncing, and unpredictable compressions. Recipes for plank gouges, served cold.
Future Of The Plank
Expect smarter materials, maybe embedded sensors to track real-time wear. Data straight to the pit wall. No more guessing games. Just cold numbers and quicker setup calls.
There’s also a push toward sustainable materials without sacrificing consistency. If it’s measurable, durable, and green enough for the FIA’s mood board, it’s on the table.
Signature Moves And The Plank
Watch for the classics: the ol’ Verstappen divebomb special — warranty void where prohibited. Great show, nasty on the plank if you clatter kerbs on exit. Risk and reward, tethered by ten millimeters.
When Hamilton’s hammer time wakes up, RIP lap times — but hit the ground too hard and the hammer smashes your Sunday. That’s the balance. That’s the sport.
Quick Reference: The Plank In One Glance
| Item | Key Detail |
|---|---|
| Purpose | Enforce minimum ride height, limit ground effect exploitation |
| New Thickness | 10.0 mm ±0.2 |
| Minimum After Wear | 9.0 mm at inspection holes |
| Width | 300 mm ±2 |
| Length Span | From 330 mm behind front axle to rear axle centerline |
| Material | Homogeneous composite (historically Jabroc, commonly fiberglass/permaglass) |
| Inspection | Measured via 6 holes; over-wear = disqualification |
| Sparks | Titanium skids hitting track — cool show, risky for wear |
The Bottom Line
The plank is small, savage, and non-negotiable. It keeps cars honest and engineers humble. Run too low and the competition? Reduced to expensive spectators, watching your result vanish from the timing screens.
You can flirt with the asphalt. You can’t marry it. The skid block makes sure of that — one millimeter at a time.