F125 kerb usage – when to use curbs and when to avoid them

Learn about F125 kerb usage – when to use curbs and when to avoid them

Updated October 18, 2025

If kerbs keep snapping your car around, invalidating laps, or giving mystery time losses, you’re not alone. In F1 25 the car is stiff, low, and very sensitive to bumps. Small changes in steering angle, throttle, and ride height decide whether a kerb helps you rotate or throws you off. This guide will make F125 kerb usage – when to use curbs and when to avoid them feel consistent, predictable, and fast.

Quick Answer

Kerbs are tools, not targets. Use flat or low serrated kerbs while you’re mostly straight and light on inputs to straighten lines and carry speed. Avoid tall serrated or “sausage” kerbs when you’re braking, at high steering angles, or on throttle. If it’s bumpy, approach shallower, touch with inner wheels only, and soften your setup a click or two if needed.

Why F125 kerb usage – when to use curbs and when to avoid them Feels So Hard at First

The F1 25 car runs very low to the ground with stiff suspension. Kerbs can unload a tire, bottom the floor, or spike traction control, causing snaps.
Track limits are strict: using a kerb can be legal, but touching the painted runoff or a sausage can invalidate instantly.
The “right” approach changes by kerb type and what the car is doing (braking, coasting, or accelerating).

By the end of this guide, you’ll know exactly which kerbs to attack, which to skim, which to avoid, and how to set up the car and your inputs to make them work.

What F125 kerb usage – when to use curbs and when to avoid them Actually Means in F1 25

Think of kerbs by type and what they do to the car:

Flat painted kerbs (low profile): Usually safe. Help you straighten the line. Minimal bump.
Low serrated kerbs (gentle rumble): Often usable if you’re light on steering/brake/throttle. Adds small vibration that can unsettle if you’re at the limit.
High serrated kerbs (taller teeth): Risky. Can bounce the car, bottom the floor, and unload an inside tire.
Sausage/banana kerbs (raised yellow/orange bumps): Avoid. They can launch the car, damage your lap, or spin you.
Exit kerbs with green paint beyond: Kerb is usually legal; green paint is not. Use kerb, avoid green.

What kerbs change in-car:

Wheel load balance: Bumps take load off one tire → loss of grip or “inside-wheel spin.”
Floor/ride height: Bottoming kills downforce and stability.
Steering/throttle state: The more you’re steering or on power, the harsher the kerb effect.

Before You Start (Prerequisites)

Hardware: Controller or wheel is fine. Kerb principles are the same; inputs need to be smooth on both.
Game mode: Use Time Trial to learn kerbs (consistent fuel/tyres). Then test in Grand Prix or Career with race fuel and tire wear.
Menus you’ll use:
- Main Menu > Solo > Time Trial
- Garage > Car Setup (Aerodynamics, Transmission, Suspension, Brakes, Tyres)
- Settings > Assists (Traction Control, ABS)
- Optional: OSD/On-Screen toggles for track limits and delta

Step-by-Step: How to Fix / Improve F125 kerb usage – when to use curbs and when to avoid them

Learn the corner state before the kerb

Identify: Are you braking, coasting, or accelerating at the kerb?
Rule of thumb:
- Braking + kerb = avoid or minimize
- Coasting + kerb = usable if low/flat
- Accelerating + kerb = skim only, straighten the wheel

You should now be labeling each kerb by “brake/neutral/throttle.” That dictates how aggressive you can be.

Map the kerbs per track in Time Trial

Load a track you know (e.g., Austria or Spain).
Do 3 reconnaissance laps at 9/10ths pace:
- Mark flat/low serrated kerbs as “usable.”
- Mark tall serrated or sausages as “avoid.”
- Note which exits are safe to ride (kerb only) vs. where the green is close.
Use Instant Replay to watch tire placement in slow motion.

You should now have a mental list of green-light, yellow, and red kerbs for this circuit.

Use apex kerbs with the inside wheels only

Clip the inside kerb with just the inner tires; keep the chassis off the high part.
Approach at a shallow angle; avoid hitting kerb edges at 90°.
Keep inputs light across the kerb:
- Brake release should be smooth and complete just before the big bump.
- Minimal steering angle while on top of the kerb.
- Delay throttle until the car is settled, then squeeze.

You should feel less vibration and fewer snaps while still gaining rotation.

Manage exit kerbs under power

Favor the smoother inside half of the exit kerb.
Keep steering angle small as you reach the kerb, then unwind the wheel.
If traction breaks over the kerb:
- Short-shift one gear up.
- Lower Transmission > On-Throttle Differential by 2–4% (e.g., from 60 to 56–58) for more forgiveness.
- Add 1 click rear wing if exits are generally loose.

You should see more consistent traction lights and fewer delta losses on exit.

Avoid braking on serrated or tall kerbs

If your ideal line forces braking over a rough apex, move braking 2–5 meters earlier and finish 5–10% earlier.
Alternatively, steer less and trail-brake more gently so the kerb hit happens at lower load.

You should no longer feel the “ABS stutter” or front skipping when touching that kerb.

Tame bouncy chicanes

For quick left-rights:
- Straighten the car between kerbs; tiny lift if needed.
- Use just the flat/first third of each kerb.
- Don’t straddle both sausage kerbs; pick the flatter side, keep the car stable, and prioritize exit.
If the car pogos:
- Suspension > Front Suspension 1–2 clicks softer.
- Suspension > Front Anti-Roll Bar 1 click softer for compliance.
- Suspension > Ride Height (Front/Rear) +1 click each if bottoming.

Success looks like the car taking a clean “hop” without a second bounce or snap.

Setup refinements for kerb compliance (small, safe changes)

Transmission
- On-Throttle Diff: Slightly lower (easier traction over exit kerbs).
- Off-Throttle Diff: Slightly higher if entry kerbs make the rear nervous; slightly lower if you need more rotation and it’s stable.
Suspension
- Front/Rear Springs: 1–2 clicks softer if kerbs feel harsh; keep balance similar.
- Anti-Roll Bars: Soften the end that’s losing grip over kerbs (front push = soften front ARB a click; rear snaps = soften rear a click).
- Ride Height: +1 click if you’re bottoming; too much adds drag/understeer.
Tyres
- Lower pressures by 0.1–0.2 bar if you’re skittering across kerbs; watch temps.

Check that the car no longer bottoms (audible scrape) and that traction over kerbs is smoother.

Controller-specific smoothing

In Settings > Controls:
- Add a little steering deadzone (1–2) and saturation (2–5) to calm kerb kicks.
- Reduce vibration strength slightly if it masks feel.
Maintain tiny throttle overlaps across kerbs rather than 0%→100% spikes.

You should notice fewer mid-corner spikes and better exit control on rumble.

Validate in race conditions

Test the same kerbs in a Grand Prix session with race fuel.
Adjust braking points slightly earlier, and be extra conservative with exit kerbs on worn tyres.

You should still hit the same kerbs, just with calmer inputs and slightly earlier commitment.

Common Mistakes and Myths About F125 kerb usage – when to use curbs and when to avoid them

“All apex kerbs are free time.” Myth. High serrated or sausage apex kerbs are time-loss or spin traps, especially under braking.
“If pros jump kerbs, I should too.” Context matters: setups, assists, and precision. Start with inner-wheel clips, not full mounts.
“Higher diff equals more traction.” Not always. Too high on-throttle diff can snap the rear when one wheel unloads on a kerb.
“Softer is always better over kerbs.” Over-softening reduces responsiveness and can hurt change-of-direction. Make small changes.
“Kerbs are the same in wet.” They’re not. Painted surfaces get greasy; avoid aggressive kerb use in rain.

Troubleshooting and “What If It Still Feels Wrong?”

Car snaps when I touch an exit kerb on throttle
- Likely cause: Inside rear unload + too much throttle or high on-throttle diff.
- Fix: Short-shift; lower on-throttle diff 2–4%; add 1 click rear wing; unwind steering earlier.
Front washes wide when braking across an apex kerb
- Likely cause: Braking on a bumpy surface; front is skipping.
- Fix: Finish braking earlier; smooth trail-brake; avoid the tallest part of the kerb; soften front ARB 1 click.
Rear hops over chicanes and doesn’t settle
- Likely cause: Car too stiff/low or steering too much across kerb.
- Fix: Soften rear springs or ARB 1 click; raise ride height +1; hit kerb shallower; reduce steering angle through the bump.
Constant invalidations at exits
- Likely cause: Touching the green beyond the kerb.
- Fix: Aim to place outer tires on the kerb, not beyond; use the delta line as a visual; lift 2–3% throttle to tuck the car back.
No lap-time gain even when using safe kerbs
- Likely cause: Inputs too cautious; not straightening lines.
- Fix: Enter 2–3 km/h faster where kerb is flat; reduce steering angle over the kerb; commit to throttle 0.1s earlier once settled.

Note: Don’t max out any one setup slider to “solve” a kerb. It often creates new problems (e.g., too-soft suspension hurting change-of-direction).

Pro Tips Once You’re Comfortable

Pre-position the car: Sacrifice 10 cm of entry to land the car flat on the kerb you plan to use.
Time your brake release so the biggest kerb hit happens at near-neutral brake and modest steering angle.
In quick chicanes, think “tap–tap”: brief, shallow clips of each kerb rather than fully mounting either.
In wet or on cold tyres, halve your usual kerb usage until temperatures rise.

How to Know It’s Working (Definition of Done)

Run 5-lap stints in Time Trial and check:

Invalidations drop to near zero.
Your delta improves especially through chicanes and long exits.
Steering traces look smoother (fewer sharp corrections) across kerbs.
You feel one controlled “bump” rather than a bounce–snap sequence.

If you can repeat the same kerb usage three laps in a row with stable exits, you’ve nailed it.

Now that your F125 kerb usage – when to use curbs and when to avoid them is dialed in, the next big gain usually comes from improving your braking technique. Check out our guide on F125 braking technique.
Fine-tune stability with our F125 differential setup guide.
Struggling in quick direction changes? Read our F125 chicane technique guide.

What F125 kerb usage – when to use curbs and when to avoid them Means in F1 25

As a final recap:

Use flat/low kerbs when you’re straight or nearly so, with gentle inputs.
Avoid tall serrated/sausage kerbs, especially while braking or on power.
Approach at shallow angles, clip with inner wheels, and keep the car settled with smooth brake release and measured throttle.
Make small setup tweaks (diff, ARBs, ride height) only if technique isn’t enough.