Posted by Liana Harrow
2 Comments
Ever feel like your car leans too much in corners? Like the whole thing is tipping over when you take a fast exit on a back road? That’s body roll - and it’s not just annoying, it’s dangerous. It kills grip, makes steering feel vague, and turns a fun drive into a nervous one. The fix isn’t always new tires or a full suspension overhaul. Sometimes, it’s just two simple upgrades: strut braces and sway bars.
Body roll happens when your car’s weight shifts during cornering. As you turn, centrifugal force pushes the car outward. The suspension on the outside of the turn compresses, while the inside lifts. That tilting motion - the lean - is body roll. It’s normal to a degree. Even a brand-new Honda Civic rolls a bit. But in performance cars, modified cars, or cars with worn suspension, it gets worse.
Here’s why it matters: when your car rolls, the tires lose contact with the road. The outside tires bear most of the load, while the inside ones lift slightly. That reduces overall grip. Your steering feels slow to respond. The car doesn’t track where you point it. And if you’re pushing hard, you might even get a sudden loss of traction.
Think of it like standing on a skateboard and leaning to one side. The board tilts, and you lose balance. Your car does the same thing - except at 60 mph.
Your car’s chassis is its skeleton. In modern cars, it’s made of stamped steel, welded together. But even the stiffest factory chassis flexes under stress - especially when you hit bumps mid-corner or slam the throttle out of a turn. That flex is invisible, but it’s there. And it’s bad for handling.
When the chassis twists, your suspension geometry changes. The alignment shifts slightly. The wheels don’t stay planted where they should be. That’s why a car can feel loose or unpredictable, even with perfect tires and shocks.
Chassis rigidity isn’t about being heavy. It’s about being stiff. A rigid chassis keeps everything aligned, so your suspension can do its job properly. That’s where strut braces and sway bars come in.
A strut brace is a metal bar that connects the top mounts of your front (or rear) struts. It’s usually bolted under the hood, just behind the engine. It looks like a simple steel tube or bar, sometimes with a carbon fiber finish.
What it does: stops the firewall and strut towers from flexing inward during hard cornering. Without a brace, the strut towers can bend slightly - just enough to change camber and toe angles. That’s why your steering feels vague at the limit. With a brace, the towers stay put. The suspension stays aligned. You get sharper turn-in and better feedback.
Real-world effect? In a Ford Focus ST or a Subaru WRX, a front strut brace makes the car feel more planted. You can feel the difference in the steering wheel - less wobble, more precision. It’s subtle, but once you drive with one, you notice how sloppy the car felt without it.
Not all strut braces are created equal. Cheap ones are just thin tubes with flimsy mounts. Good ones are made from 20mm steel, with reinforced mounting points. Brands like Cusco, Whiteline, and ST Suspension make reliable ones. For most street cars, a front brace is enough. Rear braces exist, but they’re mostly for track cars or those with rear strut setups.
A sway bar - also called an anti-roll bar - is a thick steel bar that connects the left and right wheels through links and bushings. It’s usually under the car, running across the axle.
Here’s how it works: when the car rolls, one side compresses and the other extends. The sway bar twists in response. That twisting force pushes back against the roll, keeping the car flatter. It doesn’t stop body roll completely - that’s not the goal - but it controls how much happens.
Factory sway bars are soft. They’re tuned for comfort, not grip. Upgrading to a thicker bar (say, from 20mm to 24mm) makes a huge difference. You’ll notice less lean in corners, faster response, and more even tire contact.
But there’s a catch: too stiff a bar can hurt ride quality. On rough roads, a too-stiff rear sway bar can make the car skip over bumps instead of absorbing them. That’s why adjustable sway bars are popular. You can dial in the stiffness based on whether you’re driving to work or heading to the track.
For a daily driver with occasional spirited driving, a 22mm front and 18mm rear bar combo (like from Eibach or Progress) strikes the right balance. For track use, go thicker - 25mm front, 20mm rear. Just remember: if you stiffen the front more than the rear, you’ll get understeer. Stiffen the rear more, and you’ll get oversteer. That’s tuning.
People mix them up. They both reduce body roll. But they work in completely different ways.
Strut braces reduce chassis flex. They keep the suspension mounting points rigid. Think of them as adding structural support to the car’s frame.
Sway bars control weight transfer. They physically link the wheels and push back against the roll force. Think of them as a mechanical lever that fights the car’s natural tendency to lean.
You can have one without the other. But together? They’re a game-changer.
Let’s say you install only a sway bar. Your car will corner flatter, but the steering might still feel vague because the strut towers are still flexing. Install only a strut brace? The steering gets sharper, but the car still leans - just with more precision.
Put both on? The car feels like it’s bolted to the road. Turn-in is immediate. Mid-corner corrections are effortless. You stop guessing how much grip you have.
Take a 2018 Volkswagen Golf GTI. Stock, it’s a fun hatchback. Add a Whiteline front strut brace and a 24mm rear sway bar. Now, it’s a different car.
On a twisty B-road near Bath, the difference is obvious. The car doesn’t lean. The front end bites instantly. You can carry more speed through corners without feeling like you’re about to slide. The steering feedback is clearer - you feel every bump, every change in grip. It’s not just faster. It’s more confidence-inspiring.
Another example: a 2020 Honda Civic Si. Factory sway bar is 20mm front, 18mm rear. Swap to a 22mm front and 20mm rear bar, and add a strut brace. The car stops feeling like it’s floating. It feels connected. You can drive it harder, with less thought.
These upgrades don’t add horsepower. They don’t make your car louder. But they make you feel like you’re driving a more serious machine.
You don’t need them if you’re just commuting or driving in the rain. But if you enjoy driving - if you like taking corners with purpose - then yes.
Strut braces are ideal for:
Sway bars are ideal for:
And if you’ve done any of these: upgraded shocks, added performance tires, lowered the car - then you’re already halfway there. Strut braces and sway bars are the final 20% that turn good handling into great handling.
Strut braces: Easy DIY. Most take under an hour. You need basic tools - socket set, torque wrench. Cost: £80-£200 depending on brand and material.
Sway bars: Slightly harder. You need to lift the car, remove stock bars, install new ones with new bushings. Takes 2-3 hours. Cost: £150-£400 for a quality set.
Both are bolt-on upgrades. No cutting, no welding. No permanent changes. You can remove them if you sell the car.
Pro tip: Always replace the bushings when installing a sway bar. Factory rubber bushings wear out and let the bar move slightly. Polyurethane or spherical bushings (like from Energy Suspension) give you zero deflection.
Don’t install a huge sway bar on a car with stock suspension. It’ll make the ride harsh and unpredictable. Don’t install a strut brace without checking if your car has the right mounting points. Some cars (like older BMWs) need custom brackets.
Don’t expect miracles. These aren’t magic. They won’t turn a FWD economy car into a rear-wheel-drive sports car. But they will make your car feel more connected, more precise, and more fun.
Driving isn’t just about speed. It’s about control. Strut braces and sway bars don’t make your car faster on paper. But they make you feel faster - because you’re more in control. You trust the car. You can push harder. You enjoy the drive more.
On a rainy Tuesday in Bristol, driving a modified Golf through the Mendips, that feeling matters more than any horsepower number.
No, they don’t. In fact, they usually make the ride firmer. Strut braces reduce flex, which can transmit more road noise and vibration. Sway bars reduce body roll, which can make the car feel stiffer over bumps. If comfort is your top priority, stick with stock. These upgrades are for drivers who want better handling, not a smoother ride.
Yes, you can. But if your shocks are worn out, the benefits will be limited. Worn shocks can’t control the movement the sway bar is trying to manage. You’ll feel the improvement in cornering, but the car may still bounce or feel unstable over bumps. For best results, pair sway bar upgrades with good-quality shocks or coilovers.
They’re less critical than on front-wheel-drive cars, but still helpful. In RWD cars like the BMW 3 Series or Nissan 370Z, front strut braces improve turn-in sharpness and reduce steering vagueness. Rear strut braces are rare and mostly used in track builds. For most street RWD cars, a front brace is enough.
Generally, no. Strut braces and sway bars are bolt-on parts that don’t modify the engine, transmission, or ECU. Under the Magnuson-Moss Warranty Act (in the US) and similar consumer laws in the UK, manufacturers can’t void your entire warranty just because you added aftermarket parts - unless they can prove the part caused the specific failure. Still, check your warranty terms if you’re unsure.
If your car leans noticeably in corners, or if you feel like the tires lose grip before you expect them to, your sway bar is likely too soft. If you’ve upgraded tires or lowered the car, that increases roll stiffness - and your factory sway bar may not keep up. A simple test: drive a familiar corner at moderate speed. If the car feels like it’s tipping over, a thicker sway bar will help.
Comments
Patrick Tiernan
Bro just put on some tires and stop overthinking this like its some sacred ritual
November 4, 2025 at 04:29
Patrick Bass
Strut braces do improve steering feel, but only if the chassis is actually flexible enough to warrant one. Many modern cars have sufficiently rigid structures already.
November 4, 2025 at 09:10