The Smart Roadster and Fortwo (450) were designed with a "safety-first" philosophy, which often meant engineering a fair amount of understeer into the factory suspension. While the original 19mm front sway bar (anti-roll bar) is competent for city driving, it quickly reaches its limit during spirited cornering or track use. As the chassis leans, the inside tire loses contact patches, and the front end begins to "push" wide—a sensation every Smart owner knows all too well.

Upgrading to a 22mm Performance Sway Bar is widely considered the single most effective mechanical change you can make to the front-end geometry. By increasing the bar diameter by just 3mm, you aren't just adding a thicker piece of steel; you are exponentially increasing the torsional stiffness of the front axle. This keeps the car significantly flatter through high-speed transitions, allowing the tires to maintain a much more consistent contact angle with the asphalt.

This upgrade doesn't just reduce body roll; it fundamentally sharpens the car's "turn-in" response. The delay between turning the steering wheel and the chassis reacting is virtually eliminated. When paired with high-density polyurethane or heavy-duty rubber bushings, the 22mm bar transforms the Smart from a nimble city car into a precision-focused cornering machine.

In this guide, we break down the installation process—from navigating the tight clearances of the front subframe to the essential lubrication techniques that prevent the "squeaking" often associated with stiffer setups. If you’re looking to kill understeer and give your Smart the "bite" it deserves, this is the upgrade you’ve been waiting for.