Quick Info
Model
450, 451, 452
Estimated Cost
60-120€
Difficulty
Intermediate
Time Required
20-30 min
Safety Notes
The "Extended Bolt" Rule: If you are using pass-through spacers, you must use longer bolts. The rule of thumb is that the bolt must have at least 6.5 to 7 full turns of thread engagement into the hub. Using stock bolts with a spacer is extremely dangerous as they will not have enough "bite" to hold the wheel.
Hub-Centricity: Never use "Universal" flat spacers. Smart cars rely on the center lip of the hub to support the weight of the vehicle. Ensure your spacers have a matching lip (Hub-Centric) that fits your wheel perfectly.
Fender Clearance: After installation, check that the tires do not rub against the wheel arches (fenders) when the steering is at full lock or when the suspension is compressed. Rubbing can lead to sudden tire failure.
Vibration Check: If you feel a vibration in the steering wheel or seat after installation, stop immediately. This usually means the hub wasn't cleaned properly, the spacer isn't seated flat, or a wheel bolt has loosened.
Retorque Requirement: Aluminum expands and contracts differently than steel. You must check the torque of your bolts again after the first 100km (60 miles) of driving.
Step-by-Step Guide
Introduction
Whether you want to improve your Smart’s cornering stability or you simply hate how the wheels sit tucked too far inside the arches, wheel spacers are the most cost-effective way to transform your car's presence. By pushing the wheels outward, you increase the car's "track width," which directly translates to less body roll and a much more "planted" feel during spirited driving.
On a Smart Roadster (452) or Fortwo (450/451), spacers don't just add performance—they fix the proportions, giving the car that aggressive, wide-body stance that the factory setup often lacks. This is especially noticeable on the Roadster, where the large wheel arches can make even the standard 16-inch or 17-inch wheels look "lost" without proper spacing. By filling that gap, you achieve a flush look that aligns the tire sidewall with the fender edge.
However, because this modification involves the only parts connecting your car to the road, precision is everything. Improper installation can lead to dangerous vibrations, premature wheel bearing wear, or even wheel detachment. This guide is designed to walk you through the professional installation process—from the critical "Extended Bolt Rule" to hub preparation—ensuring your Smart is as safe as it is stylish.
Preparation and Initial Loosening
Park the vehicle on a level, solid surface. While the car is still on the ground, use your socket and breaker bar to slightly loosen the wheel bolts on the axle you are working on. Do not remove them yet; simply break the initial tension.
Lifting and Hub Cleaning
Jack up the car and immediately secure it with jack stands. Remove the wheel bolts and the wheel entirely. Use a wire brush and brake cleaner to scrub the mounting surface of the brake drum or disc until it is completely clean and free of rust.
Seize Prevention and Spacer Seating
Apply a thin, even layer of copper grease to the hub surface to prevent the aluminum spacer from bonding to the iron hub. Slide the hub-centric spacer onto the hub, ensuring it sits perfectly flush against the surface without any gaps or play.
Mounting the Wheel and Hand-Tightening
Lift the wheel onto the spacer's hub-centric lip. Start the extended wheel bolts by hand to ensure they are not cross-threaded. Hand-tighten all bolts in a star pattern until the wheel is held firmly against the spacer.
Final Torquing and Safety Check
Lower the car until the tires touch the ground enough to stop them from spinning. Use a Torque Wrench to tighten each bolt to 120 Nm in a star pattern. Perform a final visual inspection to ensure the wheel is centered and has proper clearance from the bodywork.
