The chassis and suspension: In the service of dynamism
The chassis of the CLA features a McPherson front axle and an independent multilink rear suspension, featuring three control arms and one trailing arm per wheel. This means that longitudinal and lateral dynamics are virtually independent of one another. Direct Steer is standard for all versions.
A CLA-specific feature is the elastic decoupling of the rear axle carrier, which benefits ride comfort. The measures include rubber bearings vulcanised onto the anti-roll bar and the elastomer coating of the coil springs, which produces an effective noise de-coupling between the vehicle body and rear axle.
The connection of the damper to the vehicle body is via an aluminium bearing with a soft universal joint that contributes to reducing friction in the damper, and consequently helps responsiveness. Wheel carriers and spring links are made of aluminium, in order to reduce the unsprung masses.
Two suspension set-ups are available: the comfort suspension and the optional sports suspension for sporty yet comfortable handling. The latter entails lowering of the body by 15 mm (front) and 10 mm (rear).
Irrespective of the selected chassis, all CLA variants come with the Direct Steer system. This electromechanical power steering offers improved feedback to the driver in comparison to conventional systems and makes an important contribution towards overall efficiency, as the steering assist function only requires energy when the steering wheel is actually turned. Additionally it enables various steering assistance functions which are activated by the ESP® control unit. These include countersteering in case of oversteering, corrective steering when braking on road surfaces offering different levels of grip (split-friction braking), mitigation of the extent to which the front-wheel drive influences the steering and compensation for crosswind and road gradients.
With all engine variants, the CLA-Class comes with disc brakes on all wheels. The callipers on the rear axle and the brake boosters are made of aluminium. A particularly convenient feature is the HOLD function, which is familiar from the larger model series: when stopping, for example at traffic lights, the driver merely has to press the brake pedal slightly more firmly and the brake will remain engaged until they move off again. The brake is released automatically when the driver steps on the accelerator. On versions with manual transmission, the Hill Hold function automatically prevents the vehicle from rolling back unintentionally when moving off on a slope.
The CLA-Class is equipped with an electric parking brake, which operates by means of actuator motors acting on the callipers of the rear axle. The parking brake is activated via a button under the light switch on the left of the dashboard. This creates additional space in the centre console, as the handbrake lever is no longer required. When the button is pressed at speeds of over four km/h, the parking brake acts as an emergency brake, activating all four wheel brakes via the ESP®'s hydraulic unit.
In conjunction with the 7G-DCT automatic transmission, the parking brake offers a particularly convenient mode of functioning: when the driver accelerates sufficiently after fastening their seat belt, the parking brake is released automatically.