How Convertibles Work

Soft Top

Part of the Honda S2000's roof structure
Part of the Honda S2000's roof structure

The roof on the Honda S2000 roadster is fairly typical of convertible roofs. It is power operated, but requires the driver to manually latch and unlatch it from the windshield.

One switch on the dashboard operates the roof. To lower the roof, you release the latches and then press and hold the switch in the open position. If the windows are up, they will roll down before the roof starts to move. The roof will then fold itself back into a compartment behind the seats.

A motor that turns a gear on each side of the car powers the mechanism that raises and lowers the roof. The gear engages a bracket that has gear teeth cut into it (much like the mechanism used in power windows). This bracket is connected to the main structure of the roof. As the gear turns, it moves the roof into position.

The motion of the roof and the positioning of its different parts is completely determined by the geometry of the roof structure. A scissors-like linkage is formed by a set of metal arms and brackets that are linked together by pins. The linkage folds down into itself when the roof is open, and expands to form the structure of the roof when the roof is closed.

Once the roof is closed, the clips clamp it securely to the windshield and seal any air gaps.

The roof on the Honda S2000 is soft, and the rear window is made of clear, flexible plastic. On the S2000's roof, the window actually folds to make the roof more compact. Some larger convertibles have glass rear windows that can't fold. On some convertibles, the rear window even has a defroster.

In the next section, we'll take a look at a different kind of convertible roof -- a retractable hardtop.