Body Overview: Doors
The F01/F02 has aluminum doors with sheet-metal shell window frames. The advantages of this configuration are as follows:
- Improved visibility to the outside and upward
- Window frames look lighter and slimmer when the doors are closed
- When the doors are open, the window frames look solid with a high-quality appeal
- More light can make its way into the passenger compartment
- Interior impression with improved feeling of space.
Front door
The doors are made of large, sheet-metal shells to transmit force. The corpus of the door is characterized by high rigidity and component quality, ensured by the closest possible tolerances. Numerous advantages derive from this make-up:
- Compliance with the highest requirements for rigidity at the window frames, because the frame is a single section made of only two sheet-metal parts with minimum dimensions and good manufacturability
- Implementation of the premium design/form language in the exterior by realization of extreme deep-draw dimensions and a new component separation (hinge reinforcement and door inside panel)
- Maximum geometrical stability of the individual parts with one-piece door inside panel (window frame and door corpus)
- Lowest possible number of components for the door structure
- Laser welding and structural adhesive bonding as the joining technologies of the door structure.
Rear door
BMW has often used aluminum door structures in the past, for example for the Z8. Until now, however, aluminum doors were manufactured only for models produced in relatively small numbers of units.
The development objective for the F01/F02 door structure, therefore, was to implement a concept for an aluminum door that can be manufactured in larger numbers at acceptable costs.
However, aluminum is not as easy to shape as steel, so aluminum sheet shell parts are much more difficult to manufacture than counterpart steel components, particularly when the deep-drawing depths are considerable.
Despite these difficulties, the development of a new structure concept with large shells to transmit force sufficed to improve the manufacturability of the components, without necessitating a departure from the proven sheet-metal shell structure. A new cross-section at the window frame achieves high rigidity and good manufacturability; there are only 2 parts and dimensions are minimized. In this way, the intensive form language typical of BMW's exterior lines is carried over into the material aluminum, bringing dimensional minimization to the visually sensitive area of the window frames and utilizing high deep-draw depths to preclude the possibility of taking up more space.
As regards the interior parts of the doors, it is noticeable that unlike the E65, there are no airbags in the door trim. Again at variance with the E65, the outside mirrors can be removed without the necessity of removing the door trim.
The sound-deadening mats and the fasteners for the wiring harness in the door are also of new design. The installation and removal of the exterior door handle are slightly more difficult than is the case with the E65.
Window lifts and locks are similar to those of the E65. A new roller sunblind is a feature of the rear door. The mounting elements are of modified design.