Avalanche Design Journal · Product Development
When people evaluate an automotive component, most of their attention goes to the surface they can see. In automotive development, this visible exterior is commonly referred to as the A side. It defines the form, reflections, character lines, and overall appearance of the part.
The B side is the structure behind that visible surface. It is where mounting points, ribs, reinforcements, flanges, hardpoints, and structural interfaces are developed.
At Avalanche Design, both sides matter equally. A beautifully designed Class A surface is only useful if the structure behind it can maintain that shape, support real-world loads, and fit the vehicle correctly.
The B Side Supports the Surface
Large automotive panels experience much more than their own weight. Aerodynamic pressure, vibration, heat, hinges, latches, gas struts, mounting hardware, and normal vehicle movement all introduce loads into the structure.
A panel does not need to break to be poorly engineered. If the B side lacks sufficient stiffness, the visible A side can flex, vibrate, or develop waviness. Reflections begin to distort and broad surfaces can appear soft or melted.
This is especially noticeable on large aftermarket carbon fiber panels such as hoods, engine lids, and other body panels. What appears to be an A-side surface problem can actually originate from inadequate support underneath it.
That is why we develop the B-side structure together with the exterior surface rather than treating it as something to add later.
Strength Is Not the Same as Stiffness
Strength determines whether a component can withstand a load without failing. Stiffness determines how much it moves while carrying that load.
For an automotive body panel, both matter.
A carbon fiber panel may be more than strong enough to survive its expected loads and still be unacceptable if the surface visibly deflects at speed or vibrates while the vehicle is idling. Ribs, reinforcements, and structural geometry therefore have to be positioned according to how forces actually travel through the component.
The goal is not simply to add more material. It is to maintain the intended Class A surface with an efficient lightweight structure.
Carbon Fiber Requires Different Engineering
Carbon fiber offers exceptional strength and stiffness for its weight, but it behaves very differently from aluminum.
This becomes particularly important around concentrated loads such as hinges, latches, bolts, and gas-strut mounts. Instead of allowing a small area of laminate to carry the entire force, the load needs to be distributed into a larger region through reinforced hardpoints, additional laminate, ribs, inserts, and controlled structural transitions.
This is why we do not simply transplant the OEM B-side structure into our Audi R8 roof scoop. The new carbon fiber panel requires its own structural solution based on its geometry, material properties, and load paths.
Audi R8 Carbon Fiber Roof Scoop
Our Audi R8 roof scoop and engine lid is a good example of this approach.
The complete engine lid is replaced by a lightweight carbon fiber assembly with an entirely new exterior design. Its B side is developed specifically around that new geometry and carbon fiber construction.
The hinge areas require dedicated reinforcement. The latch locations need structures that spread concentrated loads into the surrounding laminate. Gas-strut mounting points require reinforced hardpoints, while the larger areas of the panel need enough stiffness to preserve the Class A surface above them.
Heat from the Audi R8 engine bay, aerodynamic pressure, vibration, and repeated opening and closing loads also have to be considered. Structural analysis and load evaluation help determine where reinforcement is necessary and where additional material would simply add unnecessary weight.
Even the Hardware May Need to Change
Changing the panel can also mean changing the hardware around it.
The factory Audi R8 gas struts were designed around the weight of the much heavier OEM engine lid. Our carbon fiber roof scoop assembly is significantly lighter, so using the original strut force would introduce unnecessary load into the new structure.
For that reason, we also evaluate components such as gas struts, hinges, latches, and mounting hardware as part of the complete system.
This is why the B side of our roof scoop is engineered specifically for the new carbon fiber panel rather than copied from the OEM engine lid.
Designing the Side Nobody Sees
The A side gives an automotive component its visual identity. The B side is what allows that design to survive as a physical product.
It supports the surface, controls deformation, carries mounting loads, maintains fitment, and allows the component to function correctly over time.
For Avalanche Design, OEM-level automotive development does not stop with a beautiful Class A surface. The structure behind it has to be designed with the same level of intent.