The NERA e-motorcycle started with an idea: create a functional prototype that revolutionizes mobility and can be produced entirely with 3-D printing.

With Marco Mattia Cristofori in the design lead, BigRep engineered the NERA e-Bike from the ground up, disrupting traditional design, engineering and production in every aspect. The result is a 100% customizable, functional prototype, designed and produced with more time- and cost-efficiency than previously imaginable.

In building NERA, BigRep’s designers and engineers didn’t simply adapt existing motorcycle designs; instead they envisioned a bike designed for large-format fused filament fabrication (FFF) technology, setting a benchmark for truly creative design and breaking the limits of traditional mindsets.

How Additive Manufacturing Technologies Disrupt Existing Possibilities

1. Ideation: First, BigRep worked on the basic bike aesthetics. From the basic mechanical functionality to a unique design language, it started sketching in five design iterations. 3-D printing changes the perception of design language and allows total freedom in terms of design: bionic, organic, edgy — any designs are only one thought from reality.
2. FFF-based design: BigRep ideates especially for the FFF technology with its unique possibilities: Design and functionalities are exclusively FFF-based and don’t work with any other production technology. Prototyping for standard manufacturing methods has extremely limited design possibilities when it comes to mechanical functions as well as to the design language of objects.
3. Design process: First, BigRep arranges the functionally relevant core parts, then designs the outer shell, translating the chosen design language into the functional parts. BigRep decided to pursue a low polygon/ stealth design language, which allowed it to avoid top layers that can be a weakness of FFF printing.
4. Embedded electronics: Battery, motor, cable and control systems are not printed. The motor is electric, since traditional combustion engines cannot be embedded in polymer objects. The electronics can be adjusted individually and are integrated as a modular system that allows individual settings.
5. Materials: NERA is printed with BigRep Pro Flex, BigRep ProHT, BigRep PLA and BigRep PETG materials. While BigRep uses ProHT for rigid parts, PLA for color details and PETG for the light reflectors, Pro Flex allows the company to embed functionalities in a unique way. Tires, bumper, seat and handles are printed with the flexible material and fulfill functions that usually require complex mechanical constructions, such as hydraulic, shock absorbing suspension systems. The strength and elasticity of the material allowed BigRep to come up with completely new design approaches that replace the traditional mechanical components. A horizontally embedded Pro Flex suspensor with honeycomb structure, for example, replaces a traditional hydraulic system integrated in metal fork steering systems for motorcycles.
6. Forkless steering: Instead of a fork steering, NERA has eight pivot points, clamping vertically instead of assembling the fork to rotate the wheel on a horizontal axis.
7. Print parameters: BigRep’s design team used 12% infill almost everywhere. This was determined by testing several small portions and then determining that 12% is the perfect fit for structural stability.

In total, the design features included 15 fully 3-D printed parts:

• Fully-functional, full-scale 3-D printed prototype
• All parts printed with BigRep printers (except electronics), including body, rims, tires, steering, seat, headlight and shocks
• Flexible parametric bumper replaces suspension as a shock absorber
• Custom-fitted seat and chest rest printed with flexible thermoplastic
• Airless tires with customized tread printed with flexible thermoplastic
• Front tire has an arch structure for a softer, smoother ride
• Back tire has a stronger hexagonal structure for load-bearing parts.

More than just an exercise in what can be achieved with 3-D printing — and specifically FFF printing with BigRep technology — the NERA shows that the low cost and fast results of additive manufacturing allow designers to immediately test prototypes and rapidly produce iterations of experimental engineering. The NERA also illustrates the massive benefits that 3-D printing offers to produce functional parts, particularly for unique- to small-series production, by reducing lead times and costs, optimizing supply chains and limiting dependency on supplier networks.

Daniel Büning, co-founder and managing director of NOWLAB, explained, “Our NERA E-Motorcycle is the perfect example of the disruptive capabilities of additive manufacturing in the mobility sector. The bike is the result of a radical new approach to product development, seamlessly spanning digital simulation to custom manufacturing. Therefore, NERA combines several innovations developed by NOWLAB, such as the airless tire, functional integration and embedded sensor technology. We push the limits of engineering creativity to reshape additive manufacturing technology as we know it.”