Custom layup? The border between craftsmanship, engineering, and safety

GREGARIO’s philosophy is founded on the unique combination of bespoke craftsmanship and engineering ethos, and we understand the nature of this request. Theoretically, having a variable geometry mold that perfectly adapts to your measurements, extending personalization to the internal carbon layering might seem like the logical next step.

It is a fascinating idea, but this is where our artisan inspiration collides with our uncompromising engineering ethics: safety always comes first. On the road with our beloved bicycles, we already face a certain degree of risk from “external factors”; the last thing we need is to worry about our safety due to the bicycle itself!

ISO 4210 Validation: The Wall of Safety

Our current layup for the VERA AR aero-road model has been optimized to achieve high targets for stiffness-to-weight ratio (with priority given to stiffness). It is the result of intensive development with iterations between virtual environment simulation (FEM) and experimental bench and road testing.

However, even before these targets, the crucial aspect is not performance optimization: it is compliance with the ISO 4210 standard.

To offer VERA AR with complete safety, we have passed a series of rigorous static, impact, and fatigue tests prescribed by the regulation. These tests under extreme load conditions “validate” the design and the chosen stratification. The current layup is, therefore, designed specifically to pass these tests with ample safety margins.

What would happen if we modified the sequence and orientation of some carbon plies (the layup) to adapt them to a single customer’s weight or desire to shave off a few grams? The variation, even if seemingly minimal, could alter the frame’s behavior under fatigue or impact loads, transforming a certified product into an untested prototype.

The frame would be different from the validated one and thus non-compliant with ISO 4210. This would require a new validation or, alternatively, a waiver of responsibility from the customer. In good conscience, we are not willing to accept risks based on a customer’s “whim.”

When a frame is certified according to the ISO standard, it is the exact layup, in the tested geometry, that obtains the seal of safety. By testing a large size, it can be assumed with reasonable confidence that smaller sizes will respond similarly, as is standard practice in our industry. But changing the layup means producing a very different frame.

One might be tempted to consider a different approach for the opposite case: “oversize” customers who ask to add carbon compared to the validated layup, reinforcing critical zones based on our available structural analyses. While the logic is correct, experimental validation would still be missing, with all the safety, legal, and ethical implications mentioned above. This is a feasible path, but not without obstacles, and it would have to be evaluated on a case-by-case basis.

Our Vision: Models, Not Compromises

We recognize that cyclist needs can vary. For this reason, we might, in the future and if the specific demand grows significantly, develop several pre-validated layup variants (e.g., an “Oversize,” a “Max-Stiffness,” and an “Ultralight” variant) for our aero-road model and every subsequent model. However, each variant would require its own series of complete ISO tests and the associated development costs, which would be difficult to sustain.

Furthermore, beyond feasibility, we believe that this differentiation can be better expressed through the development of distinct bicycle models.

It makes no sense to design an aero-road frame with significant, aerodynamics-optimized profiles and then try to make it a featherweight by acting only on the layup. For us, optimization must start from a blank sheet. VERA AR was born aspiring to a certain type of experience, feel, and performance. When we decide to create an ultralight bike for climbers, we will put weight reduction at the center of the design from the ground up, starting with the choice of profiles and geometries, and certainly not limiting ourselves to removing a few layers of carbon.

The Hidden Personalization

Finally, it is essential to remember that the layup of your GREGARIO frame is already, in a sense, customized.

Our process involves the use of over 300 carbon fiber shapes (plies) to create a single monocoque frame. Since our variable geometry mold produces unique geometries for each customer, a significant portion of these shapes is specifically adapted to the size of each frame in production, all while maintaining the architecture and robustness of the ISO-validated layup.

The engineering and safety we offer you with the validated layup remain our absolute standard, and we are not willing to jeopardize your life for an excessive indulgence in “craftsmanship.”