Until recently, every cyclist who wanted a new bicycle had two options: buy it from one of the big brands, with a monocoque frame available in a range of standard sizes, or choose a custom-made frame with the tube-to-tube construction technique. This type of frame uses tubes that are cut and bonded, and then the joints – or knots – are wrapped with carbon fiber.
This has some inevitable drawbacks in terms of rigidity. Today, the innovative Italian brand EXEPT, which is based in Finale Ligure, is offering cyclists a third way. EXEPT has developed a process that combines the advantages of both traditional approaches to create customized monocoque carbon fiber frames. The monocoque production technique patented by EXEPT uses movable molds to create monocoque frames without disrupting the carbon fiber. We asked Alessandro Giusto, co-founder of EXEPT in charge of innovation and testing, to explain the production technique in more detail.
“The key to economic sustainability in the production of bicycles is the cost of the tools. A mold can cost up to fifty thousand, sixty thousand euros, so only the big brands are able to make a mold for every size. However, we at EXEPT have developed an innovative technology to build every size with just one adjustable mold.”
The largest Italian brand produces fifteen thousand high-end bicycles a year, while the business plan of EXEPT projects to produce up to three thousand pieces a year in five years.
“The clear and intuitive visualization capacity of the Femap™ software helps the user to better understand the model and provides advanced reporting tools for data extraction. Consequently, the construction of the model is intuitive, fast, and streamlined.”
The mobile mold concept was developed by the three founders and reflects their passion for cycling. Alessandro Giusto previously worked at a world-leading brand in the production of automotive brakes, and also has experience in the aerospace industry and in the design of carbon fiber components in the sports industry.
The co-founder and CEO of EXEPT is Alessio Rebagliati, a former colleague of Alessandro’s and an expert in the design and production of aeronautical carbon fiber parts. The third founder, Wolfgang Turainsky, is a German engineer who has worked for some of the most important cycling brands in the world. It took two years for the trio to build prototypes that demonstrated the feasibility of the production process. Before being analyzed with element modeling tools (FEM), the first frame was given to the former professional cyclist, Damiano Cunego, for testing. Once it received the technical approval, EXEPT presented the project to an investment fund group that provided the necessary resources to move on to detailed design, testing and certification.
“The bike was designed from the outset according to this new concept of frame building. However, initially we did not focus on carbon fiber, since the design of composite materials is a complex activity that requires full-time work. Once we had obtained the funds to finance our innovative idea, we were able to abandon our previous jobs and immerse ourselves in the new business.”
In his experience as an engineer in the aerospace and sports industries, Alessandro Giusto had the opportunity to get to know the Simcenter™ Nastran® software, in particular element modeling and the pre and post processing abilities of the Femap™ software by Siemens.
“From 2007 to 2013 I learned advanced skills with these tools. At that time I was responsible for the R&D department of a large company, where non-linear analysis is performed using different tools.”
After optimizing frame rigidity, the EXEPT engineers focused on carbon fiber design. To define the carbon lamination sequence, Giusto and his colleagues set the structure 82 times, achieving extraordinary results.
“We purchased Femap™ in September 2017 and started laminating carbon fiber in January 2018, delivering the complete carbon lamination sequence in late March. With Femap™ it took less than three months for more than 80 iteration cycles. Considering that the average delivery time of a branded bike is two years, it’s a great result. We launched our model in July, having started working on it less than a year before, and this was only possible thanks to the simulations, we didn’t have to make any physical iterations. There is currently nobody in the Italian cycling industry that has similar tools.”
The advantages of the software are further reinforced by the long relationship between EXEPT and SmartCAE, the Siemens partner that supported EXEPT from its infancy. With the expert guidance of SmartCAE, the skills of the three founders, and the advanced FEM functions of Femap™, EXEPT is able to perform sophisticated and critical simulations, static and dynamic tests, and simulations of complex mechanical events such as crashes and impact tests.
All this makes EXEPT an avant-garde brand from a design and technical point of view, a new level of excellence ready to revolutionize the cycling world.