June 28th, 2023
THOK E-Bikes has always invested substantial resources in research and development. The bikes in their range are not built using open mold frames but are all designed from scratch. This entails crossing unexplored territory in the development phase.
THOK's goal is to create innovative, high-performing, and fun e-bikes characterized by a certain uniqueness and Italian style, signed by Aldo Drudi’s D-Perf.
All models in the range have distinctive features resulted from meticulous work and study, technical testing, and countless hours of trail testing. Over the years, many winning solutions have emerged from this constant research and the company's know-how:
- the MIG's low gravity center, achieved by positioning the battery under the down tube, optimizes weight distribution and makes it one of the most intuitive, high-performing, and fun all-mountain e-bikes in the industry;
- the solid front end of the TK01, which provides precision in handling and stability when tackling rough terrain at high speeds, as well as the maximum verticalisation of the integrated battery to maintain a low gravity center;
- the geometry of the GRAM, representing the highest expression of the enduro concept with its technical climbs and descents, achieved through careful calculations and a balance of extreme angles, the result of in-depth studies on carbon fiber.
THOK has always been synonymous with study, research and innovation, and now it is also a pioneer in the use of new technologies for the development of e-MTBs.
In collaboration with the company "Materialise," it is the world's first e-bike brand to have experimented with 3D printing in metal (Selective Laser Melting - SLM) to create a fully functional prototype of a full-suspension e-MTB made of aluminum.
A moulded but perfectly rideable prototype
"THOK Project 4" (P4 is the temporary acronym until the bicycle takes its final form and name) is the embryo of what will become the first "light e-MTB" in carbon fiber by THOK in 2024, featuring a Bosch SX motor and battery modularity (400 / 545 / 725 Wh + range extender).
The development is currently underway, and some technical choices are still being evaluated, such as integrated or semi-integrated battery, component configuration, and geometric decisions. However, the frame created through 3D prototyping is already being tested on the technical trails of Finale Ligure and the Alba (THOK E-Bikes headquarter).
Let's delve into some aspects of this innovative prototyping technology.
Advantages and difficulties
The aim of rapid prototyping with 3D printing is to produce working models, which allow geometry, suspension and component integration to be tested.
SLM makes it possible to make parts light enough to simulate the weights of the final carbon-fibre bicycle.
“It is impossible to obtain a running prototype and reproduce the necessary battery and motor integration with a traditional method. There are components that are made by hydroforming, which require moulds, and which would not otherwise be prototype-able. Even carbon prototypes are not functional, they do not hold up on long field testing sessions. In this sense, the first fully moulded full-suspended e-bike we made solves a big problem”, explains THOK industrial designer Luca Burzio, who follows the projects from the engineering side.
Technology, materials and the right partner
For such a delicate transition, THOK looked for a partner, a travelling companion of excellence. The choice fell on Materialise, a Belgian company with offices in 20 countries around the world. They specialise in 3D printing for the aerospace, automotive and medical sectors.
The technology is Selective Laser Melting (SLM): this is an additive manufacturing procedure that uses lasers to melt metal powder. For the Thok P4, an alloy of aluminium and silicon (AlSi10Mg) was chosen, as it is the most suitable in terms of strength, thermal properties, weight and post-machining flexibility.
The challenge faced by THOK and Materialise
“In the past, we used to make successive revisions of projects. We studied no less than three prototype frames before making the first running model. With the Thok P4, the first revision is already a model with the thicknesses and distances typical of carbon fibre, produced to be assembled and above all pedalled with a feeling very close to the definitive bike”, explains THOK CEO Stefano Migliorini.
This challenge has confronted THOK and Materialise with problems never faced before and has been a learning curve for both of them, especially when it comes to the interaction of metal moulded parts, as well as the machining of the kinematic mechanism housings and component interfaces.
"The project with THOK allowed us to extend our experience into the bicycle sector and set the metal 3D printing to a new level. This collaboration gave us the opportunity to refine our metal additive manufacturing capabilities to find answers to the precise requirements of the Italian company”, explains Simone Cannella, business development manager at Materialise.
The future of 3D printing is yet to be seen, but the experimentation carried out by THOK and Materialise is a pioneering chapter in this story that will bring innovation to the entire global e-bike industry.