In 2013, Empire Bicycles and Renishaw pioneered 3D printing technology in cycling, but what happened next?
A collaboration with 3D printer manufacturer Renishaw, Empire Bicycle Company’s MX-6 Evo has become the world’s first titanium bicycle made entirely from 3D printing. It was manufactured in 2013 and laid the foundation for what would become one of the most important technologies in the bicycle production process. That year, the advent of the Hope HB.T track bike helped the British team win seven Olympic medals. This revolutionary trail bike has also attracted people’s attention.
Renishaw worked with Empire Bicycles to optimize the MX-6 Evo’s tube design to enable 3D additive printing, an improvement it says reduces weight by 33% without sacrificing strength.
This isn’t the first time Empire has used innovative manufacturing techniques: the aluminum alloy AP-1 downhill bike was launched as far back as 2007, when welding technology was still the norm and materials in carbon fiber had not yet entered the realm of downhill mountaineering. But the MX-6 Evo made the brand famous and promoted the development of 3D printing technology in the bicycle field.
A timeless miracle of 3D printing
Additive printing technology means that the bike’s components are created by adding layers of material, ‘printed’ by Renishaw’s AM250 machine.
Initially, Renishaw and Empire Bicycles agreed to 3D print the bike’s seat tube, but after successfully experimenting with this part, the two companies decided to try printing the entire frame.
This 3D printer has a print height limit of 300mm, so the bike frame must be printed in sections and then glued together. The frame consists of separate head tubes, top tubes, shock mounts, down tubes and bottom bracket, which are glued together using Mouldlife glue. To make the connection strong enough, various parts of the frame use a mortise and tenon design, with smaller tube sections “sliding” into the larger openings.
Frame modification made easy
This production technology does not rely on the expensive molds used in carbon fiber, nor the jigs and tools used in the design of aluminum frames, so changes to the frame design can be made quickly and profitably. If the bike’s geometry needs to be updated or customized to a rider’s specific needs, fine-tuning can be done without reworking the entire manufacturing process. It’s an intriguing prospect, one that resonates deeply with Atherton Bikes.
Each model is available in no less than 22 standard sizes – and custom geometries are available if necessary – which is a big advantage of 3D printed bicycle frames.
The finished product is light and strong
According to Renishaw, 3D printed titanium alloys are denser than aluminum alloys (4 grams/cubic centimeter for titanium and 3 grams/cubic centimeter for aluminum). At first glance, this means that a 3D printed titanium bike will be heavier than an aluminum bike.
However, through an intelligent design process, using the complex shapes that 3D printers can create, it is possible to remove any material that does not affect the strength of the bike and reduce the use of materials, thereby significantly reducing the total weight in relation to the bike. Aluminum alloy frame actually reduces weight.
For the MX-6 Evo project, Empire and Renishaw managed to reduce the overall frame weight by 700 grams, from 2,100 grams to 1,400 grams by switching from welded tubes to 3D printed titanium.
However, the strength of the frame has not been compromised. The MX-6 Evo has been tested and passed the EN 14766 standard (50,000 cycles at 1,200 N of force), but both brands want to go further. Even with testing six times the standard, the frame still showed no damage, indicating that the 900 MPa (megapascal) tensile strength of the titanium alloy is in full effect.
Additionally, the density of the 3D printed titanium alloy material is approximately 99.7%, which is much higher than that of the cast metal previously used by Empire Cycles.
Why didn’t it succeed in the market?
It’s hard to say, but we do know that Empire Cycles disbanded on September 22, 2020, during the COVID-19 pandemic. While the outbreak is unlikely to be the direct cause of Empire’s disbandment, the brand’s last social media update was posted over six years ago. Although the brand’s website is still operational, this shows that there are already worrying signs for the company’s operations ahead of 2020.
While there was never an opportunity to purchase a 3D printed Empire bike, the brand’s investment in innovative manufacturing technology has paved the way for other brands to create their own 3D printed bikes. 3D, first Robot Bikes and now Atherton Bikes with its much-loved AM. Models 130 and A.150. Other manufacturers, including Pivot’s Phoenix DH prototype bike and Specialized’s prototype demo, have also used 3D printing technology to prototype new models. Empire’s collaboration with Renishaw was therefore truly ahead of its time.
Article source: bikeradar Author: Alex Evans
