Since 2016, Bastion Cycles as been a pioneer in applying 3D printing to custom bicycle production (with internal Renishaw metal systems). The Australian company just unveiled the latest development at the Handmade Bicycle Show Australia (HBSA) in Melbourne: a fully integrated 3D printed bicycle cockpit system incorporating an internally routed fork and one-piece bar-stem made entirely in-house at their facility in Fairfield, Australia.
For several years the company has been planning to create such a system, citing the ability to tune the fork offset for further optimized handling for each rider and further improved front-end ride quality through controlled flex and damping characteristics as the main motivation for the development. However, hiding the hoses and wiring for an appearance benefit has been something which has increasingly been requested of them by their client base in recent months.
Ben Schultz, Managing Director, Bastion explained further: “When we are designing a custom bike for someone, fork offset and head tube angle are two of the most important variables in getting the bike to handle the way we would like and the customer expects. Especially on smaller frames the limits on the fork offset can inhibit achieving this optimized handling condition while maintaining toe clearance. Now we can use whatever fork offset we need between 40 and 55mm depending on the design. To date, we have made use of aftermarket carbon fiber forks and bar-stems and we have felt there is a small, but noticeable disconnect in the ride quality between the front and rear of the bike. The new cockpit and the addition of our breakthrough technology to the fork and bar-stem extends the same beautifully refined and smooth ride quality to the front of the bike, matching the rear. The icing on the cake so to speak has been the ability to hide all the hoses and wiring which is something customers are increasingly asking for as it creates a much cleaner aesthetic and also delivers a small aerodynamic advantage.”
3D-Shaping it
Unlike many similar products on the market, their system utilizes a more traditional 11/8” upper headset bearing resulting in a more svelte and refined aesthetic and enabling them to maintain the existing styling of their bikes. James Woolcock, Engineering Director at Bastion provided additional details: “Even though most systems on the market use a larger 1.25” upper headset bearing we felt this was too much of a compromise on the visual weight at the top of the bike and not something we wanted to accept. Although extremely challenging from a technical perspective we are glad we persisted and the evidence is in the beauty of the end product.”
To facilitate the internal routing a D-shaped fork steerer tube has been used, but unlike other D-shaped steerer systems, the matching bore in the stem is also D-shaped. This assists routing of the hoses and wiring, but also means any loss of steering control in the event of a loose stem bolt is virtually impossible. Throughout the system a combination of 3D printed titanium alloy and carbon fiber is employed. However, unlike the tubing in their frames which is filament wound, Bastion has created a new process using hard tooling and pre-impregnated carbon fiber to manufacture the legs and steerer of the fork, and the crossbar of the bar-stem.
James Woolcock, Engineering Director, Bastion said: “When we looked at the more complex loading compared to the frame and in the fork in particular, we identified the need to use non-uniform and non-symmetrical lay-ups which is just not possible with filament winding. So we developed our own novel molding process and after months of trials are now producing what we believe are some of the highest quality carbon fiber components in the industry.”
NDTesting a 3D printed bicycle cockpit
The goal was always to obtain a high-quality end-product. The Bastion team worked closely throughout the development with Raoul Luescher from Luescher Teknik, a world renowned expert in Quality Control and Non-Destructive Testing (NDT) and Inspection of carbon fiber components with a background in the aerospace industry. In an industry first, the products will undergo Statistical Quality Control (SQC) involving Ultrasonic testing of 100% of the parts initially before reducing the number of parts scanned depending on the statistical variation found in the testing.
Manufacturing on Demand
Raoul Luescher, Owner of Luescher Teknik, added: “This has been something that I have been vocal about for many years having witnessed fork failures that have resulted in serious injury and death. Non Destructive Inspection and Quality Assurance methods such as ultrasound have been utilized in the aerospace industry on critical carbon composite parts for over 40 years. A bicycle fork is a failure critical item that deserves the same attention to detail and quality assurance processes not only in the design phase but in ongoing production. I am proud to work with the Bastion team on this fork and believe it is a significant step forward in bicycle industry quality.”
In light of recent high profile failures of integrated cockpit and fork systems, it is worthy of note that the Bastion system uses a bonded in titanium compression plug which significantly reduces the possibility of damaging the steerer through over-tightening and also removes any risk of galvanic corrosion. Likewise, with the bars, the drops sections are titanium and have been tested to double the recommended torque on the shifter clamp bolts with no signs of damage to the bars. Whilst not touting any specific numbers the company has identified there is a definite aerodynamic advantage through the NACA foil shapes of the legs of the fork and the crossbar of the bar-stem. As well as the increased aerodynamic efficiency from having the hoses and wires out of the free stream.
“We really tried to balance adding some aerodynamic benefits with the overall aesthetics and are extremely happy with where it has ended up”; continued Woolcock. “We definitely feel it achieves that optimal condition of satisfying both form and function.” Weight reduction was not a target for the development, but the products are competitive with other similar systems, the company stating 490g for the fork and 440g for the bar-stem.
Bastion Cycles, has been producing some of the finest and most desirable road bicycles in the world since 2016. The company pioneered the use of 3D printing in bicycle manufacture and are the only bicycle company in the world to have Titanium 3D printing capability in-house. Integrated Cockpit System Components Description Fork – 3D printed Titanium Crown and Dropouts. Carbon fibre legs and steerer tube. Dshaped steerer with internal routing. Bar-stem – 3D printed Titanium stem and drops. Single piece carbon fibre crossbar. Compression Plug – 3D printed Titanium. Bonded into steerer.
Tailored for the rider
The use of 3D printing means the components can be tailored to the customer. This results in an optimized position for comfort, aerodynamics and power output. With the ability to tune stem length and angle, bar width, and most importantly fork offset Bastion are able to create custom geometry like no other bicycle manufacturer in the world. Aerodynamics Improved through the removal of hoses and wires from the free stream and also through NACA foil shapes in the legs and crossbar.
3D printed in Grade 5 Titanium Alloy (Ti6Al4V) the components utilize topology and structures that would be otherwise un-manufacturable by conventional subtractive methods such as CNC Machining. Bastion Cycles are leaders in 3D printing end-use production parts with quality such that the components are finished naked without paint and are instantly recognizable by their metallic appearance.
Bastion’s use of a blend of carbon fiber and titanium in their products delivers a refined and smooth ride quality not found in other products. Developed in collaboration with and endorsed by Luescher Teknik. Raoul Luescher has been a vocal critic of quality control in the bicycle industry. His business Luescher Teknik repairs carbon fiber bicycles and regularly finds failures that are the direct result of manufacturing defects. Raoul has brought his knowledge of aerospace quality control and Non-Destructive Testing (NDT) to the development and ongoing Quality Control of the products.
The integrated cockpit system is available exclusively on Bastion framesets and has already been pre-sold to existing customers and is available for new customers to order now.
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Author: Davide Sher
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