Category: Harley Davidson News

Motorcycle racing is an exhilarating sport where victories can be counted in microseconds. An edge can sometimes rest upon millimeters of tire gripping the track.

Engineers and designers work diligently to eliminate any unnecessary weight, all while ensuring parts remain resilient enough to endure falls and continue functioning effectively.

When Harley-Davidson Factory Racing (HDFR) reached out for assistance in developing and producing components for their involvement in the MotoAmerica King of the Baggers racing series, we eagerly embraced the opportunity. Crafting motorcycles of this caliber (weighing over 600 lbs) involves continuous iterations that lead to enhanced safety and performance metrics.

The ability to efficiently iterate and swiftly manufacture was essential to HDFR’s goals. This collaboration underscored the advantages of partnering with a singular, digital manufacturer for everything from prototyping to the production of usable parts.

The crucial design objectives were to enhance safety and maximize cornering speeds for bikes capable of exceeding 180 mph. With as many as 14 turns per lap, even a half-degree improvement in lean angle can drastically decrease race completion times.

3D Printing: A Viable Solution

Among the components developed for HDFR was a seemingly straightforward exhaust pipe. Running alongside the bike, the original design encountered issues with tight turns at high speeds, occasionally scraping against the ground and causing loss of control. Refining this design had the potential to yield significant performance enhancements.

Working alongside our engineers, the design team from HDFR examined various manufacturing methods for their prototypes before ultimately opting for 3D printing—specifically, direct metal laser sintering (DMLS).

Why Choose DMLS?

DMLS utilizes powdered metals in an additive manufacturing process, providing remarkable design flexibility along with the creation of robust metallic components.

In a sizable build chamber, at least one laser is employed to fuse metal powders, layer by layer. Once a layer has adhered to the previous one, the platform gradually descends, followed by another layer of powder being applied for continued fabrication.

After initial prototypes in stainless steel, HDFR opted for strong yet lightweight titanium for the final part. This material not only ensured durability but also offered outstanding resistance to corrosion—a crucial factor as the bikes must perform well across varying weather conditions. While titanium typically incurs higher costs, it was imperative that the part could withstand the abrasions of the racetrack while also significantly reducing weight.

Subsequent cycles of prototyping and testing allowed the team to refine the design based on insights from the riders. Each version was evaluated, leading to the creation of a production-ready component. With 3D printing’s speed in delivering complex parts, the design team could continuously improve the outcomes based on real-world testing.

The updated pipe design improved lean angles, enabling the riders to navigate turns faster without risking damage to the exhaust system.

Machined Components for Protection

While refining the exhaust system stood out as a major achievement for rapid prototyping, another critical part was designed to protect the shift assembly—the bike’s vital gear-change mechanism located on the left side. Any damage to this assembly could severely hinder performance during races.

In a push for rapid iteration, HDFR realized just a few days before the race how critical it was to design a protective piece for the shift assembly. The objective was to ensure that if the bike tipped over, the shift skid would shield the assembly, allowing the rider to potentially continue the race.

Given the time constraints, 3+2-axis CNC machining was employed to fabricate the part from a block of aluminum 7075/T651/T6. The machining process was advantageous due to its precision and speed. As with the titanium exhaust, aluminum was selected for its strength, providing a lightweight yet robust solution.

The finalized design was submitted on a Monday, and the part was delivered to the Harley team just two days later, well ahead of the Friday qualifying sessions. This timing was fortuitous; rider Kyle Wyman experienced a slide during rainy conditions, scraping the skid against the pavement. The part functioned as intended, protecting the shift assembly and enabling Kyle to compete successfully in the subsequent race.

The Speed of Digital Manufacturing

A pivotal factor in HDFR’s triumph in the King of the Baggers series was the swift iteration enabled by digital manufacturing. Unlike traditional quoting methods, a digital quoting system provides rapid—if not instant—responses to requests for quotes (RFQs), along with critical design feedback for manufacturing. Without such insights, companies must engage in lengthy back-and-forth communications to refine part designs, which can be tedious and unproductive when operating under tight deadlines.

Digital manufacturing facilitates the rapid development required to keep products ahead of competition, efficiently transitioning from prototypes to final parts and ultimately crossing the finish line.