Harley-Davidson Turns to Digital Manufacturing in Accelerated Timeline
Racing motorcycles is as much about geometry and physics as it is velocity. Riders negotiate sharp curves, aiming to balance their bikes on a thin strip of rubber, all the while trying not to exceed the coefficient of friction. With every movement, they urge their machines to lock into a track without slipping or scraping against pavement, which would inevitably lead to a crash.
The MotoAmerica King of the Baggers series pushes riders and their 600 lb. motorcycles to their limits. For racing teams, that means finding ways to ensure that their bikes can stay upright—and riders stay safe—despite the physical forces that try to deny a completed race. Recently, Protolabs had a chance to partner with the Harley-Davidson Factory Racing (HDFR) team to help design, revise and manufacture parts to improve their motorcycles. In this situation, super-fast iteration proved key to their success, as digital manufacturing enabled Protolabs to prototype and turn around end-user parts in record time, leading to improved motorcycle stability and resilience.
Tech-Enabled Quick-Turn Manufacturing
Digital manufacturing helps designers throughout the development and manufacturing process. It incorporates a digital quoting system with critical design for manufacturing (DfM) analysis and easy RFQ approvals. These fundamental features ensure that CAD models adhere to rules that permit fast production. From there, the digital file flows immediately to the production floor.
When iterating for a race taking place the next weekend, the quick flow through the manufacturing process is vital. HDFR turned to Protolabs for injection molded, machined, 3D printed and sheet metal fabrication parts needed in days, not weeks.
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Digital Manufacturing in Action
To illustrate the role of quick-turn manufacturing in high-pressure racing environments, let’s dive into the creation of two parts that played a role during the 2024 King of the Baggers season.
A key piece of every motorcycle is the shift assembly, located near the foot pedal on the left-hand side of the bike. The issue with the original equipment was that the assembly is susceptible to damage if a crash occurs and the bike goes down. A damaged shift assembly removes any opportunity to further compete.
HDFR decided that they needed a strong, lightweight cover to protect this vital part, but timing was critical as the qualifying events for the race were coming up in a few days. They chose to CNC machine the part, partially due to the time constraint, but also because machining permits manufacturing of smooth, organic shapes. It also achieves tight tolerances and fast manufacturing speeds.
Working with Protolabs, HDFR chose to use a block of aluminum 7075-T651/T6 as the part’s base material. It was a great match because the material is extremely strong and durable. HDFR uploaded the CAD model into a digital quoting system on Monday and had the part in hand by Wednesday—plenty of time to mount and test it.
The cover got a real-world test that weekend. Rider Kyle Wyman skidded on a rainy track, scraping the part. Because the part sustained the damage instead of the assembly, Kyle was back up on the bike and ended up winning the second race.
The second part had some similar characteristics to the shift assembly cover. On the other side of the bike, the exhaust pipes are often an area of the bike prone to scraping the track on tight turns. One of the most effective ways to reduce time on the track is by increasing lean angle in turns. The current exhaust system prevented maximum lean angle.
The Harley team wanted to reconfigure it, making it narrower and thus closer to the bike. This time they used 3D printing, leveraging Protolabs’ direct metal laser sintering (DMLS) service. They first printed a prototyped part with Stainless Steel 316L to identify an organic, flowing part that was less bulky, reducing the chances of scrapes. With a dialed-in design, the team printed the final part in titanium for installation on the race bike to reduce weight while maintaining durability. It was an ideal opportunity to use large-format DMLS, which reduced the time to produce the part as compared to processes such as casting.
None of this would have been possible without the advantages offered by digital manufacturing, which speeds up all aspects of moving from prototyping to production and end-use parts. In today’s economy, getting parts quickly is crucial to staying competitive.
