How Inspiration from a Rifle Mechanism Makes Our Transmission Bulletproof
Precision where it counts, clearance everywhere else.
I’ve always believed that the best innovations come from elegantly simple ideas. At Inmotive, our approach to transmission engineering isn’t about getting around complexity, it’s about stripping it away until we’re left with designs that feel almost inevitable in their simplicity.
This philosophy isn’t abstract; it’s rooted in practical, time-tested insights from across industries and history. For me, inspiration came from reading about Eugene Stoner’s approach to design, problem solving, and the innovative engineering that resulted. While Eugene Stoner is best known for firearms design, I’ve drawn from Stoner’s reductive ethos to inform our approach, applying those same principles in our efficiency-focused mobility domain. We’re bringing similar functional clarity to transmission shifting and have been for the last 10 years. It is particularly visible in our latest Gen 5 Ingear design released in 2025 and our first of its kind two-wheel eScooter transmission. We’re eager to share how this approach can benefit the application of our transmission shift technology to your products.
Learning from Eugene Stoner and Firearm Engineering
Stoner’s breakthrough was to isolate the tight‑tolerance locking lugs that hold a rifle bolt from explosive pressure and violent motion of the bolt carrier that cycles through heat, fouling, and grit. Precision was concentrated only where it mattered; everywhere else, more clearance boosted reliability and cut cost.
We adopted a similar principle in what we call the “floating segment” mechanism within our sprocket systems. The segment‑delivery carriage is free to live with stamping variation; once a segment reaches the disks, chamfers guide it onto precision faces that ensure position under load. The result is a mechanism that assembles without finished machining, shrugs off contamination, and delivers consistent efficiency above 98 % even at 350 N·m continuous torque.
Borrowing the principles of simultaneously integrating part functions while separating and isolating component requirements lets Ingear handle hundreds of thousands of shift events without drift. Innovating upon that firearms-inspired mindset turns high-cycle rapid-actuation into predictable, repeatable reliability for EV drivetrains.
The Approach Benefits Manufacturing, Reliability, and Simplicity
The most effective designs are those explicitly created with ease of production in mind, utilizing common materials and inexpensive serialized manufacturing processes. The goal is to make the necessary design features net shape with as little post processing work as possible.
Eugene Stoner’s methodology also advises the deliberate avoidance of unnecessary precision. Precision can be an enemy of reliability and cost—excessively tight tolerances and overly precise parts are more prone to issues such as fouling, wear, and eventual failure. To mitigate this in high volume production adds substantial cost. Instead, our design leans on the concentrated precision in specific areas to ensure greater reliability and lower cost. By relaxing tolerances where the physics allow—and stress-testing to confirm the limits—we strike the best balance between manufacturability and lifelong reliability. Decades of high-volume automotive-manufacturing experience informed this latest iteration; our cross-disciplinary team translated initial inspiration into the 90 % “perspiration” required to meet modern production targets.
Another key aspect of our design philosophy is component clarity. We break it down to the fundamentals so that none of the components are doing a job they shouldn’t be doing. Part-count reduction requires overloading multiple functions to parts, but delineating clearly means the actuator system actuates, the segment engages, and the double-disk pair carries load symmetrically. Every component in our systems is designed toward its primary function and overloaded carefully. This clear delineation of tasks ensures high performance, ease of assembly, and exceptional durability.
Shifting Simplicity: The Gen 5 Breakthrough
The transition from our Gen 4 to Gen 5 gear systems marked a significant breakthrough in simplicity and cost-efficiency. While the Gen 4 design met many of our initial performance objectives, the Gen 5 design perfectly exemplifies our commitment to simplicity and practical engineering. By significantly reducing complexity, we achieved lower manufacturing costs without sacrificing any performance objectives.
Gen 5 achieved substantially fewer parts (47% fewer, to be exact), each designed for markedly relaxed tolerances and material strength. This strategic choice led to profound improvements in our selection of manufacturing and quality assurance processes. The parts became easier to produce, with suppliers readily meeting our requirements without additional cost or difficulty. Assembly of the Gen 5 system was straightforward and efficient, reflecting no fitment issues and no rework even in the prototyping phase.
The results of this simplified approach were immediately apparent in real-world performance. Gen 5 systems consistently demonstrate improved reliability and superior durability. Additionally, we saw marked improvements in noise, vibration, and harshness (NVH) characteristics, factors crucial for user experience and overall component longevity. This design not only validated our core engineering philosophy but also enhanced our confidence in predicting long-term durability and consistent operational performance.
In essence, the Gen 5 breakthrough illustrates how thoughtful simplicity, applied rigorously to a system, leads directly to tangible enhancements across performance, reliability, and manufacturing efficiency.
Final Thoughts
By combining the principles of separation-of-function and removal of unnecessary precision with modern automotive processes, we’ve delivered the world’s most efficient EV drivetrain that meets the harshest duty cycles while staying friendly to mass production. By grounding our engineering approach in practical simplicity and learning from historical successes, we’ve delivered a transmission like our Gen 5 Ingear system that transform automotive capabilities while controlling costs.
But beyond showcasing our methods and results, we invite you to consider what these principles could mean for your own engineering challenges. If you’re seeking a partner who prioritizes efficient, robust, low cost and manufacturable solutions, we’re ready to collaborate. Reach out, and let’s explore together how the power of simplicity can shift your next EV breakthrough.
About Inmotive Inc.
Inmotive is a pioneering developer of ultra-efficient multi-speed powertrains for electric vehicles. The company’s flagship product, the Ingear™ transmission, delivers superior efficiency and performance for a wide range of EV applications. Committed to advancing sustainable mobility, Inmotive partners with leading manufacturers to redefine what’s possible in electric and alternative energy transportation.