Model 1

2025

Solid

The Solid® Model 1 combines the ease and practicality of a moped with the light-weight convenience of an e-bike. It’s an entirely new class of vehicle that’s truly more convenient, efficient, and fun. This case study delves into the design and development journey that brought this innovative vehicle to life.

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Foundations

Before diving into sketches and prototypes, we needed a clear vision of what Model 1 should be. That meant digging into the market, defining key features, and understanding how people actually want to use their urban vehicles. Mood boards, competitor research, and a solid list of must-haves helped shape the design from the start.

Design Language

We aimed for a design that felt familiar yet fresh—something approachable and easy to use while still standing out. The images and descriptors we explored early on helped set the tone for both aesthetics and functionality.

Core Features

We started with a strong focus on theft protection, but after real-world testing and user feedback, we shifted priorities. The final design balances security with ease of use, performance, utility, and comfort.

Competitive Insights

Sizing up the competition gave us a benchmark for weight, size, and pricing, but since Model 1 was carving out its own category, we had to think beyond direct comparisons. The goal was to create something that felt natural to ride, even for people who’d never used an e-bike or moped before.

Sketching, Modeling, Iterating

The early design phase was all about experimenting with different forms and structures—step-through vs. top tube, battery placement, and how to integrate suspension while keeping the weight down. The process moved from quick digital sketches to VR modeling and then into refined CAD work as we locked in the details.

Modular top tube

Rapid sketches to explore silhouettes and overall form

Solidworks underlay

CAD development for refining structure and mechanics

prototypes

We built five working prototypes to put our ideas to the test. These helped us fine-tune everything from frame geometry to drivetrain performance.

Welded steel frames
Drivetrain Testing
Load testing
Ergonomics Testing
User Testing in SF
Utility exploration
Bike Lane Testing

What we learned

Geometry & Ergo

One of the biggest takeaways was how much geometry impacts ride experience. We designed the prototypes with a modular setup—adjusting wheelbase, rider height, foot placement, and steering response on the fly. The result? A ride that felt stable yet nimble.

One challenge we uncovered: the off-the-shelf battery we started with affected seat ergonomics, making longer rides less comfortable. That led to a redesign focused on better integration.

Power & Performance

We wanted Model 1 to be fun, responsive, and easy to ride. A dual-wheel-drive setup gave it incredible power and torque without adding unnecessary complexity. The results were immediately apparent – this thing rips. We even found ourselves having to pull the power back a notch.

Based on our previous experience at Boosted, we also knew that regenerative braking is a big deal and something intangible that keeps people coming back for more. We tested these prototypes with throttles from the Boosted Rev scooter, which was a great start.

Cargo & Accessories

Hauling gear is a no-brainer for us. With the power our drivetrain delivers, adding cargo capacity only makes the bike more versatile and appealing. We started exploring a modular mounting system inspired by military MOLLE rails, allowing riders to customize their setup based on their needs.

During testing, we realized that the bench seat and rear rack had some limitations—especially with the looptail frame design. Passenger seating felt a bit compromised

Visual Appeal

Our prototype design was definitely unique—it turned heads and sparked conversations. But due to limitations with locally available bending dies, the final form didn’t have the balance we originally envisioned. While some people found the look refreshing, others felt it didn’t quite capture the fast and fun nature of the bike. We took that feedback seriously and used it to guide future development.

One thing we did get right? It stood out while still feeling friendly and inviting. That welcoming character was something we knew we wanted to preserve as we refined the design.

The bigger question:

Who is this bike really for?

To find out, we built and tested three designs – each with its own personality.

Looptail

Classic and relaxed, this concept focused on implementing feedback on our initial prototype. Raising the chainstay and bottom bracket and increasing the slope of the downtube made a more sporty profile. We also moved the battery to a lower location, which allowed the seat to be more narrow while also lowering the center of gravity and visual mass.

Hi-Step

Approachable and stout, this concept focused on increasing utility, simplifying manufacturing, and feeling familiar to everyday riders. With a more “standard” step-thru silhouette and larger rear rack, it blends into the bike lane. It also borrows a bit of retro Honda Trail vibes – highlighting its rugged capability.

Sporty and streamlined, this concept’s near-vertical “seat tube” gives it a primed-to-strike stance, while the joint between the seat tube, top tube, and seat create a sophisticated focal point. With a removable rear rack, it feels a bit more like a sports car with major cargo capacity.

Pit Vert

User Feedback

By evaluating all three concepts side by side, we gathered direct feedback on what worked, what didn’t, and what truly mattered to riders. Outside perspectives helped us see beyond our own biases, revealing key insights about comfort, handling, and practicality. These conversations guided our decisions, ensuring that the final design wasn’t just something we thought was great—but something real users actually wanted.

The Final Direction

After gathering feedback, the Hi-Step emerged as the clear winner. Its approachable yet rugged design balanced utility, manufacturability, and everyday ease. With a familiar step-thru silhouette, a large rear rack, and a hint of retro DNA, it feels both practical and adventurous.

The Model 1 is a bold yet familiar step toward the future. Its rugged and approachable nature invites users to experience their world in a new way.

Photos by Chivalry Creative

Logo design by Levi Price

Develoment

Take a look behind the scenes to see how we continued our development for production.

Frame

With a tight rear triangle and a high chainstay, the frame is built for go-anywhere capability – a nod to the classics. It’s oversized, hydroformed downtube acts as a strong backbone, both visually and structurally. Internal routing and bolt-on CMF contrast points keep the silhouette clean and streamlined while chunky tube profiles help the bike feel… solid.

Frame post heat treating. Steel fixtures hold critical dimensions in place during the process. Notice the large frame openings and the motor cable routing in the right chainstay.

1/4 scale print to better evaluate proportions and fit

Clear frame print to evaluate cable routing and as a fit check for all major components.

Machined parts for prototype frames. As production parts, the rear dropouts would be forged, the peg mount extruded, and the small parts turned or forged depending on quantities.

Main frame tube is extruded, hydroformed, and laser cut. Tooling was made for this part since there's no other way to prototype it.

Peg Mount interface with frame before welding.

We initially planned on putting both motor controllers in the rear of the seat tube, but assembly proved difficult, so one controller was moved to the downtube instead.

Racks

We maximized utility by creating extra storage locations and integrating a modular mounting architecture throughout.

Rear Rack

The workhorse. Built to carry heavy loads up to 150kg, it features pannier rails, a thick aluminum mounting plate, and our molle attachment system, so you can hook, strap, or bolt gear with ease.

Center Rack

Surprisingly useful. Perfect for precious cargo like a larger child, takeout, or anything you want to keep close. Since there are no pedals, you can use your knees to help stabilize items.

Front Rack

Designed to accommodate oversized loads like a pizza box while keeping a raised perimeter to secure smaller items. You can bungee almost anything to it.

Testing the width limits of the center rack

Testing extra-large items on the rear rack

Larger kids fit great on the center rack with just a pad

Lock storage. Voile straps work perfectly

Custom aluminum milk crates with our molle pattern throughout

Battery

The battery pack nests into the frame, secured by two structural brackets. After exploring multiple housing architectures and cell configurations, we landed on a 3-part clamshell design with the BMS and charge port mounted along the top of the cells for easy access. The high-power discharge port is located below the battery where it’s secure and protected.

Early concept for cell blocking and charge discharge port location

Secondary concept for discharge port location

Concept illustration for extruded profile with molded sides

Surface exploration for drafted 2-part clamshell design

Exploration for 3-part plastic construction

Exploration for 3-part construction with extruded aluminum center profile

Pegs

Designed for both rider and passenger comfort, the same pegs can mount to the front peg hanger or the rear dropouts for passenger use. They feature an anti-rotation mount and fold up for a slim bike profile. The peg hanger mounts securely to the bike frame and allows fore-aft fine tuning of the rider peg position.

M10 Bolt detail for mounting to peg with a single tool

Peg prototype from Taiwanese vendor showing oblong mating feature

Motor

Developing our own custom motor was key to getting the powertrain to perform exactly as we needed. A major innovation was integrating the torque arm directly into the axle, which enabled us to use a suspended front fork while making wheel removal much easier compared to bolt-on torque arms.

3D print of our custom axle to check fit with stator

Machined axle prototype with integrated torque arm interface

First article from our Taiwanese vendor showing ID surfaces, CMF, and full integration

Fork

Mounting a front motor on a suspension fork isn’t easy, but this challenge led us to develop an inverted moto-style fork. This minimized tooling costs while allowing us to smoothly integrate our torque-arm axle for a clean and functional solution.

Designing the fender mounting strategy and integration with mud guards

Initial exploration of cable routing for the large front motor cable

3D printed prototype with zip-tied Higo motor connector

Throttle

We knew from our previous work at Boosted that throttle control would make or break the rider experience – especially with regenerative braking being so important. Our design provides high-fidelity control, ensuring smooth acceleration and braking at the push and pull of a thumb. The latest iteration feels locked-in and confident, preventing jerky movements when riding over rough terrain.

Dished profile tested to fit thumbs both big and small

Exploring different throws and knurling patterns. Something like this take a lot of prototyping and A:B testing

Near-final texture. The large slots provide a macro grip, while the fine knurl sticks to your skin.

Early concept for a user interface with turn signals and horn.

Display

We kept the UI simple and intuitive, so riders can focus on the road. But beneath the clean interface, it packs GPS and cellular connection for OTA updates and tracking precision to the nearest meter. The display also enables quick ride mode toggling, letting users adjust speed settings on the fly.

Display board with GPS, LTE, & Bluetooth

Early exploration of a turn signal interface

Saddle

Since our bike blends elements of a bike and a moped, we wanted a saddle that does the same. The goal was to combine a familiar silhouette with the comfort of a larger saddle. Without the need for pedaling, we could increase support and reduce pressure on the sit bones. After multiple form studies and functional prototypes, we dialed in just the right balance of shape and softness.