A normal sneaker until you don't want it to be.
SPEEDERS looks and feels like a premium low-top — knit upper, sculpted cushion, no loud branding. Double-tap the side and four micro-wheels drop from the sole. Now you lean to ride: weight forward to accelerate, back to brake, tilt to carve — like a hoverboard, on your feet. It's electric, and it charges two ways: every step you take harvests energy, or you rest them on a wireless pad. Walk to charge. Lean to glide.
The full parts list.
Hit Parts on the model to see these called out in 3D. Below is everything in the build — the shoe you see, and the systems inside that make it actually move and charge.
What you see
- Knit upperEngineered 3D-knit — breathable, sock-like flex.
- Toe capReinforced abrasion guard at the front.
- Tongue + lacesLocks the midfoot (or laceless sock version).
- Ankle collarMemory-foam padded opening.
- Heel counterStiff cup that holds your heel in place.
- Midsole + carbon plateDual-density foam over a springy carbon plate — the structural spine and wheel mount.
- OutsoleRubber tread for normal walking grip.
- Light-railSide glow strip — battery colour, turns red as a brake light.
- Drive wheels ×4~60 mm hub-motor wheels that deploy from the sole.
- Tap zoneCapacitive pad — double-tap to deploy / retract.
- Kinetic charge nodeHeel indicator that pulses as you harvest power.
Inside — what makes it work
- Kinetic harvester platesSpring-loaded heel + forefoot plates compress ~2–6 mm per step and drive a micro-generator. (Walk to charge.)
- Hub motors ×4Brushless motors built right into the wheels.
- Deploy mechanismServo swing-arms + locks that drop and lift the wheels onto a load path into the carbon plate.
- Battery + BMSLi-poly pack in the arch with a protection / management circuit.
- Wireless charging coilQi-pad charging — no cable, no port.
- IMU (accel + gyro)Reads your lean about 1000× a second.
- MCU + BluetoothThe brain of each shoe; left and right talk to split power.
- Motor drivers (ESC)Turn lean angle into smooth, speed-governed throttle.
- Safety sensorsWheel encoders + stair / curb / standstill detection for auto-retract.
Honest verdict from the build doc: ~0.9–1.4 kg per shoe (2–4× a normal sneaker), ~6–12 km of pure gliding per charge. It's a concept design brief, not certified drawings — a real maker still has to prototype and safety-test it (battery, deploy-lock fatigue, brake distance, stability).
Honest engineering check
The dream is solid and pieces of it exist today — but a few specs are aspirational, not shipping. No sugarcoating:
- Kinetic charging is real but small. Heel-strike harvesters make milliwatts-to-a-few-watts — enough to extend range and run the lights/sensors, not to fully power the motors. Walking helps; it won't replace the charger.
- Battery vs. weight is the hard tradeoff. More range means a heavier shoe. Real range on a shoe-sized battery is modest, which is why regen braking + kinetic top-up matter.
- Stability on small wheels is the real engineering challenge — a wider wheelbase plus good IMU control software is what makes lean-steering safe.
- How you'd actually prototype it: off-the-shelf hub-motor wheels + an ESP32 + an IMU + a small LiPo, get lean-steer working on a fixed skate platform first, then shrink it into a sole. Kinetic harvester is a v2 add-on.