Kick Scooter Product

Overview

A kick scooter is the simplest practical wheeled commuter: a low platform on two wheels, pushed by foot and steered by a handlebar. The adult version described here — large 200 mm wheels, telescoping stem, one-lever fold — descends from the aluminium micro-scooters of the late 1990s, and is built to EN 14619, which load-tests deck, stem, and fold for a 100 kg rider. There is no drivetrain at all; everything in the bill of materials exists to roll efficiently, fold small, and stop on demand.

Deck and rolling gear

The Deck is the structural backbone. Its core is the Deck Extrusion, a hollow multi-cell 6061-T6 aluminium profile — extrusion gives a stiff, light beam at very low part cost, and the internal webs put material where bending stress is highest. A die-cast Head Tube Casting closes the front and sets the steering axis at about 78 degrees, steep enough for agile low-speed steering; the Rear Dropout plates close the rear. Grip Tape on top keeps wet shoes planted, since the kicking foot lands on the deck edge hundreds of times per kilometre.

Both ends roll on the same Polyurethane Wheel: a 200 × 40 mm wheel with an 85A-durometer polyurethane tire cast onto a spoked core, spinning on two 608-size Ball Bearing cartridges over the Axle Kit. Wheel diameter is the main comfort variable on a vehicle with no suspension — 200 mm rolls over expansion joints and cobbles that stop a 100 mm toy-scooter wheel dead. Durometer is the efficiency/grip trade: 85A is hard enough for low rolling resistance yet compliant enough not to skate on smooth stone. The front wheel is held by the welded Fork, whose steerer turns in the Headset — the same threadless angular-contact bearing arrangement as a bicycle, preloaded by the Top Cap against the Compression Ring before the stem clamps.

Braking

Stopping is the rear Fender Brake: a spring-loaded stamped-steel fender hinged over the rear tire. Stepping back on it with a heel presses the fender onto the tire crown; deceleration is proportional to foot pressure, and the Brake Return Spring lifts it clear on release. It is a deliberately crude brake — friction directly on polyurethane fades when wet and flat-spots the tire under panic stops — but it has no cable to stretch, no pad to adjust, and nothing to fail silently. Riders supplement it by dragging the kicking foot. Faster commuter variants add a bar-lever drum brake, but the EN 14619 baseline is the stomp fender.

Folding and adjustment

The fold is the feature that makes the scooter a last-mile vehicle rather than a toy. The Folding Mechanism sits where stem meets deck: cast Hinge Body halves rotate about the Hinge Pin, and the over-centre Lock Lever wedges the hardened Lock Tooth into the riding detent. The engineering requirement is zero perceptible play when locked — any slop at the hinge is amplified a metre up at the grips — while still releasing with one hand. Folded, the stem lies along the deck and the package is about 870 mm long and 4.5 kg, light enough to carry up stairs or onto a train.

The Folding Stem telescopes between roughly 750 and 1,050 mm of grip height: the Inner Stem Tube slides in the Outer Stem Tube, indexed by the spring Height Index Pin and clamped by the cam-lever Height Clamp. Pin plus clamp is a redundancy requirement — the clamp alone could slip under a rider's weight on a bump. Up top, the Handlebar is a T-bar whose Grips fold down on push-button Grip Hinges so the folded width shrinks to the stem diameter; a thumb Bell covers the pedestrian-warning requirement many cities impose on footpath vehicles.

Use

Propulsion economics favour the scooter over walking by roughly a factor of two: a rider cruises at 10–15 km/h with kick cadences near one per two seconds, coasting between kicks on low-resistance bearings. The limits are equally clear — no suspension, small contact patches, and a brake that depends on dry rubber — which is why the format thrives on smooth urban pavement and ends at the kerb.