- n. an urban street person



Personal Transport Vehicle

The initial idea was the authors vision of fun, portable and simple vehicle which developed into a project of electric personal commuter. The most important requirement during design phase and also the most demanding to follow, was simplicity of the vehicle itself and all of its components but without negative impact on functionality, robustness and reliability.

The second requirement was to include great fun while operating, so the flight-like tilting at turns and some other solutions borrowed from aviation were utilized for that particular purpose.

Other important features that came up during the project development phase were the ability to fold as well as customization according to user aspiration.


To create the vehicle for single person transport, primarily for use within urban city centers, that is also able to travel short to medium distance, does not need to be registered and is foldable for transport.

Safe & Secure

Basic construction to be made of cheap and widely available materials, eco friendly or recycled in the way that the construction and its parts are completely recyclable or easily repaired and that the production process is simple and does not impact the health of persons involved.


To use an ecofriendly, off-the-shelf solution for power motor that uses ethanol, compressed air, electricity or some other green energy power.

Introduce innovative, affordable, easy to use solution to a growing segment of personal vehicles.

Final solution is the tricycle in delta configuration (one front and two aft wheels), with the optional configuration change to tadpole in the way that two wheels are in the front and one rear wheel. Front wheel is electrically driven by integrated hub motor and is connected to a chassis while the aft wheels are steerable and connected to swinging arms which are then connected to chassis.

Upper part of the control mechanism is also connected to chassis while the lower consists of two symmetric systems and each one is located on its accompanied swinging arm. The main part of  each lower control systems is combiner which defines the setup of the vehicle that user can easily replace with another one with different setup to customize the steering, according to their aspiration.

Driving is performed in standup position, and can be done by using only one hand because all controls are located on the steering column.  Speed is controlled by the thumb and depending on the mode selected, steering is performed by tilting the vehicle left or right (like flying or skiing) or by moving the control column while the vehicle is in fixed mode.

The steering mode selector is located on the control column and is operated by twisting the certain part of the handle grip. Tilting mode is more appropriate for driving at higher speeds where driver during turns anyway has to lean to compensate for the centrifugal force, while at the same time gyroscopic effect from the spinning wheels that is more significant at higher speed helps stabilize the vehicle.

At lower speed (speed approximate to man pace) there is no more significant gyro effect nor centrifugal force so tilting mode becomes useless and selecting the fixed mode provides more appropriate way of control – the driver stands steadily and only moves the control column in the direction of a turn.

By folding the vehicle it “shrinks” to a dimension of a mid-size suitcase so it becomes transportable within a minute or two.

Prototype was built by the use of only very basic hobby tools at inappropriate place and with limited budget so it lacks some technical solutions and some are realized in a very rough way. The purpose of the prototype was to demonstrate the functionality and to present the approximate design.

Frame consists of few major parts that are mostly made of cheap square/rectangular tubes by welding while the cowlings are of epoxy and fiberglass fabric modeled over the styrofoam core.

Prototype is driven by the off-the-shelf E-bike kit by Golden Motor which is certified for use in EU countries.  Motor is brushless type, high efficiency electric motor that performs 30 km with a single charge. Compared to a small city car consumption of 5l/100km, this vehicle is at least 10 times more efficient because single charging of batteries costs less than 0.2€


Technical data

Prototype vehicle


105 cm
135 cm
(without control column):
60 cm
65 cm
Weight:38.8 kg
(without batteries):
26.5 kg
Measures when folded LxHxW:72x60x30 cm
Front wheel diameter:508 mm (20")
Rear wheels diameter:200 mm (8")

Drive: electric motor

Manufacturer:Golden Motor
Model:Smart Pie
200 -400 W
24 - 48 V
integral controller
cruise control
regerative breaking

Batteries: 48 V / 9 Ah

12.3 kg

Range & Max Speed

Range with single charge:
30 km
Max speed:
28 km/h *
* varies with driver weight, controller setup, voltage and type of battery



Vladimir Bošnjak


Phone: +385 91 446 4718

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