T. Flex by Siavash Jafari Jozani

T. Flex


Siavash Jafari Jozani

San Francisco, USA

2020 & 2019 Michelin Challenge Design Finalist


THE LEANING SPORTS WHEELCHAIR | T.FLEX is an Adaptive Extreme Sports Wheelchair that aims to redefine the pleasure of having an active lifestyle with an enjoyable machine for individuals with limited lower-body mobility. This bike incorporates innovative steering and a flexible structure to realize ultimate freedom.

The concrete structure of traditional wheelchairs is limited to only two dimensions and one axis on our multi-dimensional planet. It fails to offer the fluidity and freedom the user needs to experience their adventure to its full extent. Traditional wheelchairs are designed to be steady and balanced. This stability, along with the complications of relying only on arms for steering and generating power, has turned wheelchairs into an unbending add-on to the human body that refuses to unite with it.

Unlike the rigid and solid characteristics of traditional sports wheelchairs, T.FLEX allows for the rider and the bike to become one, just like any other sports vehicle. T.FLEX Leaning Bike introduces freedom of movement and flexibility to adaptive sports. It aims to add excitement and adrenaline rush to the ride.

The riding position is highly customizable on this vehicle to meet the needs of individuals with diverse body characteristics as listed below:

Paraplegic: legs can be retracted under the body. A weight-bearing pad prevents the body weight from pressing the legs if the athlete is comfortable bending their legs beneath their

Above-knee amputee: The athlete sits on a custom-made pad that fills the seat’s extra depth and keeps the body steady and at a preferred height. Modular adjustable seat belts provide a stable and comfortable ride.

Below-knee amputee: The athlete rests their limb on a custom-made socket printed as part of the 3D printed structure.

Other disabilities: A footrest is printed with the Alloy structure to keep the legs in a comfortable position and make the ride accessible to all ability levels. Since the athlete’s hands are needed for generating power and braking, the steering interaction is performed by leaning sideways. for example, The bike turns right when the athlete leans to the right, and it goes straight when the athlete keeps the balance even.

A Four-Bar Linkage couples the 3D printed steering structure to the seat and the chassis. This mechanism transforms the body’s side way movements to turn the wheels. The intuitive nature of this steering function creates a seamless interaction between the rider and the bike.

The acceleration mechanism is inspired by the “Seated Cable Row” gym exercise. Rowing levers located on each side of the rider’s seat are pulled and pushed in an ergonomically designed position to accelerate the bike. The lever’s layout is set to take full advantage of the athlete’s power and maximize the human body’s efficiency.

The 3D printed alloy structure responsible for the steering function is designed and printed with customized footrests and accessories to accommodate each individual adequately.


Siavash is a Designer based in San Francisco with a passion for creating the future of mobility. Having his bachelor’s degree in Industrial Design and experiencing the industry since 2012, he has practiced design in research and observation tools, creative problem-solving methods, concept generation, and concept evaluation. Siavash has achieved outstanding accomplishments in the Transportation Design field, including the Finalist title of 2020 and 2019 Michelin Challenge Design, Overall-Winner title of the Car Design News Interior Motives Awards 2012, and Most Innovative Design title of the Launch Forth Mobility Design Challenge 2018.

To further explore his designs, you may visit www.siavash-design.com.