The Switchblade – A Low-Cost Gravity Self-Righting Leaning Vehicle

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The enclosed motorcycle (“cabin cycle”) marries the efficiency of the motorcycle and the weather/crash protection of a car. Such a vehicle can fulfill all the roles motorcycles currently fill – from “fun” machines to police patrol – and many more with the all-weather capability and crash protection.

The Peraves Monotracer and the Carver One are the current production state of the art.

However, both vehicles are very expensive – costing $100,000 and $80,000 respectively – since both need sophisticated computerized powered stability and lean-control systems in place of the now enclosed motorcyclist’s legs – normally used to stabilize the open motorcycle.

While similar to the Carver in layout (with separate passenger and powertrain “pods”), the proposed “Switchblade” (SB) will cost much less – with a price point of rmally cause it to fall over. The Carver uses its expensive powered stability system to keep it upright.

However, if one realizes that as a vehicle leans over, its CG loses vertical height also – and potential energy. Therefore, if the CG height loss during the lean is countered by an equal and opposite lifting of the CG, a net zero energy gain means the vehicle does not fall over.

This is the key to the SB’s gravity self righting ability. When the SB leans over along the fore-aft (longitudinal) axis, a cam-actuated “jacking hinge” causes it to simultaneously “jack-knife” on the side-to-side (lateral) axis between the passenger and powertrain pods – cancelling any CG height energy loss (“H”).

And with constant CG height, the SB will not fall over due to the resulting zero energy balance – regardless of lean angle.

Furthermore, the driver via the foot pedals - can add additional CG height – and potential energy – that is used to return the SB from a lean to an upright position (“E”).

The result is simple mechanically and most importantly – low cost. Slide [3] shows the working details of the jack hinge mechanism and what Pod they are attached to – Passenger (PASS) or Power Plant (POW).

Finally, unlike a spring-return system, the gravity jack hinge stability system is weight insensitive and will self-right no matter the weight.


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  • Name:
    James Lin
  • Type of entry:
  • Software used for this entry:
    Autodesk Inventor, Microsoft Office
  • Patent status: