Clean, Sustainable Mobility

Curtiss encourages first principle originalist thinking – the process of escaping the rabbit holes of design. The history of design and innovation is littered with dead ends, some of which have gained too much traction and been accepted as the de facto solutions despite better ideas being conceived along the way. By examining a problem from a fresh perspective without remaining beholden to existing solutions it is possible to create better designs; sometimes great breakthroughs can be achieved by revisiting old ideas that didn’t get their due. Simply asking “why” something is the way it is can reveal elegant new ways to reach your goal.

Internal combustion motorcycles are a rabbit hole in themselves, filled with compromises brought on by the many needs of the complex system that is gasoline power. Taking the basic elements of an electric powertrain and designing a motorcycle around its advantages, rather than trying to convert a gasoline motorcycle to electric power, is how we came to create Curtiss One.

The core of Curtiss One is the Curtiss Centered Power Axis, our proprietary solution for taking advantage of the packaging advantages of electric power. The Curtiss 217 axial flux motor, itself a remarkable feat of power density in a small package, is centered in the chassis along the vertical and horizontal axes. A hardened steel driveshaft passes power directly from the hub of the motor through the front swingarm pivot to the final drive pulley, for concentric belt geometry and an absolute minimum of parts to transmit power to the rear wheel. Belt geometry and tension thus remains constant through the suspension travel, and power is transmitted without shunt or intermediate devices – no clutch, no gearbox, no jackshafts, no bevel drives or turns in the power path. It is the most direct connection possible between your wrist and the motor’s torque.

The chassis of Curtiss One employs our proven Triple Load Path monocoque frame, the simplest, slimmest and strongest way to build a motorcycle. Two flat milled-from-billet 7075 aluminum plates form the chassis of Curtiss One, sandwiching the steering head, motor and Power Pak battery casing between the plates for a fatigue-free, flex-free structure that can easily be adapted to future models. Additional torsional strength can easily be added by inserting bulkheads between the plates, a layout inspired by aircraft wing and fuselage design. The space between the plates serves as a chamber to contain the wiring, plumbing and electronics of the powertrain, hiding unsightly ancillary components from view while allowing easy access to the systems.

Curtiss’ Power Pak represents the first application of a full-immersion liquid-cooled battery in an electric motorcycle. The 399 volt battery is arranged in a radial pattern, creating a cylindrical module that is inserted into the Power Pak casing and submerged in a non-conductive dielectric coolant. This finned aluminum casing serves as a the radiator for the Curtiss power train, with coolant circulated through the motor and inverter from the Power Pak via a small electric pump hidden inside the case. Power Pak is safer, more efficient and was designed from the ground up to be integrated into the Curtiss One – the casing serves as a structural element of the monocoque, and is integrated into the One’s design in a way an off-the-shelf power brick never could be.

The Curtiss 217 axial flux electric motor is the most power dense power plant ever fitted to a motorcycle. The 217 is 12 inches across and 4 inches wide, and weighs a mere 62 pounds. This unit is capable of peak outputs of 217 hp and 272 lb-ft of torque at 700 volts; in the One, we limit power to peaks of 120 hp and 147 lb-ft at 399 volts. Think of this as the hand-built Italian V-12 of electric motors, in a market where most electric powerplants are off-the-shelf forklift motors. As battery technology improves it is merely a matter of altering programming to unlock more of the potential power – but 147 lb-ft peaking from zero RPM is more than adequate in a motorcycle that weighs a mere 425 pounds, ready to ride. There has never been a gasoline engine that produces this kind of liquid-smooth power in a package this compact and light, while offering virtually maintenance-free operation, impeccable reliability, and silent operation without vibration or excess heat.

Curtiss One employs future proof design that ensures your motorcycle will never be rendered obsolete by the progress of EV technology. Modular construction allows for easy upgrades to the hardware as battery and motor technologies evolve, and over-the-air programming ensures your One will always be kept up-to-date with the latest software. This is in addition to our use of zero-compromise materials, components and craftsmanship in every Curtiss motorcycle that ensures the highest quality and the longest service for all our products. Curtiss motorcycles are built to last forever, heirloom quality works of art that can be ridden every day and handed down to the next generation.

Art to be Seen On
Curtiss One Design, Pt. 3: Ergonomics