The MotoCzysz E1pc

Monday, June 28th, 2010

Former motorcycle racer and architect Michael Czysz — pronounced “sizz” — founded MotoCzysz to develop the world’s most advanced electric motorcycle, the E1pc:

This is the 2010 MotoCzysz E1pc, a race bike built by a tiny Oregonian company focused on pushing the limits of electric performance to the absolute max. It packs 10 times the battery capacity of a Toyota Prius and 2.5 times the torque of a Ducati 1198 into a package that looks like something out of a 24th-century Thunderdome.

The writer, Wes Siler, had me until Thunderdome. The gladiatorial arena in the post-apocalyptic settlement of Bartertown — in the third Mad Max movie — is decidedly low tech.

His later simile works better:

The E1pc looks like an X-Wing crossed with an iPod to the other electric racer’s cobbled-together adaptations of existing internal combustion engine bikes.

Unlike last year’s model, which used off-the-shelf parts and fried its electronic control unit after the first lap of the Isle of Man TT, this year’s model is almost completely custom designed:

“A bike has a relationship with the rider and a balance that is way beyond cars and computers, so you can’t just randomly shove stuff around and hope it works,” describes Czysz. “You have to work around the batteries, they’re they largest component, the heaviest component and the most important component.”

On the 2010 E1pc the batteries are huge, visually dominating the bike and occupying the space traditionally reserved for an internal combustion engine. There are 10 individual lithium polymer cells that each weigh 19.5 Lbs and were hand-assembled by a company that typically builds batteries for NASA. The level of integration here hints at the kind of work that’s gone into the rest of the bike. There are no wires connecting the batteries to the bike or any exposed terminals. Instead, posts on the batteries lock into receivers on the bike’s frame, at once making the electrical connection and supporting the batteries’ weight. The proprietary internal arrangement is secret, so we can’t show you a picture of it, but it allows the batteries to be swapped out in just a couple of seconds.

That ability is crucial. The electric motor is powerful enough to chew through the 12.5 kWh of on-board power in just 40 miles under race conditions (in comparison, the 2010 Toyota Prius’s battery pack holds just 1.3 kWh and can travel only a single mile in full-electric mode). Quick-swap batteries allow the team to run road tests without waiting four hours between charges and, more importantly, removable batteries bring huge safety benefits. The E1pc is running close to the maximum allowable 500 volts, enough power to turn a wrench into molten metal in a flash of white light or split a mechanic’s hand in half (it’s already done the former). The ability to remove that power source from the bike before working on it renders the machine safe from accidental electric shocks. This level of safety and convenience have clear applications in mainstream electric consumer vehicles — don’t expect Czysz’s patents to stay on one-off race bikes.

But the custom-engineered, oil-cooled electric motor that sucks up those batteries’ juice may be the single most important individual component driving the E1pc’s exceptional performance; while most electric bikes repurpose electric motors built for forklifts or high-power drills, Czysz’s motor is the first to be developed from the ground up to win races.

The DC internal permanent magnet motor, which Czysz calls “D1g1tal Dr1ve,” is small enough to hide within the swingarm beneath the rear shock. The oil-cooled motor makes more power and torque than all three air-cooled motors in last year’s E1pc combined, while being smaller than one of them individually. And crucially, it develops its 100 HP and 250 Lb-Ft of torque continuously. Air-cooled electric motors, on the other hand, quote peak figures which they’re only able to reach for a very brief period of time due to the rapid buildup of immense heat. Sometimes, they can only reach peak power for a fraction of a second. The MotoCzysz can always make that 100 HP — as long as the batteries hold out, that is. The oil-cooling is key here, allowing the motor to exponentially shrink in size and weight for its output level; air-cooled motors are huge, so their large metal components can soak up the heat.

With limited energy capacity and therefore limited power, a high-speed racing bike has to efficiently cut through the air:

“Ninety percent of a vehicle’s power is used simply to move the wind,” says Czysz, pointing out how aerodynamics play an even more important roll on electric vehicles than conventionally-powered ones (exhibit A: the Prius’s odd stub nose and compressed rump). Czysz has radically reduced the frontal area of this year’s bike — eyeballing the two next to each other, 2010 looks a third slimmer than 2009 — but it’s the wind’s exit that’s more important than its entrance.
So the challenge for a motorcycle aerodynamicist is to recombine the airflow behind the bike so it’s not sucked backwards as much as it is to split air cleanly around the front. Czysz also created ducts through the E1pc’s frame that suck air from the high-pressure area at the front through to the area beneath the seat, breaking up the low pressure. Gulfstream-jet-style winglets on the fairing whirl turbulence into these ducts just as the pull air rapidly through the motor and controller-cooling radiators.

The other extreme limiting factor to motorcycle aerodynamics is the big leather sack of human sitting on top, spoiling the airflow. Czysz has addressed this too, with perhaps the defining visual element of the 2010 E1pc. Turning to time trial bicycle racing for inspiration, he created a second riding position that the racer will move into on straights. By sliding their butt off the main seat and onto what’s basically a modified pillion pad at the extreme rear, the rider adopts an incredibly low, flat-backed riding position that still gives them the ability to keep their feet on the foot pegs and hands on the handlebars; they can still fully control the bike in this position and even attack high speed corners by weighting the pegs and turning the bars.

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