Among his other unusual hobbies (he also builds sculptures featuring fire-spewing robots), 32-year-old Justin Gray makes custom electric motorcycles. To create his latest drag racer, the R144, Gray tore the motor and gasoline systems out of a 1999 Yamaha R1, a bike with a frame large enough to hold the extra parts he needed for the conversion. Since the gas engine had been an important structural element in the original bike, he built his own aluminum motor bracket to hold the modified bike together.
Forty-eight lithium-iron-phosphate batteries feed power into the motorcycle's controller, which determines the rate at which electricity travels to the motor. The result is 420 pounds of unusually quiet motorcycle, with 100 horses and a top speed of 150 mph.
Build an Electric Bike
Time: 10 Days
DC-to-DC Converter: Power-drawing accessories like the headlights don't need anywhere close to the amount of current emitted by the enormous battery pack. So Gray performed some surgery, bypassing the motorcycle's original charging circuit and modifying the wiring harness so it could accept a 12-volt signal from the converter. He also removed unneeded engine-control parts like the oil sensor and the gas gauge.
Battery Pack: Each of the 48 3.3-volt, 50-amp-hour cells weighs half as much as a lead-acid battery. Besides having a much smaller ecological footprint, the lithium-iron-phosphate cells are safe as well. "They don't have the high energy density of lithium-ion [batteries]," Gray explains. "But they also don't explode randomly."
Controller: Gray used a Curtis 1231- model controller, which is commonly paired with the motor in Porsche 914 electric vehicle conversions, to move the power to the motor. He has turned down the rate at which it throttles up, because the intense acceleration at its maximum rate of 550 amps is "a little scary" for the rider.
Motor: The 60-kilowatt series-type motor turns a chain connected to the rear wheel. In proportion to how hard the rider hits the throttle, the controller modulates the current delivered to the motor. Although the manufacturer says 144 is the maximum voltage the controller can handle, Gray pushes it well above that for higher performance.
Charger: The bike plugs into a charger via a port located just underneath where the gas tank had been. Designed to solve the challenge of powering up 48 separate batteries without damaging them by overcharging, the charger takes just four to six hours to juice up the bike, which can go 60 to 100 miles on a single charge.
Gray's isn't the only electric racer, turn the page to check out two more.
To design an environmentally responsible moped that could be used to make short deliveries, English TV host and engineer Jem Stansfield settled on air tanks as his power source. The carbon-fiber tanks—only about five pounds each because they were made for firefighters' breathing apparatuses—power two compressed-air motors, giving his low-revving vehicle a range of seven miles and a top speed of 20 mph.
The air compressor it uses requires juice from an outlet but can refill the tanks in seconds. Stansfield also replaced the back wheel of the original moped with a BMX wheel and, to increase its efficiency, added the hub gear system from a bicycle so it could run in a range of gears.
Time: 4 Days
The Dream Car
With a body that's a cross between ancient Egypt and the vehicle from Woody Allen's Sleeper, the 6,000-pound Dream Car 123 is not your run-of-the-mill electric vehicle. Inventor Greg Zanis, who had imagined building a pyramid-shaped car since he was a young boy, sits inside, enclosed behind bulletproof glass. The heavily reinforced base contains 80 lead-acid batteries that drive the four motors (one in each wheel). The current version of the Dream Car travels 240 miles at a top speed of 45 mph, after charging for 3.5 hours on only about $5 worth of electricity.
Time: 18 Months
Check out PopSci's complete coverage of the future of the environment at popsci.com/futurecity.
Man i have been waiting for this news a LOOOOOOOONG time now. I almost started to think it was not possible to make a electric motorbike. on what i see on this bike it still looks a bit chunky but i hope that will change in the future! if this technology is getting a bit more advanced i would like to convert my Yamaha XJ900S Diversion in to a Yamaha Electric Diversion!
Over 35 years ago I read about flywheel storage systems and was hooked on that idea for power vehicles; even the future spaceplane. To maintain the vacuum of the flywheel canisters, I would use a flywheel atop two motor/generators and one below them that would all be sealed. Either forced air or a liquid coolant would cool the motors without releasing the vacuum. If either rock quartz or one of my ultra-stressed materials is used for the flywheels and magnetic bands are used around the circumference of the flywheels and facing the bands inside the canisters, there might be a linear induction effect which may increase the storage potential.
I might use a hub-mounted motor in the center of the back wheel for instant power and maybe one for the front wheel for extra traction. If they are 100-horse pulsed injection motors, they may only require 70,000 watts each. If my flywheels can store 100 watt-hours of energy per cubic inch and I had a large stacked unit for the drive and a smaller stacked unit for the systems and the large unit contained 1500 cubic inches of flywheel material, the range for the bike might be 200 miles. For long-distant touring, I would use a "power trailer" that would have at least 5000 cubic inches of flywheel material and trunk space for luggage and other things. If the bike could cruise the highway at 70 mph and required only 60 horses from the motors, the range could be over 1000 miles. Since the bike would be an electric, it would be quiet enough for the rider to easily listen to a radio or CD player without having them blast away. With a canopy that could be attached to the bke, the vehicle could be ridden in all weather. Also, with the speed-activated roller kickstand, the rider won't have to put his feet on the ground until he wants to get off. The kickstand will extend automatically when the bike is traveling 5 mph or less and retract when the bike is traveling over 5 mph. .
Personally I am far more interested in the compressed air bike. That is exactly what I hope to build next summer.
Currently, I am in first year Mechancial Engineering at the University of Toronto.
I love the idea of an electric bike. I am going to build one out of an old mountain bike that has been collecting dust for about a year. I am going to use a 36 volt 1 kilowatt motor and a Kelly 100 amp controller from cloudelectric.com and a throttle and 3 12 volt 7 amp/hour batteries from evparts.com. I will use a 60 tooth sprocket at the engine and a 10 tooth sprocket at both wheels (both will be driven by the same motor). The motor has a rev limit of about 2500. With this gear ratio and rev limit i should be able to go about 70 (I know this because i have another mountain bike which i put a 50cc 26000 rpm gas engine on with the same gear ratio and it will go almost 80 mph(unsur of exact speed, no speedometer). This will cost me about 600 dollars but will be well worth the cost.
sorry about the error. I will be using 6 12 volt 12 amp/hour batteries which are the same dimensions and only 1 pound more.
Very nice specs on this electric conversion design. Terrific work. If you'd like to check out a production electric motorcycle without having to do the conversion work yourself, we've worked hard to bring our offering to market.
CEO Zero Motorcycles Inc.
. “They don’t have the high energy density of lithium-ion [batteries],” Gray explains. “But they also don’t explode randomly.....!!!!!!!!!!!???????????!!!!!!!!!!!! .....Boy, am I glad I read this article, I got those dahmn thangs all over the dahmn place! ...OHHHHHHHH MY GOD!!! They can just ..what ..explode like a ...what...
I ride a 2001 YZFR-1,...... Hmmm....
It's excelent to see more and more people converting vehicles to electric. I personaly just finished converting my 1988 for ranger into a 144 volt electric. I didn't have to money for Lithium ion batteries so I had to settle for 24 6-volt lead acid batteries, seeing as each one weighs around 66 pouns the truck is a tank. The range is around 100-115 miles on a full charge. It is the most bizzare thing sitting at a red light and having the car be dead silent. Ilove allof the looks i get from people crossing the street:)
ELECTRIC MOTORSPORT INC. of Oakland California comissioned Justin Gray to build the R-144 and as always he did an excelent job on the conversion. We whould also like to thank Jeff Hagan AFM rider #42 for supplying us one of his old R-1 race bikes for the build. Electric Motorsport sells EV parts and is also the manufacture of the first freeway capable production electric motorcycle.
It is our goal to provide Zero Emissions Transportation solutions to the general public with out compromising fun.
I want to thank PopSci for keeping an eye open to our visionary people . I want to thank Juston Gray. you are what American inginuity is all about. You are what will bring back jobs and industry back to our country. Keep up the good work. How do i order one?