The coming of the electric motorcycle
May 31, 2005 Electric motorcycles are in their infancy but there’s a realistic promise of electric motor performance that is more suited for the racetrack than that of internal combustion engines and infinitely better suited for the road. As the first electric bikes find their way onto racetracks and begin mixing it with two and four strokes, it appears you need three times the horsepower in a gas-powered motor to get a bike as fast as an electric bike. And then there’s the new 500bhp 67 Kg Symetron electric motor which should really kickstart performance electric automobiles and bikes. Personal electric vehicles have always struggled to capture the attention of the masses. While electric vehicles held their own in the early years of motoring and indeed held the land speed record for a time, battery technology was simply not ready and electric vehicles eventually perished against the power and range of vehicles powered by the internal combustion engine, not to mention Henry Ford’s cost efficient mass production techniques.
In the early years, mobility was the unique proposition which drove sales of all automotbiles but as penetration rose to the point where most people had a car, mass marketing was called upon to stimulate demand and since that time, automobiles and motorcycles have been largely sold on emotion.
Most registered road-going conveyances can do at least twice the speed they are legally allowed to do, and there’s a growing percentage that can triple the speed limit. For motorcycles, that percentage is much greater than with cars.
A high performance internal combustion engine snarls and growls and appeals to base emotions. Electric motors don’t snarl. In their most familiar form they drive rather than power a range of domestic appliances we do not equate with passion or brute force - electric toothbrushes and carving knives, hedge trimmers, can openers, screw drivers and, heaven forbid, dentists drills.
Despite a rash of high performance fuel cell, hybrid and electric prototype show cars from Honda, Toyota and Mitsubishi designed to promise the future, electric power is still largely regarded as the domain of tree huggers and greenies and the radical left. Performance electric cars are seen as at worst fictional, and at best, rare and expensive and they are not made by Ferrari, McLaren, Lamborghini, Koenigsegg or Bugatti. No-one would sell the children to buy one.
Which leaves a rather large gap in the market, because the time is already here when electric motors can “do the business.”
Brutally powerful electric motors are already here
Raser Technologies, a technology licensing company that develops and licenses advanced electric motor, controller and related technologies, released independent test results last month at the Society of Automotive Engineers World Congress in Detroit that measured the combined effectiveness of its P2 Symetron motor and controller technology working together as a drive system.
The test was at an independent dynamometer testing facility in Detroit and showed that a Symetron P2 motor driven by a matching Symetron controller consistently delivered more than 420 ft-lbs of torque on numerous test runs. In each test run more than 420 ft-lbs of torque was measured for a minimum duration of 60 seconds.
The Symetron motor is 8 inches long by 12.5 inches in diameter and weighs just 67 Kg. This small size combined with high torque yield a torque density of 35 Newton Meters per Liter. Raser believes this to be the highest torque density for any drive system available today.
High torque is a critical performance requirement for an electric motor in automotive drive system as it provides the power needed to help accelerate the vehicle. Previously it was thought that the use of costly permanent magnet material was necessary to achieve the high-torque density needed for such an application.
Read our story on the Leblanc Caroline and Mirabeau cars and you’ll see that the secret to rapid acceleration is not brute horsepower but a good power to weight ratio. Lowering the weight has the same effect as increasing the horsepower, with a range of ancillary benefits. Electric motors don’t offer a big weight saving in a car, particularly with the weight of batteries to be considered. The lighter the batteries, the more expensive they are, or the shorter the range.
But a motorcycle already has a big power-to-weight advantage to begin with and if you’re prepared to put up with a modest range, the light weight of an electric motor can offer a compelling performance package. A motor of the ilk of the Symetron P2 motor is not required to produce startling performance from a motorcycle, and there are already several examples of this.
The Electric Moto Blade
Electric Moto Corporation builds an electric motocross bike named the Blade which delivers horsepower roughly equivalent to a 250 four-stroke motor but with much more torque low in the rev range. The interesting thing about the Blade, apart from its terrific performance and complete lack of noise or pollution, is that the controller can be programmed and hence the power curve can be tailored to suit a rider’s abilities. Unfortunately, the Blade is not street legal but it’s well worth keeping an eye on.
Perhaps the most interesting work in the areas of performance motorcycles is being done by Todd Kolin of Electric Motorsport in Oakland California.
Electric Motorsport's Supermotard and GPR Road Racer
Electric Motorsport sells a range of electric two wheelers from the likes of Currie Technologies, Oxygen, Vego and EVT but by far the most interesting machines they offer are significantly modified Derbi motorcycles.
Derbi is one of the great names of European motorcycle racing, having won 85 Grands Prix and eight World titles, all of them in the 50cc, 80cc and 125 cc classes, and hence having expertise in building exquisite small capacity motorcycles. Last year the marque won three 125cc Grands prix, including the Dutch TT at Assen.
Derbi makes a range of small-capacity (50cc), high-performance, road-registerable motorcycles in both roadrace replica and supermotard replica configurations and Electric Motorsport modifies these machines to make them electric motorcycles and sells them to the public.
“The Derbis come with 50cc two-stroke engines with a six speed transmission,” Kolin told Gizmag. “They come in supermotard or road race replica versions and we’ve now done a few supermotards and they work really well.”
“We pull the 50cc motor and transmission and sell it and then install an electric motor, the batteries and the controller. There’s a lot of other minor work. We change the throttle, do some major frame modifications, cut out some things and weld on others. Do a lot of metal fabrication on the frame and then repaint it.”
Reworking the Derbis works well for Electric Motorsport as it enables a motorcycle with an exceptionally high quality to be produced, with superb running gear, suspension, brakes, electrics and all ancillaries. “If we were making a bike from scratch, we’d need to go through a lot of hoops to get it Department of Transport certified as street legal”, says Kolin, “and we’d also need to become licensed as a manufacturer, so by doing a conversion, we don’t need to do that.”
When we speak to Koiln he is highly enthusiastic about the new supermotard.
“When we first built it, we took it to the racetrack the next day as there was a race meeting and we wanted to get some track time to sort it out and see how well it went. We entered it in the open class and went out in the heat race and . well, it blew everything away and won.”
“It was much faster than the original 50cc supermotard. They don’t have too much juice as a 50cc two-stroke but as an electric bike they are putting out a peak of 15 horsepower and they have just so much more torque,’ he says.
Unlike the 50cc version which comes with a close ratio six speed gearbox, the electric motor doesn’t have a clutch or a gearbox. When the bike is at a standstill, so is the motor.
“We run them as automatic,” says Kolin. “There’s only one gear and a reduction direct drive to the rear wheel, whereas the gas motor uses the six speed gearbox. Even with the six speed gearbox, the 50cc motor isn’t in the hunt. We’ve run them head to head – the supermotard gas version against the electric version - and the electric version just smokes it.”
Currently, the electric version weighs in “around 50 to 60 pounds” heavier than the petrol version. “The electrics are heavier, because they’re lugging around a lot more lead, says Todd. “With better battery technology, it would lighten it up a lot. Nickel metal hydride batteries would lighten it considerably but they would cost more money.”
Currently, the price of the electric bike is around twice what of the normal petrol Derbi. “A brand new one with zero miles on it would cost around US$6800 with the 48-Volt SLA Battery pack. “The price varies because some people want a longer range, while others don’t care so much about the range and want high performance and more power is what they regard,” saysd Kolin. “We build to their specs.”
“Some people want to have it go 60mph while others are happy to cruise around town at 40mph so we set it up the way the customer wants it. There’s usually about a 30 day lead time for us to manufacture a bike the way people want it, from the time they pay their deposit until it’s ready for delivery.”
The road race replica GPR and supermotard both come in around US$6800, giving a bike with around 18bhp and a top speed of 52 mph.
A longer range and slightly lighter weight costs around US$400 more, and that brings with it a set of 48 Volt NiZn Evercell MB 5O Batteries and a speed charger.
If you want a very fast machine, capable of 65mph with acceleration equivalent to a high performance two stroke 250cc motorcycle, the engine can be upgraded to an output of 27 bhp by swapping in a different controller.
“To get 27 bhp, the only thing we really need to change is the controller, so instead of a 300amp controller, we put in a 650 amp controller so it’s just the amps on the controller and that’s about an extra US$400.”
“The controller is programmable with any Windows-based PC which allows the bike’s performance to be adjusted to meet the needs of the rider for range, acceleration, torque, and throttle response.
“Sometimes we use race batteries which can deliver more amps than the standard lead acid too.”
So far, Electric Motorsport has built around a dozen GPRs and two Supermotards, though the future is clouded as Derbi was recently sold and the future supply of the rolling chassis is unclear. “Piaggio, that owns Vespa, has just bought Derbi, so Piaggio, Vespa and Derbi are now all the same company and they are reorganising their distribution here and we’ll have to wait and see.
“Ideally what we’d like to do is have the design manufactured by Derbi or another manufacturer,” says Kolin. “The price is high right now because they are custom made as a one-off motorcycle for people who want something different. If they were made by Derbi the price would come down at least 30 or 40 percent and maybe more,” he said.
And that’s the interesting part, because although we’re looking at a motorcycle that costs a 50cc price, the electric motorcycle that is built on the same chassis, has the performance of a red blooded 250 two stroke. Perhaps not quite the same maximum power output (approximately half), but an electric motor makes its maximum torque at the bottom of the rev range, so it punches out of corners quicker than a motorcycle of 500cc would, all with complete control as the torque curve is almost linear.
One person with quite a deal of experience of racing electric motorcycles against two-strokes is Cary De Witt of Eveez. Eveez has been racing a pocketbike for 18 months now and has yet to be beaten by any motorcycle, of any capacity. Check out this video showing the startling performance of the Eveez machine against a field of two-stroke motorcycles.
De Witt told Gizmag, “as a the general rule of thumb, to equate race potential between electric and petrol engines on tight to medium racetracks, multiply the horsepower rating by three. That is, if you have a 10kw electric motor, you’ll need a 30kw petrol motor to stay with it.”
All this augers well for electric motorcycles. Imagine the P2 Symetron motor in a motorcycle with its 420 foot pounds of torque. That would be a motorcycle capable of mixing it with just about anything with an internal combustion engine.
It might not snarl and roar, but it would be one hell of a motorcycle.
NOTE: Though Electric Motorsport produces performance electric bikes, the company also wholeheartedly supports the electric vehicle as an environmentally neutral vehicle.
“We are here because we want to support renewable energy transportation,” says Kolin.
“A lot of our customers have solar systems. Last night I delivered a new Oxygen scooter to a customer who has a solar array on his roof. So he can charge his vehicle off the solar panels on his house and that way he doesn’t have to pay for any petrol to get to and from work.”
“If you have electric vehicles you can use windpower, solar, geothermal, hydroelectric, just about any renewable power source to charge, and if that’s the way you get your power, then it becomes a true zero emissions vehicle.
“And that’s really worthwhile.”