E-Bikes Can Travel a Thousand Miles on a Dollar of Electricity
Tom Lombardo posted on January 09, 2020 |
Two new e-bikes are hitting the market in 2020. Let’s check out the technology that makes them go.

City workers have a multitude of transportation options, some more eco-friendly than others. Bicycles offer a zero-emission ride while providing exercise for the rider, but only the most ardent cyclists would attempt to substitute two wheels for four when commuting a long distance. Also, most commuters would not want to show up for work covered in sweat and out of breath. Electrically assisted bicycles—or -e-bikes—are propelled by a combination of pedals and electricity. This can offer a nice compromise, allowing the rider to pedal with help from an electric motor when desired. Oh, and they don’t add to the city smog either—a nice bonus.

Two companies are releasing new e-bikes that will be available in 2020. Let’s check out the bikes and the technology that makes them go.

E-Bike Definition

The term “e-bike” is often casually used to describe all electrically assisted bicycles, but some countries make a legal distinction between various types of electric bikes. In those cases, “e-bike” refers to an electrically assisted bicycle whose motor can be engaged either through pedaling or by a throttle. That’s sometimes called a “power-on-demand” bike because the rider can choose when to turn on the motor, even if they’re not pedaling. A bike whose motor engages only while the bike is being pedaled may be called a “:pedelec”—a morphing of the words “pedal” and “electric.” Throughout this article, we’ll use “e-bike” in a generic sense, meaning any electrically assisted bicycle.

Pedelec and S-Pedelec

Pedelecs are broken into two categories based on their maximum speeds. A pedelec’s motor will engage when the bike is being pedaled and will disengage when the bike reaches a speed of 32 km/hr (20 mph)—the maximum allowable for a pedelec in most locations. A speed pedelec (or S-pedelec) can achieve speeds of 45 km/hr (28 mph), and may be considered a motor vehicle in some localities, which means that the rider must be licensed and insured. If you’re considering an e-bike, check your local ordinances to be sure you’re in compliance.

Drivetrain Technology

A bicycle’s drivetrain consists of the source of propulsion (pedals and motor), the crankset (the point where the pedals spin the main sprocket), and the transmission (gears). Most pedelecs use brushless DC (BLDC) motors, which are inexpensive, lightweight, reliable and efficient. E-bike motors can typically deliver between 250 and 750 watts of power (⅓ to 1 hp). A BLDC motor requires a sophisticated controller, usually in the form of an inexpensive microcontroller with some power electronics to regulate its speed and torque.

Hub motors are located in the center of one of the wheels, driving the wheel directly. They’re relatively inexpensive, but they don’t provide a lot of torque. This can be remedied by adding a planetary gear system to the motor, but that increases its cost and complexity while also decreasing its reliability. Some hub motors even include a fully automatic continuously variable transmission (CVT). A hub motor can be attached to the bike’s front or rear wheel, but either way, it will shift the bike’s center of gravity, which affects its handling.

Here's how a bicycle hub motor’s CVT works:

(Video courtesy of Fallbrook Technologies.)

Mid-drive motors reside in the bike’s crankset. This configuration lets the electric motor take advantage of the bike’s existing gears, a combination that delivers more torque than what a hub motor can provide—a very nice feature when riding on hilly terrain. Since the mid-drive motor is located directly under the rider, it has a negligible effect on the center of gravity, making the bike easier to handle. The trade-off is that mid-drive motors are more expensive than hub motors. E-bikes with mid-drive motors use a standard derailleur gear set—the same gearing system found on pedal-only bikes—although the size of the gears may change to compensate for the electric power available.

A conventional derailleur gear set. (Image courtesy of Keithonearth [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)].)
A conventional derailleur gear set. (Image courtesy of Keithonearth1.)

Unlike hub motors, which spin whenever the bike is moving, mid-drive motors don’t spin while coasting, which makes them unsuitable for regenerative braking.

Like electric cars, e-bikes use batteries as their “fuel tanks.” The most common type, not surprisingly, is the lithium-ion battery. A typical e-bike battery may provide a range of 50-200 km (30-125 mi), but the exact range depends largely on riding conditions. The batteries normally mount to the bike’s frame and are detachable, so they can be brought inside a building for recharging.

Removable e-bike battery. (Image courtesy of FUELL.)
Removable e-bike battery. (Image courtesy of FUELL.)

Now that we’ve covered the basic technology, let’s take a look at two e-bikes that will be hitting the market in 2020.

FUELL Flluid

Erik Buell founded the Buell Motorcycle Company, which merged with Harley-Davidson in the early 1990s. Buell later joined forces with François-Xavier Terny and Fred Vasseur to create FUELL, a maker of electric motorcycles and pedelecs.

Flluid is FUELL’s high-end, low-maintenance pedelec that’s available in two models: the standard pedelec, which can reach speeds of 25 km/hr (15 mph), and the speed pedelec, which can cruise at 45 km/hr (28 mph).  

The Flluid pedelec. (Image courtesy of FUELL.)
The Flluid pedelec. (Image courtesy of FUELL.)

Flluid Mechanics

The Flluid features a 500-watt mid-drive motor coupled with an eight-speed, external geared hub, making a powertrain that’s capable of delivering 100 Nm of torque. An integrated torque sensor measures the amount of force applied to the crank, which improves its pedal-assistance performance. A pair of removable Li-ion battery packs provide just over one kilowatt-hour of energy, which gives the e-bike a range of 200 km (125 mi), depending on conditions. With an average U.S. electric rate of $0.12/kWh, the Flluid can travel a thousand miles on one dollar’s worth of “fuel.” A plug-in charger brings the batteries up to 80 percent capacity in 2.5 hours or to 100 percent capacity in five hours.

Flluid’s aluminum alloy frame offers a reasonable compromise between weight and cost, and its Suntour XCR34 front-end suspension provides 120 mm (4.7 in) travel. The bike weighs in at 31 kg (69 lb).

Flluid Motion. (Image courtesy of FUELL.)
Flluid Motion. (Image courtesy of FUELL.)

Other Flluid Features

Flluid also sports a 900 lumen LED headlight and an 8 cm (3.2 inch) color touchscreen. For security, the Flluid includes a foldable lock and requires a PIN code to access its dashboard. It also includes GPS tracking in case the bike is stolen.

FUELL is taking orders for the Flluid, which is priced at $3,895 for the base model. The company expects the Flluid to ship in February 2020.

X One

E-bike maker Rayvolt is in the midst of a crowdsourcing campaign to fund its latest creation, the X One. The base model’s full price of $3,999 is comparable to the Flluid, but Rayvolt is offering a discounted price of $1,999 for the first two people to preorder one via the Indiegogo page.

X One E-bike. (Image courtesy of Rayvolt.)
X One E-bike. (Image courtesy of Rayvolt.)

X One Hardware

The X One features an aluminum composite frame with a carbon fiber fork, keeping its weight down to 20 kg (44 lb). Rather than a torque sensor, the base model X One employs a gyro that measures the grade with a tilt sensor to deliver optimal torque when climbing a hill. (The high-end models include both a torque sensor and a gyro.) The tilt sensor also recognizes when the bike is going downhill, which triggers its regenerative braking capabilities. Regenerative braking is also engaged when the rider applies the bike’s hand brakes. A 250-watt hub motor lets the X One reach 25 km/hr (20 mph), and its removable battery pack, which can be fully charged in under four hours, provides a range of up to 50 km (31 mi). Higher-end models include a 750-watt motor and a larger battery pack, increasing the speed and range to 45 km/hr (28 mph) and 75 km (46 mi), respectively.

X One Features

The X One’s touchscreen is removable for added security. Facial recognition unlocks the bike and loads the rider’s personal settings. The bike responds to commands via its touchscreen as well as voice commands. It also recognizes certain body movements (such as tilting one’s head to the side) to trigger the turn signals. A light sensor will turn on the head and tail lights when it gets dark.

Rayvolt is taking orders for the X One through its Indiegogo page. The company plans to start production in February 2020—a mere 18 months after its conception—and expects the bike to ship in June 2020.

With more than 250 million e-bikes on the road today—mostly in China and Europe—and another 30 million added every year, more people are seeing the health, environmental and financial benefits of motor-assisted pedaling. Will their popularity cross over to North America? We’ll see.

1Keithonearth -- CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)

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