When the U.S. House of Representatives passed the Build Back Better Act last week, a lesser-recognized provision earmarked some $4.1 billion in tax credits to further stimulate an already booming EV market that Elon Musk hasn’t even dabbled in.
Electric bicycles, better known as e-bikes, have moved from novelty to mainstream with breathtaking speed. They’ve been a boon to hard-working delivery persons during the pandemic (and their impatient customers), and commuters who don’t care to be a sweaty mess when they arrive. And while the scoffing tends to center around the “purity” of cycling—the idea that e-bike riders are somehow lazy cheaters—that electric assist is actually luring people off the couch for healthy exercise. That’s especially welcome for older or out-of-practice riders (which describes a whole lot of folks) who might otherwise avoid cycling entirely, put off by daunting hills or longer distances.
While powerful “Class 3” models especially are trying the patience of pedestrians in crowded cities like New York, with blazing assisted speeds approaching 30 mph, e-bikes are now front-and-center in discussions of future urban mobility. They’re a way to potentially free up precious street space, provide alternatives to automobiles and reduce energy consumption and harmful emissions. California, through its powerful Air Resources Board, recently allocated $10 million in rebates for e-bike buyers, a smaller-scale version of state or federal tax breaks for EV car buyers. The possibilities are fueling cool tech ideas, from covered, rain-proof cargo bikes; to pavement-embedded wireless chargers and automated stabilization systems to help senior riders. CityQ is taking pre-orders for a four-wheeled cargo “bike” that it touts as cycling “with a Tesla feeling.”
In 2020, according to one estimate, 500,000 e-bikes were sold in the U.S. alone—compared to 210,000 plug-in cars.
According to market research company NPD Group, the pandemic helped increase e-bike sales by 145 percent from 2019 to 2020, more than double the growth of traditional bikes. Exact figures on industry sales are hard to pin down; yet The New York Times quoted experts saying Americans bought roughly 500,000 e-bikes in 2020, compared to about 210,000 plug-in automobiles.
Industry analysts expect that uptick in adoption to continue. A report by the Business Research Company shows the global e-bike market growing from $32.5 billion last year to $53 billion by 2025, for annual compound growth of 9.9 percent. Even in bike-saturated Europe, e-bike sales jumped by 23 percent in 2019. And Deloitte expects 300 million e-bikes on the world’s streets by 2023. That’s a lot of bikes, batteries and saved muscle power from thankful riders. If you’re not up to speed on e-bikes, or you’re curious about taking one for a spin, here’s a look at some of the techs, terms and players:
Pedal to the Metal
The tech behind e-bikes falls into two simpler categories, even if the choice between them isn’t as simple. Hub motors integrate a motor directly in the wheel center (either front or rear wheel), in an enclosed system that’s independent from the bike chain and pedal drive. There are two main types: Geared hub motors incorporate internal planetary gears for reduction, allowing the motor to operate efficiently at high rpm while the bike wheel spins at a lower speed. Gearless hub motors directly link the motor’s stator to the bike axle. That reduces a key point of weakness—the toothed gears. Aside from bearings, there are no moving parts, nothing to wear out. Hub motors are relatively affordable, low-maintenance, mass produced by the millions. A do-it-yourselfer can find entire, 800- to 1,000-watt hub motor kits for around $200, where mid-drive power can cost three to five times as much. Hub motors add no extra stress or wear to a chain or shifters, and offer another advantage versus a mid-drive set-up: If a hub motor conks out, you can still pedal home, and vice-versa; if a chain or pedal breaks, a rider can keep moving under electric power. The downsides? Nearly every hub motor has a single gear ratio; fine for the flats, not so good for hill climbs, where the motor can’t match a mid-drive unit for a robust shove against gravity, and may even overheat on long ascents. Hub motors can also make a bike feel unbalanced and awkward to steer—like it’s being pushed or pulled rather than pedaled. Tire changes are more difficult because of the wheel-mounted motor.
Some electric bike companies claim up to 80 or even 100 miles of unassisted range, but expert riders say that would only be possible if most those miles were downhill.
“Mid-drive” bikes, in contrast, locate the motor inside the frame and between pedals at the bottom bracket. Motor power is transferred through the chain drive to the rear wheel. As with EVs, those motors are growing lighter, stronger, quieter and more affordable. The biggest edge—with a parallel downside—is sending power through a traditional chain and gear seat: The motor can deliver major torque up a steep hill or from a standstill, in a lower gear and higher rpm, just as your pedals do.
That energizer-style power keeps going and going, even on long climbs. The major con is the constant surge of power through the poor chain: A pro cyclist can generate roughly 400 watts of per over an hour. Most humans with normal-size thighs can’t manage even half that. But e-bikes can generate up to 750 watts of continuous power. It’s why most mid-drive e-bikes come with uprated chains. And if that chain snaps, you’re not going anywhere, just as on an old-school bike.
On the upside, newer mid-drive motors are notably smaller and lighter than hub units. Hidden inside frames, they’re making some e-bikes look so stealthy that onlookers have no idea it’s electric.
For both types, a speed sensor or torque sensor detects pedal force or wheel rotation, and activates the motor for a helpful forward shove. Riders can typically adjust the level of electric assist, or just pedal harder for a corresponding boost in motor grunt. But mid-drive brings another advantage, with genuine torque sensors to detect the human power applied at the pedal crank, and smoothly dial in electric assist. Hub motors often use a simple cadence sensor at the wheel, and can produce jerky or unpredictable motor boost, especially going uphill.
Battery Range vs. Reality
A big issue with e-bike range claims is that there are so many variables: Rider weight, wind and tire resistance, varying terrain and topography. Some electric bike companies claim up to 80 or even 100 miles of unassisted range, but expert riders say that would only be possible if most those miles were downhill. As a general rule of thumb, throttle e-bikes that combine a 500-to-750 watt motor and a 480 watt-hour (Wh) battery can cover only about 20 miles at best on battery power alone; or less than 25 watt-hours per mile. Pedal-assisted bikes go farther: Figure about 15 watt-hours per mile, or 32 miles from that same 480 Wh battery, with a roughly “medium” level of preset electric assist. The price of that electric boost is weight. A lithium-ion battery usually adds a significant 6 to 8 pounds to the bike; weight that your legs must drive once its energy is depleted.
As the speedsters of the e-bike world, Class 3 models are typically allowed only on “curb-to-curb” roadways or bike lanes, and restricted on bike trails or multi-use paths shared with pedestrians.
Batteries can be mounted on rear racks for easy access and removal, at the price of less-than-ideal location: Too high and too rearward, which can affect handling. Batteries externally mounted on the downtube — the bar directly below the saddle — eliminate that issue, keeping weight low and along the bike’s main axis. Batteries integrated inside the downtube create the sleekest profile, making these e-bikes look less bulky and more like a traditional cycle.
3, 2, 1, Go
Spurred by PeopleForBikes, a national advocacy group and industry trade association, more than 30 states have adopted a “3-Class” system that standardizes e-bikes based on their type of assist and how fast they can propel you. All three classes limit a motor’s go-power to 750 watts, or 1 horsepower.
Class 1 e-bikes generate an electric boost only when you pedal, and reach a maximum assisted speed of 20 mph.Class 2 models also limit assisted speed to 20 mph. But they add a hand throttle, either a grip-twist as found on motorcycles, or a button that can drive the electric motor even when you’re not pedaling.Class 3 bikes are the muscular alternative to Class 1. They’re also exclusively pedal-assisted, but with a maximum boosted speed of 28 mph. Look out, LeMond: That’s roughly as fast as a professional bicyclist can maintain speed for long distances over flat ground.
The roadway infrastructure that each class can use, however, remains a crazy quilt of local, state or national regulations. As the speedsters of the e-bike world, Class 3 models are typically allowed only on “curb-to-curb” roadways or bike lanes, and restricted on bike trails or multi-use paths shared with pedestrians. In Europe, electric mountain bikes, or eMTB’s, are largely welcome on non-motorized trails. For American riders, be aware that the U.S. Forest Service, Bureau of Land Management and National Park Service consider eMTBs as no different from a dirt bike, ATV or other motorized vehicle. So even Class 1 bikes are barred from non-motorized trails. Some states, including Pennsylvania, Utah and Colorado, have made exceptions for trails in state parks.
The Players, And What You’ll Pay
E-bike prices range from as little as $1,200, for a Aventon 350 Pace 350 Step-Through, to $7,500 (or more) for “connected” bikes like the Stromer ST3 Sport. Stromer’s luxurious “e-commuter” brings a powerful rear hub motor (with 600 watts and 44 Nm of torque), fat Pirelli tires, and connectivity features like GPS, remote locking and unlocking, stat readouts and over-the-air updates. Most of the biggest names in cycling have embraced e-bikes: Giant, Trek, Specialized, Schwinn. Even automakers like BMW, focused on expanding their mobility portfolios, are jumping into the game. Last week, Porsche took a majority stake in GreyP, the high-end Croatian bike company started by Mate Rimac, the electric hypercar entrepreneur and creator of the $2.4 million Rimac Nevera. Rimac himself controls Bugatti Rimac, with Porsche holding a minority stake in this newly combined purveyor of fantasy automobiles. That’s all lofty company for a bicycle manufacturer: Imagine a technology trickle-down from seven-figure electric Rimacs and Bugattis to the bicycles you ride for work or play.