Imagine sitting in Interstate 880 gridlock when you spot a motorcycle approaching in the rearview mirror. Instead of the thump reverberating off car doors, all you hear is the faint, high-pitched whir of an electric motor as the big machine passes.

Though electric motorcycles don’t make much noise, their adoring fans are growing louder each year. Once regarded as a novelty, e-bikes are creeping into California’s famed motorcycle culture. And for some motorcyclists, the latest fleet of electric bikes has nearly bridged the performance gap with their combustion-engine counterparts.

“It feels like you’re flying,” said Curtis Schwebke, 58, of Los Gatos, who has ridden motorcycles for 15 years. “I used to fly a hang glider, so I know the feeling, and it’s pretty close to that.”

Schwebke became intrigued with e-bikes in September 2009, when he attended a tech convention in San Francisco and saw a machine manufactured by Zero Motorcycles. He quickly scheduled a test ride at the company’s headquarters in Scotts Valley and, after that first twist of the throttle, honed in on the e-bikes’ most prominent feature: the torque.

While gasoline-powered cars and motorcycles have to cycle through gears to speed up, many electric motors simply go. There is no delay between shifting gears, only the raw sensation of acceleration. It’s akin to the first few seconds of a roller-coaster ride, just prolonged and packed into a throttle. Schwebke described the experience as a “precise feeling of control.”

For some riders, that sensation alone is enough to win them over. Since his fateful ride in Scotts Valley, Schwebke purchased one of Zero’s 2014 models and installed solar panels to charge the bike, which he uses to commute daily to his Santa Clara office.

Power isn’t the only feature that’s helping e-bikes catch up to gas-powered ones. Many motorcyclists have long regarded electric motorcycles as more of an oddity than a viable option. They were interesting, but they couldn’t go as far or fast as gasoline-powered bikes.

That was true a decade ago, when electric motorcycles were barely competitive with scooters and Zero’s machines resembled bicycles more than an honest motorcycle. Today, Zero’s flagship model, the $15,995 SR, can reach 100 mph and travel almost 200 city miles on a single charge.

The bikes were fitted with adjustable suspension in 2015, which made them handle like “real” motorcycles. The key to their quick development was improved battery technology, which draws innovation from other technological pursuits, like making longer-lasting laptops and cellphones.

“We are, without a doubt, selling more bikes today than we ever have,” said TJ Aguirre, a Zero spokesman.

Zero isn’t the only player in the game. Victory Motorcycles, an Oregon-based e-bike manufacturer, produces the Empulse TT, a $19,999, all-electric bike that can travel more than 100 mph and has a range of 140 miles.

Even major manufacturers are rolling out concept bikes at shows and events. Harley Davidson debuted its concept electric bike, the Livewire, in the 2015 Avengers movie, “Age of Ultron.” Still, less than 1 percent of new motorcycles are now e-bikes, although industry analysts are predicting steady growth over the next decade.

Aguirre said that his company’s sales pitch doesn’t entail trying to pry gas-powered bikes from their owners. “I don’t know if there’s anything you can really say to convince anybody,” he said. “Motorcyclists are finicky people.”

He was hinting at the fact that few people in the U.S. purchase motorcycles out of necessity.

It’s something people opt into, whether their motivation is fun, functionality or fashion. Because of the finickiness, motorcycle manufacturers have to appeal to riders’ hearts before their minds.

Some e-skeptics express concern over range for electric motorcycles and cars, said Piet Canin of the Santa Cruz environmental group Ecology Action. “People tend to think, ‘I need a car that I can drive to Tahoe.'” But Canin dismisses that concern because “most people that say that aren’t driving to Tahoe very often.”

Fred Olsson, 45, isn’t concerned at all about range. He test rode Zero’s SR model Saturday at a demo event at San Jose BMW, hoping to find something to find some wheels to commute from his Cupertino home to his job in San Jose. The ex-motorcyclist was still mulling the purchase on Saturday afternoon, but seemed impressed: “It was more power than you need. Superfast. Fun to drive.”

Some motorcyclists, however, are hesitant to abandon their mechanical knowledge to purchase a bike they don’t know how to fix. Despite the fact that electric motors are far simpler than combustion ones, which contain hundreds of moving parts, people are generally less comfortable fiddling with batteries.

“With combustion bikes, you can pretty much repair them on the road,” said Jeremy Allen, 38, of Santa Cruz, an owner of a gas-powered motorcycle who is reluctant to go electric because he wouldn’t know how to tend to a malfunctioning battery. With combustion bikes, Allen said, “You can pick up a part at a shop and work on it in the street to get your bike running again.”

Fixing your own machine isn’t just a matter of practicality for some riders; it’s also sentimental.

Some riders simply enjoy the satisfaction of tinkering with their machines — or, like Robert Vigurs, of Santa Cruz, they crave the vibration of a motor and the crack of a booming exhaust.

“I really like that feeling of the explosions inside the motor,” said Vigurs, who’s been riding for over 40 years. “It fires like ‘bang bang, bang bang.’ There’s something about that motor sitting right below me, and it’s vibrating and it’s got that growly kind of sound to it, like a tractor with big old pistons moving up and down.”

The 63-year-old Vigurs, sporting a full beard while sitting atop his Harley Davidson, drummed on his gas tank to convey the sensation of a rhythmically thumping motor. He said he enjoys the noise for therapeutic reasons, explaining that it eases him when he’s frustrated.

“I just hop on this bike and go,” he said. “It’s noisy and it’s loud and it’s right on. It feels good, you know.”