On Sunday September 16, 2018, Denise Mueller-Korenek broke the bicycle land speed record of 167 mph, hitting 183.932 mph at Utah's Bonneville Salt Flats. This story about the engineering and logistics behind this crazed effort originally ran on Thursday, September 13.

When you’re trying to become the fastest self-propelled human on the planet, you wouldn’t expect getting going at all to be the hardest part. But Denise Mueller-Korenek rides a bicycle so intense, even she can hardly pedal it. At least, not at the speeds hit by any sane cyclist. Once she’s going Autobahn speeds, though, she can unhook from the drag racing car that tows her off the line and start to crank the gear around. Drafting off the steadily accelerating racer and spinning up the rpm's on the bike’s compound reduction gear, she’ll have two and a half minutes to reach the goal that brought her to Utah’s Bonneville Salt Flats this weekend: set the motor-paced bicycle land speed record. Which right now stands at 167 miles per hour.

Accelerating past the takeoff speed of a Boeing 757 on a bike seems impossible, but a top-flight cyclist riding a remarkable bike and drafting the right vehicle piloted by the right driver can make it happen. That is, as long as everything—from physics to fitness, technology to team—works perfectly.

At 45 years old, Mueller-Korenek may be the ideal candidate. As a junior cyclist she won 13 national championships in road, track, and mountain bike racing, before anxiety led her to quit the sport. She spent the next 20 years running a business, raising three sons, skydiving, and racing Mini Coopers. She returned to bike racing five years ago and won two more age-group national titles. Even now, few men can hold her wheel when she opens up a sprint, says her coach, John Howard, who set a previous record, at 152 mph, in 1985. And she has the technical skills to match her explosive aerobic engine. “She’s a world-class bike handler.”

Howard, who coached Mueller-Korenek when she was a junior, got her back into the sport with a simple truth: No woman had ever attempted a speed record. “That was like a match to gasoline,” says Mueller-Korenek.

This weekend’s attempt comes two years after Mueller-Korenek hit 147.7 mph on her bike at Bonneville, setting the women’s speed record (by virtue of being the first woman to try it). She had planned to go for the all-time mark the next day, but thunderstorms rolled in, drenching the salt flats and nixing her chance. The speedy cyclist has changed a few details since, but the core of her approach hasn’t changed. It’s all about having the right equipment and the right team.

Pedal to the Mental

For a vehicle that will reach such eye-tearing speed, Mueller-Korenek’s KHS bike has the approximate aerodynamics of a chopper motorcycle—the wind-blocking car means the bike can serve other priorities. At 35 pounds and more than 7 feet long, it’s twice the size of a normal bike. The low-slung frame features geometry cribbed from the bike that Dutch cyclist Fred Rompelberg used to set the existing record at 167 mph in 1995. The walls of the hollow carbon-fiber frame tubes are three times thicker than those of conventional frames. The 17-inch tires were swiped from a motorcycle, since no cycling rubber is rated for anything near these speeds. A steering stabilizer and a custom-tuned suspension fork borrowed from downhill racing dampen irregularities in the unpaved salt track. The compound reduction gear—essentially two drivetrains joined together—is five times larger than a conventional racing bike’s top gear. That’s why pedaling from a standstill is like trying to start a car in sixth gear.