For Sunday’s record-breaking attempt, Denise Mueller-Korenek rode a custom-designed machine featuring a unique double drivetrain capable of propelling the bike forward 128 feet with each revolution of the pedals, a necessity for hitting speeds surpassing the takeoff velocity of the typical commercial jetliner. By contrast, a typically geared bike might travel about 17 feet with each pedal revolution, and racing bikes used in competitions like the Tour de France hit around 30 feet per turn of the pedals in their highest gear.

Gear ratios. (Christopher Ingraham/Christopher Ingraham/The Washington Post)

Because of the extreme gearing of the bike, Mueller-Korenek was towed for the first two miles of the five-mile course behind a dragster driven by Shea Holbrook, a professional racecar driver. At a speed of over 100 mph, Mueller-Korenek released the cable attaching her bike to the rear of Holbrook’s car and pedaled the remaining three miles on her own. She benefited from the aerodynamic boost provided by the dragster, speeding along just inches ahead of her front wheel.

Vehicle-assisted speed records are nearly as old as the modern bicycle itself. As early as 1899, an American named Charles “Mile-a-Minute” Murphy hit a speed of 60 mph in the wake of a Long Island Rail Road train. Subsequent speed records were set with the assistance of motorbikes, cars and eventually racecars designed specifically for the purpose.

Paced bicycle speed record history. (Christopher Ingraham/Christopher Ingraham/The Washington Post)

Pursuing the motor paced record is a dangerous pastime given the high speeds involved, as well as the proximity to a souped-up vehicle. Rompelberg, the previous record holder, broke 24 bones in one of his first attempts to break the record after his pace car began fishtailing at 140 mph, flinging him out of the slipstream and into the air.

Mueller-Korenek set a women’s speed record of 147 mph in 2016. It took her two years to return to the salt flats to attempt to best the men’s record, in part because of a string of setbacks in 2017: a crash that broke a shoulder blade and a rib, as well as an accidental self-inflicted gunshot wound to the leg.

Mueller-Korenek, the CEO of a home security firm and a mother of three, is the first woman to hold the speed record. “Denise & I are the only women in the history to attempt and now hold this record,” her driver, Holbrook, noted on Facebook.

The paced record is one of a number of different cycling speed records, which vary by the equipment and rules involved. The top speed for a human-powered bicycle without any vehicle assistance is 89.6 mph, set on a recumbent bicycle fully enclosed by a bullet-shaped fairing. For a traditional upright bicycle without any aerodynamic assistance, the closest analogue to Mueller-Korenek’s record is probably the 200-meter track time trial, which the current world record holder completed at a speed of about 48 mph.

Mueller-Korenek isn’t the only woman to recently demolish a long-standing cycling record held by men. In 2017, Florida cyclist Amanda Coker biked 86,573.2 miles in a single year, surpassing the previous mark by more than 10,000 miles. To pull it off she averaged about 237 miles per day.