Bike went down outside of Keystone, South Dakota, causing other riders to lose control, lawsuits allege
STURGIS, S.D. – A California company that supplies aftermarket motorcycle parts is being blamed for causing a fatal accident during last year’s Sturgis Motorcycle Rally.
That accident caused a chain reaction of other accidents, according to lawsuits filed against Performance Machine, which does business as Progressive Suspension.
The series of events started when Robert “Bob” Amerson and his girlfriend, Jennifer Sanford, brought Amerson’s 2019 Harley Davidson Road Glide Special to the rally by trailer from their home in Meridian, Idaho, according to a lawsuit filed by Sanford.
On Aug. 1, 2025, Amerson and Sanford road the bike to the Harley Davidson dealership in Sturgis. Progressive Suspension was a vendor at the rally and had a tent at the dealership. Amerson bought a new suspension kit from the company, which company technicians installed. The kit included new components installed on the bike’s front forks, replacing the original parts.
“To install the kit, Performance Machine removed the entire front end of the motorcycle, including removing the original fork pipes from the fork brackets and other front-end components,” Sanford’s lawsuit says.
The next day, Amerson and Sanford were riding with friends. The group had been out for about 30 minutes. The riders were westbound on Highway 16A when they came to a sweeping right curve. As Amerson maneuvered through the curve, the bike began to wobble, according to the lawsuit.
“The motorcycle then unexpectedly tipped and fell on its right side, slid across the center line into the eastbound lane, and struck three motorcycles in a different group traveling eastbound,” Sanford’s lawsuit says. The crash was caught on video.
Amerson and Sanford were thrown from the bike into the oncoming traffic. Amerson sustained fatal injuries.
Three other bikers in the eastbound group have filed separate lawsuits against the company. John Bianco and James and Melody Bardsley claim they were injured because of the accident. The three are residents of Cumberland, Rhode Island.
Following the accident, a licensed engineer inspected Amerson’s bike. The engineer concluded that the installation had been faulty. The left fork pipe was misaligned with the top surface bracket, as evidenced by markings and discoloration that showed the fork moving in the clamp. The bolts were allegedly not tightened correctly.
“The inspection concluded that the wobble, loss of control, and collisions were caused by the loose front forks that Performance Machine failed to properly install,” the lawsuits allege.
Reached by The Dakota Scout Thursday, the company declined to comment.
The lawsuits accuse the company of negligence and product liability. They were filed in federal court.
Sanford is represented by Derek Nelsen and Eric Preheim of Fuller, Williamson, Nelsen & Preheim in Sioux Falls. Bianco is represented by Tyler Haigh of Evans Haigh & Arndt in Sioux Falls, and the Bardsleys are represented by Michael Bornitz of the Cutler Law Firm in Sioux Falls.
