Authorities have identified the 51-year-old bicyclist killed in the Santa Monica Mountains near Malibu on Saturday.
Robert Eugene Hyndman of Laguna Beach, who was riding with his brother at the time of the accident, drifted onto the wrong side of Las Flores Canyon Road north of Hume Road around 11:45 a.m. Saturday.
Authorities said Hyndman hit a guardrail and was thrown head-first onto the ground, suffering head injuries in spite of his helmet.
Hyndman was taken to UCLA Medical Center, where he was pronounced dead at 12:38 p.m., according to the California Highway Patrol.
The CHP said the road has many sharp curves and is challenging for even experienced riders.