Some in the large, helmeted crowd still were processing the death of their friend.
Others didn't know Steve Norwick, but wanted to show respect for the man and share his love of bike riding.
About 200 cyclists turned out Sunday morning in memory of Norwick, 68, a newly retired Sonoma State University professor who died this summer after being hit by a car while on his weekly Friday morning bike ride.
Memorial Ride For Steve Norwick
"It's a real honor to see how many people have been thinking about my husband and what happened to him," said Marthe Norwick, standing in the crowd with her bike helmet on, ready to ride.
On June 8, Norwick was riding with a friend along Petaluma Hill Road, headed for breakfast in Penngrove.
A pickup truck struck Norwick and knocked him from his bike. He died 12 days later.
Driver Robert Cowart, 68, who didn't stop, was later arrested. He's been charged with felony hit-and-run and manslaughter.
Sunday's ride marked one month since the collision.
Arriving in packs and in singles, the riders met up in the courtyard of the Spreckels Performing Arts Center on Snyder Lane in Rohnert Park.
Many in the crowd knew Norwick. They included former students, colleagues and family friends. But there also were people in the crowd who had never met him.