It happened just before 2:30 a.m. Sunday on the connector between Highway 99 and Highway 180.
The California Highway Patrol says a witness saw the man riding at a high rate of speed on the connector.
That's when they say the rider drove off the road, into a light pole, and was ejected from the bike.
Officials say the man died at the scene due to his injuries.
Investigators believe alcohol and speed are factors in the crash.