The rider, whose name has not yet been released, was entering southbound Highway 101 at 10th Street at about 2 a.m. when, for unknown reasons, he was ejected from the bike, the CHP said.
The CHP said the bike remained on the roadway while the rider fell about 30 feet down to the roadway below the on-ramp.
The crash was cleared from the roadway around 3:15 a.m. Further details were not immediately available.
