It happened along the northbound lanes, just south of Culver Drive, shortly after midnight.
Details about the crash are limited, but according to witnesses, the two motorcyclists were reportedly riding in a large group on the freeway. All northbound lanes were closed for about four hours before reopening.
While deputies were on the scene of the crash, a separate driver rear-ended a California Highway Patrol vehicle.
It's unclear if anyone was injured or if any arrests were made.
In video obtained by Eyewitness News, a person is seen being detained after reportedly failing a DUI test. Footage also shows a CHP vehicle with visible damage.
Both incidents remain under investigation.