CHP says a group of more than a dozen motorcyclists were heading up the northbound lanes of the freeway around 1 p.m. when an SUV in front of them started to slow down.
One of the riders hit the brakes causing him and another motorcyclist to fall.
They were both taken to the hospital to be treated for injuries.
Traffic was backed up for close to an hour on both sides of the highway as CHP cleared the road.