Great ride in Northern CA today. One rider who I've only ridden with once crashed in front of me. I was not happy when he showed up as last time I thought he rode too aggressively. We were on a beautiful mountain road , Hwy 70, behind a slow car that would not use the turn-outs. There was a long paved turn-out, the car did not yield, I was in the lead, the rider passes me on the right at full throttle (Kawi Concours 1400) tries to pass the car via the turnout, runs out of pavement, enters gravel at 65+, I start braking, the car continues on. Moron, looses control at about 40MPH, low sides, the bike slides, he tumbles partly into the street and I almost run him over, stopping 20 feet past him. The two trailing bikes stop, I was so pissed I continued on for a few miles. There was moderate damage to the bike but it was rideable. He had great protective gear on and suffered only bruising and some road rash. I'll never ride with this idiot again!