WHILE OUT RIDING WITH MY MEETUP MOTORCYCLE GROUP ALONG BACK COUNTRY ROADS ON THE EASTERN SHORE OF MARYLAND. WE WERE APPROACHING A SHARP RIGHT HAND TURN IN THE ROAD WHEN I FIRST APPLIED MY BRAKES THE BRAKES NEVER COMPLETELY ENGAGED. AFTER REAPPLYING THE BRAKES IN A PANIC STOP CONDITION THE ABS SYSTEM NEVER KICKED IN, HOWEVER THE REAR BRAKES DID EVENTUALLY ENGAGE RESULTING IN THE BIKE LAYING DOWN A LONG SKIDMARK AND THE REAR TIRE GOING INTO A FISHTAIL MOTION. THE RESULT WAS I CROSSED OVER THE ONCOMING TRAFFIC LINE AND END UP OFF OF THE ROAD ON THE WRONG SIDE OF THE STREET. PRIOR TO ALL OF THIS A COUPLE OF TIMES DURING OUR RIDE THE FRONT END OF THE BIKE WOULD OSCILLATE AT HIGHWAY SPEEDS FOR NO APPARENT REASON. ONE OF THE RIDERS HAD A GOPRO VIDEO RUNNING, WHICH CAUGHT PORTIONS OF THE INCIDENT. THE FRONT BRAKE SYSTEM BRAKE FLUID WAS REPLACED A COUPLE OF MONTHS PRIOR TO THIS INCIDENT. I BELIEVE THE REAR BRAKE FLUID WAS REPLACED A FEW MONTHS PRIOR TO THAT, HOWEVER I HAVE NOT YET LOCATED THE SERVICE RECEIPT FOR THE LATTER. I LOOKED AT THE FRONT BRAKE FLUID RESERVOIR WINDOW AND DID NOT SEE ANY FOAMING. IT DID NOT OCCUR TO ME AT THE TIME TO CHECK THE REAR BRAKE RESERVOIR. ALL OF THE RIDERS STOPPED IN THAT TURN I WAS MORE CONCERN WITH GETTING US OUT OF THAT CORNER THERE IS ONLY ONE LANE OF TRAFFIC EACH WAY.