The Ann Arbor, Michigan HOG Chapter kindly provided the below graphics. They are used with their permission.
With your right or left arm extended, move your finger in a circular motion.
Extend your right arm at a 45 degree angle and point towards the hazard.
Extend your left arm upward at a 45 degree angle with your index and pinkie finger extended.
Raise your left arm horizontal with your elbow fully extended.
Raise your left arm up and down with your index finger extended upward. This indicates the leader wants to speed up.
Raise your left arm and repeatedly move up and down in a pulling motion.
Raise your left arm horizontal with your elbow bent 90 degrees vertically.
Extend your left arm at a 45 degree angle and move your hand up and down.
Extend your left arm at a 45 degree angle and point towards the hazard.
Position your left hand over your helmet with your fingers extended upward.
Extend your left arm at a 45 degree angle with the palm of your hand facing rearward.
Not For The Police
Extend your left arm straight out with your elbow bent 90 degrees. Carefully extend your middle finger to clearly demonstrate your dissatisfaction with the other guy. NOTE: It is not recommended you do this when you are alone.