Here are some nifty graphical-type representations of the hand signals we use. They were originally created by a guy called Iron Butt who's with Ann Arbor, MI American HOG. I appreciate them letting us use 'em!
Start Engines
With your right or left arm extended, move your index finger in a circular motion. (This is usually initiated by the ride captain.)
Left Turn
Raise your left arm horizontal with your elbow fully extended.
Right Turn
Raise your left arm horizontal with your elbow bent 90 degrees vertically.
Hazard to the Left
Extend your left arm at a 45 degree angle and point towards the hazard. Try not to look like you're waving to someone.
Hazard to the Right (A)
Extend your right leg at a 45 degree downward angle to signal the hazard.
Hazard to the Right (B)
Extend your left arm upward at a 45 degree angle with your elbow bent to 90 degrees and point towards the hazard over your helmet. (You don't see this signal very often. Snowman uses it occasionally.)
Speed Up
This is given by the leader only. Raise your left arm up and down with your index finger extended upwards. This indicates the leader wants to speed up.
Slow Down
Extend your left arm at a 45 degree angle and move your hand up and down, with your palm down.
Stop
Extend your left arm at a 45 degree angle with the palm of your hand facing rearward.
Single File
Position your left hand over your helmet with your fingers extended upward. This indicates the leader wants the group in a single file formation. Usually this is done for safety reasons.
Staggered Formation
Extend your left arm upward at a 45 degree angle with your index and pinkie finger extended. This indicates that the leader feels it is safe to return to staggered formation.
Tighten Up
Raise your left arm and repeatedly move it up and down in a pulling motion. This indicates the leader wants the group to close ranks.
I'm A Bit Upset
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.