Empulse Powertrain Lash
Riders who are new to the Empulse will notice a jerk when starting the bike from a stop. This is sometimes referred to a "the clunk", but the correct name is "powertrain lash". This page will discuss the causes, and techniques to minimize the lash. It should be stated that the lash is part of the normal operation of a motorcycle transmission and not an indication of a problem with the bike.
Causes
Triumph Street Triple Gearlash: http://www.youtube.com/watch?feature=player_embedded&v=yKlsInsP7r0
Empulse gearlash: http://www.youtube.com/watch?feature=player_embedded&v=9SZkPI4HUnU
Gearlash internals: http://www.youtube.com/watch?feature=player_embedded&v=mn2p_hYX0io
Remedies
Rollback
When the bike is stopped, push the bike back until you feel the transmission engage. Note that this will be about 6 inches (15 cm), and the feeling of the transmission will be very subtle. Engage the brake and you will be ready to start without any lash.
Dragging the brake
Similar to regular ICE bikes, dragging the rear brake when going a low speeds will prevent the transmission bounce.