Another video with 'silencers' added to the Muskethttp://www.youtube.com/watch?NR=1&v=VmgQ-JYIN4c&feature=endscreenNot quite sure what the thunk sound is but it seems to go away when the engine is reved a bit.I looked for a follow up video that would show the bike on the road with its silencers installed but I wasn't successful.