Nick,. .. .Thanks for the remarks.. .. .The study of rotor head configurations is certainly interesting. There would appear to be a correlation between phase lag and rotor control. A simple teetering rotor will have a 90-degree phase lag and a delayed control. At the other 'hypothetical' extreme, an absolutely rigid rotor will have a 0-degree phase lag and instantaneous control.. .. .As you have said, nothing is free; with greater control comes greater weight. . .______________ . .. .I want to look deeper into a low level of 'hub spring' on the SynchroLite. It may reduce the phase lag slightly, but what the heck, the hub already has delta-3 playing with the phase lag. What's one more factor. <img border="0" title="" alt="[Smile]" src="smile.gif" />. . . . <small>[ 12 March 2002, 07:28: Message edited by: Dave Jackson ]</small>