Thanks a million for all your advice and thank you Greg for doing all the research, development, and then the actual modification...Just got back from taking the bike out for a 2 1/2 hour ride and it is like a new bike - the bike seat can get low enough now that there's no knee strain, the seat is solidly locked into position, can be adjusted as needed - the Stoker, absolutely loves it, loves the feeling of being able to move freely and to chat within hearing range while we are cycling - gear changing, brakes, and steering had become too much on the recumbent trike, now by working together on the tandem we are back cycling as a team. Thank you so much Greg for taking on the modifications and for everyone in this forum for your advice. Happy Cycling!!