We continue to prepare for our upcoming TransAm trip this coming summer (we hope). In doing this we are thinking about the bike (Cannondale RT3000 tandem). It is equipped with a 9 Spd triple crankset and an XTR cassette in the back. We're going to change our gearing up front so we have mucho granny capability and a lot less upper gear capability at the same time. We'd like to go from 30/42/52 to something like 22/32/44. The question is, it is possible to change our rings to this lower configuration, or are we forced to replace the Ultegra crankset with XT or XTR?