I have a Giant Rapid 2 ( 2010) with an FSA OMEGA TRIPLE MEGAEXO crank set with an FSA external bottom bracket, chainline 46mm. I want to install a Shimano UN55 Square Taper Bottom Bracket with a FSA Vero Square Taper Triple Chainset 9sp crank set. The BB comes in a range of spindle lengths 107, 110, 113, 115, 118, 122.5, 127mm. Would anybody know which spindle length that I need ?. I checked the existing spindle but no markings on it. I can't measure it as the drive crank is fixed to the spindle. Any help appreciated ?.