Originally Posted by Barrettscv

If the OE crank is a Sram road compact, as is your Apex, than an Ultegra triple crank will fit. You will need a matching Hollowtech II bottom bracket. You will need Shimano Triple front and rear derailleurs, your Sram derailleurs are not Shimano compatible. Shimano 6603, 6703, 5603 , 5703, and 4603 are compatible with your Ultegra triple shifters. If you want to keep your 12-36 cassette, you will need a 9 speed Deore rear derailleur such as the one seen here. Stay clear of Deore Dyna-sys, these will not work with you shifters.

Shimano XT RD-M772 Shadow SGS Rear Derailleur Top Normal - Harris Cyclery bicycle shop - West Newton, Massachusetts