I did this on my road bike (3 x 9) when I changed from drop bars to "trekking" bars to help with arthritis in my wrist. I was able to make a direct substitution of an XTR shifter for the rear, replacing an Ultegra shifter. However, the XTR front shifter would not work with the derailleur, so I got a friction "Silver Shifter" from Rivendell. It works very well on the triple.