dave s, Because the Ultegra 6500 group used a short production span BB model, no matter what compact crank set you find, it'll most likely require a new BB just as a triple would. I thought there was a compact that used the Octalink V1 BB, but looks like I was wrong as I can't find one now.

Find a something-34T cassette and a XT RD, same level as Ultegra, to modify the rear. A new chain is also probably required.

Brad