I use a 36 from King's and a tuned pipe from Sick bike parts so it gets a lot more low end power to make up for the loss. Go's much faster now (38.9 on the flat).
The only real problem is that I don't get any real exercise, so I have to ride my trainer inside (boring) but safe. Otherwise I will plump up like the Pillsbury dow boy.
Mike -live to ride, ride to eat-Frye