In one of my books, it talks about ideal cadences for different types of cycling ... just a moment ... let me see if I've got that book within arm's reach .... OK, I don't seem to have that one right here, however, what it said basically was this:
New cyclists generally ride with a cadence of <70 rpm
Endurance cyclists (and possibly also Time Trialists) ride with a cadence of somewhere between about 85 and 95 rpm
Racers ride with a cadence of >100 rmp.
Another book I have here (Bicycle Medicine) also indicates that the optimum cadence for endurance is fairly low (in the 80-85 rpm range).
As it happens my cadence is 85 rpm ... and that seems just about right for me!
BTW - I thought you'd vanished from the forums for a bit there ... I hope you are healing well.