Hi All,
Thanks for the replies. I will jack the bike up and see what the deal is with this noise. The more I think of it, the more I think it is a warped disc. Using the front brakes, I can feel the disc grabbing a little harder, but have no feedback through the brake lever. I guess it wouldn't have to be much though to feel it. I was hoping it was just something greasy on the disc that may come off with brake cleaner but everything seems to be pointing to the discs at the moment, that's for sure.
rkt88, thanks for the offer, however I am a really terrible swimmer!