I read your post about using a 11/34 cassette and mountain bike Rd with your shimano durace shifters. Any chance you can provide me the model number of the RD? Also my shop told me that adding a mountain RD would work but I would not have access to all 10 gears? Is this true? How did this combo work out for you? I am getting ready to ride across US next year and I know I can't do the mountains with a dura ace 28 cassette?