thanks for all the info KiWi. My Ruby is a 2007 wish was pretty compatible to my 2005 Dolce which I had sold. All including my my new Dolce are 51's. I think they made the 2011 Dolce's much more relaxed as I am sitting more upright on it. This is all fine because each bike will have a different purpose and comfortwise are good for each bikes purpose if that makes any sense.