You should review your application and reexamine if a Ribbon is appropriate for your application.
Ribbons are not meant to be used in parallel with menus and toolbars. The opening paragraphs to the Ribbons Guidelines:
Ribbons are the modern way to help users find, understand, and use commands efficiently and directly—with a minimum number of clicks, with less need to resort to trial-and-error, and without having to refer to Help.
A ribbon is a command bar that organizes a program's features into a series of tabs at the top of a window. Using a ribbon increases discoverability of features and functions, enables quicker learning of the program as a whole, and makes users feel more in control of their experience with the program. A ribbon can replace both the traditional menu bar and toolbars.
If you do not include everything in your Ribbon, where else do you intend to put it?
You can read more about why the Ribbon was developed here: The Story of the Ribbon, or watch Jensen Harris talk about it in this video.
If you watch the video, at 18-minutes Jensen begins to discuss Result Oriented Design which is the process behind the development of Ribbon.
For those who think the Ribbon is the worst thing ever: you can also check timestamp 1:10:00. Not to argue that it is great, but it isn't the worst thing to happen to a Microsoft product.
Without knowing the nature of your application we can't provide recommendations on if a Ribbon is the better choice over menus or tool bars. Knowing what the correct design pattern is for your application requires an understanding of your users and what your user needs are.
If you have not already, review all the design guidelines for Ribbon and how Microsoft recommends organizing the information within a Ribbon. Regardless of if you agree with Ribbons, Microsoft has put a great deal of thought into them and does have reasonable recommendations.