Not used the ribbon myself, but just had a look.
I opened TC as a blank file, went into workspace customise, Toolbars, and clicked New (to create a blank toolbar), I called it MeasureIt. I could then add the measurement tools from the commands page of the dialog to this new toolbar. Click close, then re-open the customise dialog, and the new toolbar should be available under the pop-up section. After that I had to save the blank file before the new toolbar would stick, so it would be available after TC was closed and re-opened.