I am selling a new Velo Orange Framebag by Revelate Designs. It has been designed to fit VO Piolet Campeur etc. It will probably fit other medium road and some (older?) mountain bike frames. I am guessing 52cm 54cm (or maybe even 56cm top tube frames of more "traditional" no radically sloping top tubes) geometry will work best. (Someone told me it fits 56cm Wolverine quite well).

Here are the dimensions:
Length 18
Height 13.5
DT Length 20.5
they are pretty similar to current Revelate Ripio (Med) bag