With all the talk of radial this and radial that, I had no idea what people were talking about. So, I upgraded my grey matter. Click here (the tech articles on the right hand side are a good read as well)

After Christmas, we learn about radial master cylinders

 

All it means really is that the arrangement of the caliper is in a radius, like the old airplanes Radial Engine, that is also the same for the master cylinder setup around the handle bar.