Roman Cavalry

[jvrjenivs]

First, I would suggest you to have a look to the 'cavalry topic' in the re-enactment and reconstruction area. About all Cavalry re-enactors on RAT are discussing all kind of things in there. link from old RAT

For you answer about lorica. I don't know of any evidence for segmentata on horseback. I would go for either a hamata (chain) or sqamata (scale) in your timeframe.

Some sources that you can find interesting:
Karen R. Dixon & Pat Southern – The Roman Cavalry
Markus Junkelmann – Die Reiter Roms I, II, III
Markus Junkelmann – Reiter wie Statuen aus Erz
I.P. Stephenson & K.R. Dixon – Roman Cavalry Equipment

Of course there is much more written on Roman cavalry, but this are some sources where also equipment is discussed.