Even though this question is out of the time frame....

[Philippus Flavius Homovallumus]

As little as 5.5kg which is 12lb apparently.

[Baryonyx Walkeri]

Perhaps it was to expensive? anyway many tech were lost since the romans recruitted Barbarian units....

[Foot]

Well considering that it was the "barbarian" celts and peoples of the Iberian penisular that were the greatest metalsmiths in the west, I think that comment is a bit unfair.

Foot

[keravnos]

If you look at this,


depicting the Seleukid arms that were the trophy that Pergammon got out of the battle of Magnesia at 190 BCE.

Now the "lamellar tubes" worn in the hand and feet of the cataphracts do bear a big resemblance to the Lorica segmentata. I don't claim to know the exact chronology or hows' and whys' of lorica segmentata coming into production, but I must point out the similarities.

Another one, found in the armory of presumably, "Alexandria Oxiane" or Ai Khanoum (destroyed at 145 BCE) as it is presently known is the following...

pair of shoulder-pieces, found positioned one on the other, each of them being composed of three parts: a completion of lanceolate scales protecting the shoulder-blade, four rectangular lamellae covering transversally the shoulder top and an oblong plate provided with a buckle permitting the attachment to the corselet

If I had to guess, knowing that the Sakae had become masters in heavy cavalry and horse barding and using lamellae on those as well, the Eastern Hellenes, Seleukides and Baktrians were heavily influenced by those.

I don't know the specifics here but there should be some connection between those and


and please excuse me for saying this again, but...

LORICA SEGMENTATA IS OUT OF OUR TIMELINE!

[Philippus Flavius Homovallumus]

Perhaps it was to expensive? anyway many tech were lost since the romans recruitted Barbarian units....

That is a common misconceeption which is basically wrong. From the early principate onwards over 50% of the army and more of the marines and navy were "barbarian" non-citizens, the auxillary infantry and other service branches were excellent at Romanising their recruits and this is not why technology or fighting tactics degenerated.

Further, Lorica Segmentata was produced by Gallic or Germanic smiths in the Rhineland, actual Roman metal working was generally poor by comparison.

The reason it was dropped was because it was expesive, difficult to maintain and manufacture, not to mention providing overall lower protection than hamata.

[O'ETAIPOS]

Perhaps it was to expensive? anyway many tech were lost since the romans recruitted Barbarian units....

Tech were lost later, during wars of III-VI centuries that left a lot of regions in ruins, we should also remember that Great Desease in the end of II century destabilised all economy (and trus production) of Roman Empire.

[Philippus Flavius Homovallumus]

Far more important though were the wars themselves and the fact that the nessecitated Legions spending much longer in the field, being re-deployed and moved from bases they had occupied for more than two centuries. Rather like an SA80 LS is fine in barracks but on the march it is an unpleasent and potentially life threatening headache.