Originally Posted by
rms13
To be fair OP never mentioned anything about comfort other than asking if carbon, alum or titanium bars would be more comfortable than another.
But seriously, Pacer with 105 is a nice bike. If OP wants flat bars I would sell that bike and buy a hybrid. Probably get enough in the sale of the Pacer to pay for a decent hybrid as they are cheaper than road bikes
I admit I did infer from his question about the comfort of different bar materials that the driving force for the conversion would be to make the bike more comfortable to ride.
Which, in the absence of geometry changes, it probably won't. In fact, there's a good chance the loss of multiple hand positions on the current drop bars will make the bike less comfortable.