typically all Bianchis are measure C 2 T for the ST and C 2 C on the TT. what do you mean by "ETT"?
in general it appears that most Bianchi of 55cm frames have a 73' HT. depening on the model and year the TTs range from about 54.5 to 56 wich gives a ST of between 73' and 74'.
the CdI being in the performance class has the more relaxed ST while a Mondaile or TSX would be more aggresive being in the Professional class.
if you are comfortable standing over a 55cm with a horizontal TT I suggest getting that and using the stem to adjust your reach.
also not all models come in all three sizes, most will only be 55cm. normally only some Reparto Corse models come in 1cm incriments.
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