Need help on bike size!!!

[mountainpics]

Wait... if she felt too upright on the 54cm, a SHORTER top tube is going to make her feel even more upright. Of course, 5mm is within range to reasonably correct with a longer stem, but you should think twice about putting her on a smaller frame if she feels too upright on the 54...

I think she felt too upright on the Trek because the head tube was 15.5 cm (compared to 14 on the Diva) AND the stem on the Trek had a significant rise. You're right about a smaller top tube giving a more upright ride, but 5mm shorter won't make much difference, although the shorter head tube and no or negative rise stem will make a big difference, so I think I'll be ok.

[aicabsolut]

I think she felt too upright on the Trek because the head tube was 15.5 cm (compared to 14 on the Diva) AND the stem on the Trek had a significant rise. You're right about a smaller top tube giving a more upright ride, but 5mm shorter won't make much difference, although the shorter head tube and no or negative rise stem will make a big difference, so I think I'll be ok.

1.5 cm difference in head tube height plus different stem adjustment sounds right to me, even with .5cm difference in TT length. Congrats (to your girlfriend) on her new ride!