The Amira came about because semi pro and pro riders where finding the back end of the Ruby too flexible for their power out put.

My friend, who after coming 11th fastest woman in a 160km event (with over 10,000 riders) decided to get serious. She got a Ruby but found that the power output she had make the rear end "wag" when she dropped the hammer.

OK so who is the Amira designed for? Someone who is truly racing, like crits, road races etc who is averaging 35km/hr+ speed wise and is doing national road races etc looking for gaining places in professional teams, national cycle teams etc. Take a look at the rear stays of the Amira- they are so much thicker than the Ruby and the head tube is lower to be more aerodynamic. That is not to say that someone else cannot ride this bike- if the fit works best for you, buy it. Just that the Amira is designed with a different purpose to the Ruby.