Click on the PDF below for a tech comparison between four, un-named carbon fibre crank sets and the 2003 Dura Ace crank arm (FC-7701).
The chart compares three factors: weight, torsional rigidity and bending rigidity.
Aluminium was the choice for the 2003 Dura Ace and, according to Shimano Japan's testing engineers, is still the material of choice for the 2004 crank arms.
"Our FC-7701 is slightly heavier, but offers a great advantage in terms of torsional and bending rigidity," said Aguilera.
"The new Dura Ace has been improved in terms of weight and rigidity, so the comparison tests are even better with the new Dura Ace (FC-7800)."