Shimano Dura-Ace Part 2 (7900)

Shimano Dura-Ace Part 2 (7900)

Dura-Ace 7900
How does Shimano push the envelope when the cycling community is just getting up to speed with its last Dura-Ace components? Shimano’s 7900 begins with a new hollow chainring design with a carbon shifting assist profile. The derailleur cables are tucked into the STI Dual Control lever bodies and their shifting action is double speed. The leverage ratio of the brakes is reconfigured, along with the brakepads, to boost modulation and match wet and dry weather stopping. Carbon fiber replaces aluminum in the rear derailleur’s pulley cage, and the world’s fastest-shifting front derailleur is reconfigured to eliminate micro adjustments at extreme chain angles. The 2009 topper? An asymmetric chain that is profiled on the inside link plates to better engage the next larger cogs.

Styled like nothing that came before it, Shimano’s Dura-Ace 7900 group may well be the “Swiss Watch” of the Dura-Ace legacy. It’s mechanical precision is certainly comparable- especially if one has the courage to disassemble the inner workings of its STI dual-action levers-but Shimano’s Di2 replaces the complicated mechanical innards of 7900 with simple (and reliable) electronics. Will Di2 overshadow Dura-Ace STI levers like the electronic quartz movement overwhelmed the self-winding mechanical watch?

(www.roadbikeaction.com)

 

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