Shimano has introduced the new 7900 Dura Ace group set with a weight saving of 135 g over the older 7800 model. The new Shimano 7900 Groupset looks very professional with its black and silver hi-tech image. The main changes to the Dura Ace 7900 groupset from the 7800 are:

The Dura-Ace Hollowtech II Crankset comes in a standard or compact design and is 20% stiffer than 7800 series crank. The Shimano Hollowtech II cranks are retain from the earlier Dura Ace model as they add rigidity and are light weigh. However the chain ring teeth have been re-profiled for a more efficient chain contact and power transfermation. The Shimano 7900 Dura Ace Hollowtech II Crank set is 15 g lighter than the older 7800 model. The bottom bracket seals have been improved to reduce bearing contamination and seal friction to give a combined weight including the bottom bracket of 725 g (170 mm crank model)

The Shimano Dura Ace Dual Control Levers (STi's) have under gone major changes from the 7800 model. The new 7900 model deatures unidirectional carbon fiber lever blades that reduce weight without loss of durability, they also come with a Titanium clamp and fixing bolt. The Dura Ace 7900 STi;s have a new perch shape that is thought to be more comfortable over longer distances. Another feature is the integrated reach adjuster that provides a custom fit for even smaller hands. On the Dura Ace 7900 models the external cable is now a thing of the past with an internal shifter mechanism that allows for hidden cable routing without increased friction. The rear shift stroke has been reduced by 20% for faster rear shifts and a revised brake cable pivot location provides better braking modulation. The Dura Ace 7900 STi's are 40 g lighter than the 7800 series and are FlightDeck ready with wireless integration and built in buttons to give a total weight if 378 g.

Shimano 7900 Dura Ace Hyperglide 10-speed Chain with new Quicklink Asymmetrical design allows the inner and outer plates to be optimized for front and rear drive shifting performance. The outer plates are designed to help reduce chain suck on the chainrings whilst the inner plates are designed to enhance the interface with the cogset for efficient power transfer. The 7900 chain comes with hollow pins for lighter weight and the new link designs improve drivetrain smoothness whilst reducing noise. The 7800 10-speed Hyperglide connecting pin can still be used if required. The new Dura Ace 7900 chain offers an 18 gram weight savings over the 7800 model and totals 252 g

The groupset also consists of cassette, brakes, front and rear changer.