Shimano Dura-Ace 7900 [en]

Let’s have a look some minutes at the news featured with this high end new generation groupset:

The complete 7900 groupset:

The weight of the complete groupset is 2044g.

The crankset

Shimano still doesn’t switch to a carbon crankset. According to the japanese manufacturer, the only way to make the best lightness to stiffness ratio crankset is to use aluminium. The
carbon prototypes we spotted during the last few months won’t see the light before some time.

Briefly, from a technical point of view, the features concern the chainring which is hollow, and the hollow crankarms whose thicknesses have been optimized. Shimano claims a nice 20% extra
stiffness, and 50g are saved from the 7800 model, meaning 690g per crankset.

Those cranks will be available in compact and standard.

Regarding the aesthetics, this component looks quite good. The slender lines and the double color, although looking a bit weird at the first look, finally is pretty.

The transmission

The derailleurs

The derailleurs are completely redesigned. Their lines are matching the crank arms and the rear one even is featuring a carbon rear mech. The technical modifications concern the following
points: the rear derailleur accepts up to 28 teeth cogs, the front one is equipped with a softer spring to reduce the force required to shift, and finally, there is no need to trim anymore
thanks to a better geometry.

On the scale, the rear is about 166g, the front one is 68g, which are respectively 16g and 6g shaved off from the 7800 version.

The levers

We do not have a lot of things to add about the levers: they are indeed made out of carbon, the cable housings will pass under the bartape, either in front of the bars, either behind as
presented in the article we published in May. Beside this, the ergonomy is completely renewed.
The distance required to shift is reduced of 20% and the Flight Deck comptuters are totally wireless (i.e
article published the 16 of March). The weight saved from the 7800 shifters is 50g.

In term of look, the levers are quite flashy: half black, half silver, they match the derailleurs and the crankset but the shades look rough, they probably deserved more.

The chain

The chain of the Dura-Ace 7900 groupset is redesigned: the plates’ contact with teeth is improved to reduce friction and noise at the same time. Shimano claims a better durability too.
Last but not least, this new chain is featuring a brand new removable master link to disassemble and reinstall the chain as many times as needed… this is what « forced » us to use a SRAM,
KMC or Wipperman chain on the long term! This is probably the best upgrade on a groupset ever.
This chain is saving 18g over the former one.

The brakes

Weight save and power rise have to be expected here too: the new compounds bring 20% more braking power on dry conditions, and 100% more under the rain! Moreover, the levers geometries are
different and allow a better response contributing to the better braking performances.

More information: Dura-Ace