More on 2009 Dura-Ace

Dual Control Levers:

• Both brake & derailleur cables will be routed underneath the bar tape
  
• Decreased (I've heard by 20%) right shift lever throw
  
• Increased cable pull so that, theoretically, the shifting will be less finicky
  
• Unidirectional or carbon weave levers? There's pictures of both out there, but I think that the production levers will be unidirectional carbon fiber, just don't hold me to it.
• Adjustable reach on the levers to accommodate more hand & bar combinations (this is especially good news for riders with smaller hands who currently struggle to reach the levers)
  
• Longer & more shapely levers will be easier for riders to reach while riding in the drops
• Wider & flatter brake hoods than those of the hook-like 7800s
  

However much the prospect of shifters with increased cable pull may excite you, please be aware that this means that the 7900 shifters & the derailleurs will not be compatible with 7800 & previous 10speed Dura-Ace shifters and derailleurs.


Crankset:

• The 7900 (53/39 with a 130bcd) will be standard gearing
  
• The 7950 will be the compact gearing crankset (34/50 with a 110bcd)
  
• The crankset will be an unbelievably light 725gm (this weight includes the bb)
  
• The Hollowtech chainrings are ooh la la! and Shimano has radically increased the ramping, pinning, and milling for quicker, cleaner shifting
• The new cranksets are said to be 20% stiffer than the 7800 cranks (which themselves were much stiffer than the previous Dura-Ace iterations)

Front Derailleur:

• Redesigned cage profile and linkage so that no trim will be required
  
• Shimano has reduced the spring tension on the front derailleur so that shifting forces needed to shift from the small ring to the big ring are decreased
  

Cassette:

• Aluminum cog carrier shaves off a little more weight
  
• Increase in available ratios (11-28, 11-27, etc.)
  
• Reshaped teeth & shift gates for better use with the new Super Narrow chain
  

Super Narrow Chain:

• Hollow pins & perforated plates is a first for Shimano
  
• The outside plates have been shaped to reduce potential chain suck
• The inside plates have been shaped and engineered to reduce drive train friction (this reduction in drive train friction is said to be "noticeable")
• A master-esque link (Whoo-hoo!)
  

Rear Derailleur:

• Carbon fiber pulley cage
• Reduction in weight by 16 gms
  
• The chain wrap capacity had to be increased to accommodate those of us who will use Shimano new compact crank with their new 11-28 cassette
• There is marked increased material at the rear derailleur pivots which should improve the stiffness (and therefore the shifting response) of the rear derailleur
  
• An added pin between the derailleur cage & the pulleys
  

Brakes:

• Radically machined brakes and modified brake arches for better braking performance
• Lower profile cable stop (for easier cable routing!)
• New brake pad materials for better overall braking performance and less wear while braking in the wet