The 2009 7900 Series Dura Ace road racing group set made by Shimano is 135 grams (4.76 ounces) lighter than Dura Ace 7800 and provides more of a black and silver hi-tech look. Dura Ace 2009 (even though we are still in the year 2008) ups the ante on cycling component choice, performance, and value. The FC-7900 HollowTech crankset is 20 percent stiffer and has re-profiled teeth. The new crankset has hollow chain rings and is available in 53T/39T, 52T/39T, 52T/42T, 54T/42T, 55T/42T, and 56T/44T configurations. So, you are bound to find a chain ring combination that makes your body and need for speed happy. Not doing a ton of racing but want high-performance in a compact crankset? The Dura Ace 7900 Series offers a compact crankset (FC-7950) with 50T/34T chain rings. In addition, you shorter- and longer-legged beasts on two wheels, can order cranks lengths from 165mm to 180mm in 2.5mm increments.
Here are a few Dura Ace 7900 details. (Jump for more details): The ST-7900 Dura Ace Dual Control Levers have titanium fixing bolts. Shimano engineers have decreased the rear shift stroke by 20 percent for faster rear shifts, and they have shaved 40 grams of weight from each pair. The CS-7900 cassette, with an aluminum carrier and the four largest sprockets made of titanium, is offered in 11-21T, 11-23T, 11-25T, 11-27T, 11-28T, 12-23T, 12-25T, 12-27T. Again, you should be able to find the right cassette for your cycling preferences and geography. The RD-7900 rear derailleur has a carbon pulley plate. The FD-7900-B front derailleur has been redesigned to eliminate trim (having to click your shifter between the settings in certain gear ratios, so the chain doesn't rub). The BR-7900 brake calipers have a redesigned brake arch. The PD-7810 Pro-Tour Racing pedals, released a while ago, have an extra-wide platform. The FH-7900 rear hub (8-, 9-, and 10-speed compatible) has a titanium free hub body.
The 7900 series wheel sets are offered in six flavors. You may choose to race on a carbon 50mm high-profile tubular or clincher wheel set: WH-7850-C50-TU at 1467 gms, and WH-7850-C50-CL at 1580 gms. Need something less aero and lighter? Check out the 7900 series carbon tubular and tubeless wheel sets: WH-7850-C24-TU at 1257 gms and WH-7850-C24-TL at 1400 gms. Or you can opt for a even lighter carbon alloy composite clincher wheel set: WH-7850-C24-CL at 1380 gms or a Scandium road tubeless wheel set: WH7850-SL at 1514 gms. (All weights given are for a pair of wheels.)
For many talented but disorganized cycling cats, your chain repair tool of choice is your cellphone, which you dial to get a ride home when your chain breaks. These cats, and those mileage monsters who have forgotten to re-stock the chain pin supply in their seat bags, may be quite happy about the CN-7900 Dura Ace Hyperglide 10-speed chain. In addition to having hollow pins and perforated chain plates, it can accept the new and reusable Quicklink connector. (Time will tell if it this is a good idea.) According to Shimano, you can use a new SM-CN79 Quicklink reusable connection link for tool-free chain removal and installation on the CN-7900 chain, and you can still use a 10-speed Hyperglide connecting pin to connect the chain.
I really like the smooth feeling of the 7800 Dura Ace road chains, so if you are riding a new Dura Ace CN-7900 chain with or without the Quicklink, please put up a post, and let us know if the redesigned chain feels markedly smoother. If you have first-hand experience fixing a busted Dura Ace 7900 chain without using tools leave a comment. Actually, if you are riding any of these new 7900 Dura Ace Series group set parts, put up a post and let us know how they compare to Dura Ace 7800.
(Jump for more 2009 Dura Ace 7900 Series road racing group set performance stats and specs and check out Shimano's Dura Ace website.)
(Photos lifted from the Shimano Dura Ace website.)
Here are more details about the Dura Ace 7900 Series road bike group set taken from the Shimano press release:
FC-7900 Dura-Ace Hollowtech II Crankset
Std or Compact
- 20% stiffer than 7800 series crank
- Hollowtech II hollow forged arms
- Hollow chainring construction for added rigidity and light weigh
- Re-profiled chainring teeth for more efficient chain contact and power transfer
- Available in FC-7950 compact gearing (50/34)
- Lengths available: 165 -180mm in 2.5mm increments
- Ratios available: 53/39, 52/39, 52/42, 54/42, 55/42, 56/44
- 15 grams lighter than 7800 series
- Bottom bracket seals improved to reduce bearing contamination and seal friction
- 725g (170mm) including bottom bracket
ST-7900 Dura Ace Dual Control Levers
- Unidirectional carbon fiber lever blades reduce weight without loss of durability
- Titanium clamp and fixing bolt
- New perch shape is more comfortable over longer distances
- Integrated reach adjuster provides a custom fit for even smaller hands
- Redesign internal shifter mechanism allows for hidden cable routing without increased friction
- Rear shift stroke reduced by 20% for faster rear shifts
- Revised brake cable pivot location provides better braking modulation
- 40 gram weight savings per pair over 7800 series
- FlightDeck ready with wireless integration and built in buttons 378g
CN-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
- Outer plates designed to help reduce chain suck on the chainrings
- Inner plates designed to enhance the interface with the cogset for efficient power transfer
- Hollow pins for lighter weight
- New link designs improve drivetrain smoothness and reduce noise
- Uses new SM-CN79 quicklink reusable connection link for tool-free chain removal and installation
- Can still use 10-speed Hyperglide connecting pin
- 18 gram weight savings over 7800 series 252g
