New Dura-Ace 7900  A legend sharpened to a new level of perfection. Providing the ideal symbiosis of lightweight, stiffness and performance. And finally out there to set new standards in professional cycling. The DURA-ACE 7900 series sets a new benchmark in top-level road racing components. Shimano has combined all its engineering resources with the latest technology to realize an increasing level of perfection that will benefit professional riders as well as many road-racing enthusiasts. Check out the products. roadbikereview.com  STI Levers and FlightDeck The 7900 STI levers get a completely different look and feel. Very significant is Shimano's first 'under bar tape' cable routing, with friction being kept to a minimum with a new PTFE coated inner cable. The lever blades are made of carbon and feature a reach adjust mechanism – ideal for people with smaller hands and a shorter reach. Shifting stroke is also reduced by 20% for faster shifts. The shifters also feature integrated buttons to operate the new wireless FlightDeck computer with the need to take the hands off the handlebar. The new FlightDeck system will measure data such as heart rate, altitude, inclination, cadence, gear position and more. It works via a coded signal to prevent cross talk and interference, and is also PC downloadable. (We will have to wait and see about Mac compatibility) With the help of a titanium fixing bolt and band the new STI levers come in at 50g lighter than the current 7800 version at 370g per pair. New bar-end shifters and down tube shifters will also be available to match the new 7900 groupset and a full carbon bar-end brake lever for aero bar setups will also be available.  Chains CN-7900 In Stock $70 The new CN-7900 chain features a re-useable quicklink (SM-CN79) that can be connected and disconnected without the need for tools. A directional chain is also pretty revolutionary by current standards, enabling the outer plates to be designed specifically to interact with the chainrings and the inner plates to work with cassette sprockets. Overall the results should be an even slicker shift than the current drive train, and quieter running. The chain has also been developed with hollow pins and perforated inner plates to help make it lighter – weight of the 7900 chain stands at 251g making it 20g lighter.  Cranksets FC-7900 FC-7950 This aerodynamically designed crankset combines new engineering features together with remarkable weight saving. High rigidity for optimal power transfer. 53-42T, 54-42T, 52-39T, 55-42T, 53-39T, 56-44T (Standard) 50-34T (Compact)  The rear derailleur is designed to be compatible with 28T cassette sprockets so one mech can cope with the entire range and is also compatible with compact chainset (FC-7950). A full carbon pulley wheel plate helps reduce weight to 166g.  The front derailleur has lower spring tension and leverage ratio, to work specifically with the new ST-7900 levers, for lighter action shifting. Trimming the mech when it is on the outer chainring position is no longer necessary thanks to a redesigned cage. Weight is only 68g.  Shifting has been even further improved by creating an even more rigid (and lighter) aluminum carrier unit along with re-engineered teeth profile. Cassette design is lighter as Shimano has developed a super lightweight and rigid aluminum cassette sprocket carrier. The largest four cogs are titanium and weight is reduced by 10 grams. Available combinations will be: 11-21T, 11-23T, 11-25T, 11-27T, 11-28T, 12-23T, 12-25T, 12-27T.  Brakes BR-7900 The new brakes have an enhanced brake arch, increasing the linear response and making them even more powerful than the already impressive 7800 brakes, with more modulation too. A lower cable clamp ensures better cable routing and reduced friction. The Dual-Pivot design has titanium hardware to get the weight down to 287g a pair. Also new is an improved brake pad compound, which sounds too good to be true, boasting twice as good stopping power in the wet, 20% improvement in the dry, and overall up to 50% less wear. |
