Technique

On test: Shimano Dura Ace 7900

Details

Parent Category: Technique

Category: Shimano

Published on Wednesday, 30 June 2010 08:22

Written by Luca Salvatelli

High quality materials, finishes and features

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The Shimano Dura Ace has been completely renovated last year and remains one of the landmarks of the area, coveted by fans, although not widespread because of a price even if its content aligned to direct competitors. So it is much easier to see the bike assembled with 6700 Ultegra group is much more rare to notice a bike with Dura Ace 7900 group. The new group is recognized immediately for the internal cable, a novelty, but all members of the group were revised and developed. The new commands have been completely redesigned, now have a new ergonomic, more compact carbon brakes levers, adjustable in the distance and with a new ergonomic profile. The mounting clamps are made of titanium, while the excursion was reduced levers for passage of the report. They have a declared weight of 379 grams. Also revised rear derailleur, with the introduction of different carbon fiber components. Parallelogram again, lighter and stiffer to ensure greater accuracy changed. The derailleur can be compatible with the adoption of sprockets with 28 teeth and with traditional toppings or compact. He said a weight of 166 grams. Even the front derailleur now has a more rigid and a different geometry to provide passes report faster. He said a weight of 67 grams. The crankset has remained faithful to the aluminum alloy for its realization. Now is produced by forging to improve weight and stiffness. New type of attachment of crowns, now integrated type to ensure better rigidity crowns/cranks. These the available options: 53-42, 54-42, 53-39, 52-39, 55-52, 56-44, 50-34. The cranks can have a length of 165, 167.5, 170, 172.5, 175, 177.5, 180 mm. The bottom bracket bearings, slides and more rigid than the previous version are also available with the standard BB30. He said a weight of 725 grams including bottom bracket. The cassette cogs have a new set of combinations, but especially new profiles to facilitate the passage of the report, and cogs in the last four reports, in titanium, while the others are steel. The combinations available are: 11-21, 11-23, 11-25, 11-27, 11-28, 12-23, 12-25, 12-27. It has a declared weight, as 11-23, of 163 grams. The chain is assembled without tools and has pins and perforated mesh. Has a different profile on the inside and outside to improve the slope on the front and rear ratios. Lighter and stiffer the old model. He said a weight of 252 grams to 114 mesh. Even the brakes have been revised, the arms are forged for greater rigidity and have titanium pins. And mind the possibility to adjust the voltage of closing and opening of the body and is newly designed brake lever for the rapid opening of the brake assembly. Revised rear brake cable routing to reduce friction and improve response to the command. New friction material, which provides better brake power (20%) and especially in the wet (50%). They have a declared weight of 293 grams. Also in the group are the Dura Ace hubs, wheels and pedals.

The road test

The Dura Ace group has always been a reference point for its construction quality and the model 7900, confirms the validity of a perfect realization. The beautiful forged aluminum crankset, charm well over carbon models, also perfect brakes and their surface treatment, as well as the realization of the exchange and controls. They are also more compact and aesthetically modern. Their ergonomics is perfect, very comfortable, you are challenging well with both large and small hands and levers are the right distance, ready to be operated, the high possibility of adjusting the distance between them. The fluidity of action of the shift levers and front derailleur is more than excellent, and though no more than old Dura Ace is the best in its class. The hike of the same levers to move the ratio is average, a bit wider than the SRAM Red, but still good and comparable to that of the Campagnolo Record. More than good gear changing, though less than SRAM Red and the Campagnolo Record, but also remained unchanged in the flow passages of the report, the quietness and precision all elements that do remain at the top of this group Dura Ace 7900. The braking force is more than good with a powerful front brake and adjustable rear like that. In this respect the Dura Ace is exactly half way between the SRAM Red with a more powerful braking system, but less adaptable, and Campagnolo Record rear brake in the less powerful but more adaptable, even in the front brake. However, in absolute terms, the braking force and its scalability is very good and able to satisfy even the most demanding athletes. Excellent performance of the braking in the wet. Perfect rigidity of the crank and its smoothness, the level of the best products on the market. Good, then, the wide range of reports available and the wide range of crank lengths available. Finally a group of high level design features a high and perfect operation, with unique features that make it more competitive and successful in many respects than the competition. The only fault is that it was not, the absolute minimum weight, preferring to focus on other aspects such as reliability and functionality. A suitable group of agony, but even more amateurs for its high build quality, reliability, longevity and security. A group perfect for a high-level bike, which is not surprising for its weight, but its high overall quality. On offer the complete set is about 1149 Euros, lower than its competitors Sram and Campagnolo, and more than good.

Positive aspects

Build quality
Ergonomic controls
Accuracy and noise in the steps of relationship
Braking power and modulation
Rigidity of the crank
Reliability

Negative aspects

Weight

To learn more:

Shimano
Website: www.shimano.com