Dura-Ace

Dura-Ace is a group of bicycle components from the Japanese manufacturer Shimano . It is the highest quality racing bike group from Shimano and is offered both in a version with mechanical shifting and in a version with electromechanical shifting (Di2).

11-speed Dura-Ace STI shifter (9100 series)

Development over time

The market launch of the group dates back to 1973 and was intended to secure market shares in the field of high-quality racing bikes for the manufacturer , which was then mainly represented in the middle class of the bicycle industry . At that time, this area was only served by Campagnolo .

While the initial phase in the 1970s was characterized by imitating the Record group of the Italian market leader Campagnolo , in-house innovations were increasingly used from the early 1980s.

The Dura-Ace AX presented in 1980 appeared revolutionary, with its aerodynamic design sparking a trend in the racing bike industry and inspiring other manufacturers in this sector to revise their products accordingly. Suntour brought the Sprint and Cyclone racing bike series onto the market, following the trend towards aerodynamics.

For road racing (the Dura-Ace also offers a track bike version in a smaller edition ), the group was completely redesigned for the fifth time in autumn 2003.

An electronic Dura-Ace group (the Di2), in which the shifting operations on the derailleur and rear derailleur are carried out by an electric servo motor, was released in 2009. In addition, a completely revised mechanical Dura-Ace complete group with a modified design and reduced weight (carbon crank and carbon shift levers) has been available since 2009.

Delimitable generations

1st generation

Crane rear derailleur on a Puch racing bike

In 1973 Shimano equipped the European Flandria racing team with the new components. These consisted of frame shift levers without indexing for rear derailleurs with 5 or 6 gears. Pinions were available either as a freewheel with freewheel hubs or individually for attachment to freewheel hubs.

The freewheel hubs were a trend-setting innovation back then. The first generation of the Dura-Ace freewheel already had a level difference between the inside diameter of the inserted pinion and the screwed final pinion. This and the direct screw connection to the hub body via a special thread separated the Dura-Ace freewheel hub from other Shimano freewheel hubs until 1997.

Furthermore, a found themselves in this generation Tretkurbelsatz including cone bottom bracket with square shaft, a tax rate and rim brakes including brake lever and a seat post again. Back then, Shimano offered Dura-Ace dropouts for frame and fork to frame builders. Pedals did not belong to the first generation group.

The first rear derailleur was a special feature. It was labeled Crane.

As part of the facelift, the bolt circle diameter of the crankset was reduced to the current 130 mm. The rear derailleur has the Dura-Ace logo and seals on the hinge pins.

In 1978 the Dura Ace EX was introduced, which with its split back plate enables the chain to be removed quickly from the rear derailleur. The EX later got some of the innovations of the Dura-Ace AX from Generation 2.

2nd generation

Shimano DuraAce rear derailleur

In 1980 a lot changed for the group. Except for the sprocket and chain , all components have been adapted. The aerodynamic shape is evident at first glance. The AX introduced a stem, handlebars, an aerodynamic drinking bottle with bottle holder and completely new pedals in addition to the bicycle parts already in the group. The pedals were screwed into a 1 inch pedal thread in the cranks and did not have a continuous pedal axis. At that time, the advantage was seen in the driver's lower position on the pedals, which improved aerodynamics.

An innovation of this group, the brake cables routed to the handlebars, was withdrawn from the successor, although it has meanwhile established itself with all manufacturers.

3rd generation

In 1984 Shimano offered the Dura-Ace New. This was designed very classically and not provided with any noticeable innovations even in the early stages. In the 13 years of their market presence, Shimano was able to earn a place next to Campagnolo. Innovations in the facelift such as eighth gear, gear shifting aids on pinions and chainrings, and clipless pedals were incorporated into this group.

4th generation

Dura-Ace rear derailleur (model RD-7700)

In 1984 Shimano introduced the 7400 series. In 1989/90 the world first followed, the newly developed brake / shift lever (“Shimano Total Integration” STI). In the mid-1990s, 9th gear was introduced in another series.

5th generation

The DuraAce 7800 series represent the new generation of components. The drive unit has been expanded to 10 gears, the bottom bracket is external (Hollowtech II) and the STI shifters are ergonomically shaped. In later models of the generation, they lead both the brake and shift cables along the handlebars. Later models were called the 7900 series with internally routed shift cables and carbon levers.
The current standard is now the Dura-Ace 9100 group with 11-fold switching units.