What is the difference between Shimano Dura-Ace and Shimano Ultegra? Is Shimano’s flagship Dura-Ace component kit worth the additional cost over Shimano Ultegra? Exactly what are the differences between Dura-Ace and Ultegra and what do these differences mean to the consumer? How good is Shimano Ultegra?
These are good questions if you are deciding between a Shimano Dura-Ace and Shimano Ultegra equipped bike. Understanding the real differences between Ultegra and Dura-Ace is critical to know exactly what you are paying for. The answers are more surprising than you may imagine.
Shimano Dura-Ace 7900 Series for 2011 is Shimano’s highest-end component kit. It is the same kit that has won the Ford Ironman Triathlon World Championships and seven consecutive Tours de France on Lance Armstrong’s bike. When you consider Shimano’s market share versus Campagnolo and SRAM there is no doubt that, worldwide, Shimano Dura-Ace is the most winning component group on the planet.
Shimano Ultegra 6700 Series is the next level down from Dura-Ace in price and performance on the Shimano good/better/best continuum. Ultegra started life as the Shimano 600 component kit and has had several upgrades/updates including the introduction of new 2011 Shimano Ultegra 6700. Shimano Ultegra has no Tour de France wins to claim but likely has won several Ironmans and certainly has won scores of national and local class triathlons.
In our first installment comparing the two groups we focus on the heart of the groups: The front and rear derailleurs. These are the devices that move (or “derail”) the chain from gear to gear when you shift.
This is an important comparison since most triathlon bikes use Shimano Ultegra or Dura-Ace front and rear derailleurs, or a combination of the two, and go to other companies for the brakes, cranks, etc.
The quality of the shift you feel is delivered through the tactile interface between your hand and the shifter. Whether you are using a Shimano 105, Ultegra, Ultegra SL or Dura-Ace derailleur or a mix of those derailleurs you will be shifting with the same shifter. The shift will require the same distance of lever travel and feel the same through the lever. Because of this, it is very difficult for anyone to tell the difference between Shimano Ultegra and Shimano Dura-Ace shift quality when using bar end shifters. We interviewed two bicycle company product managers, three sales reps, two technical reps, several elite level amateur triathletes and one nine-time Tour de France finisher about the difference between Shimano Dura-Ace and Shimano Ultegra when using the bar end shifters and their response was unanimous: They each said they could not tell an Ultegra Rear derailleur from a Dura-Ace rear derailleur on shift quality using bar end shifters.
Greater factors in shifting performance will be how precisely the derailleur cable housings were cut to length and had their ends finished, what type of cable housings and ferrules was used and the cable routing on the bike frame. The cleaner the cable routing and the more precise the assembly job, the better the shifting. These factors make more difference in shift quality than does the difference between Ultegra and Dura-Ace.
Shimano Dura-Ace vs. Ultegra Rear Derailleurs.
For the purpose of our review we are discussing only short cage, or “SS” versions of rear derailleurs, not the touring long cage GS version as used on cyclocross, touring or triple equipped bikes.
The Shimano Ultegra (short cage) RD-6700 The Shimano Dura-Ace rear derailleur is the RD-7900-SS short cage rear derailleur. There is only one version of the short cage Dura-Ace rear derailleur.
The differences between the Dura-Ace and Ultegra rear derailleurs are:
The Dura-Ace rear derailleur weighs 180 grams and the Ultegra weighs 200 grams. These are actual product weights measured in our store, not taken from manufacturer’s reference. The Dura-Ace rear derailleur is 12.8% lighter than the Ultegra. This 20 gram weight difference is 4 grams shy of an ounce. As a basis for comparison an energy gel pack weighs 38 grams, so the difference in weight between these two rear derailleurs is significantly less than one energy gel pack.
The Dura-Ace rear derailleur is made by cold forging producing a more impact resistant and stiffer outer and inner link. The derailleur is anodized to produce its silver color and provide a durable finish. The benefit is the Dura-Ace rear derailleur will last longer under normal wear than Ultegra before it wears out and will survive impacts that may cause Ultegra to break.
This difference in durability is reflected in the warranties on the Ultegra rear derailleur as compared to Dura-Ace. As described on page 9, Paragraph 1 of the 2011 “Shimano Total Information” dealer reference manual, Ultegra is warranted “free for non-conformities in material and workmanship for a period of two years”. Dura-Ace is warranted for three years.
The Ultegra rear derailleur is also forged, but it is not cold forged. This difference means you can see rough-looking surfaces on the inside portions of the derailleur body. The standard forging process of Ultegra does not produce as durable a component as does the Dura-Ace cold-forging process.
The Dura-Ace rear derailleur is cold forged out of a high quality aluminum known as “Dura-Luminum” whereas the Ultegra is made of standard aluminum. Shimano would not disclose specifics of the differences in materials and bicycle company product managers did not know the differences between the two types of aluminum.
There are two small wheels on a rear derailleur, the upper wheel, known as the “Guide Pulley” and the lower wheel known as the “Tension Pulley”. Shimano achieves excellent shifting performance on both Dura-Ace and Ultegra by using a “Centeron Guide Pulley” with a small amount of side-to-side play that enables the guide pulley to center on the cassette cog more precisely. On Shimano Dura-Ace the upper guide pulley and lower tension pulley rotate on bearings. On the Ultegra rear derailleur the upper guide pulley rotates on a bushing and only the lower tension pulley rotates on bearings. This means both pulleys on Dura-Ace rotate on bearings for lower rotating resistance than the Ultegra which uses bushings and bearings on the guide pulley and tension pulley. No data is available on what the tangible differences in chain rotating resistance are between Ultegra and Dura-Ace.
The Dura-Ace rear derailleur uses a black polymer glide surface on the inside of the outer plate. This black polymer surface slides against the chain during upshifts as you are moving the chain up the cogset to the easier gears. This makes shifting quieter. This polymer surface also reduces friction between the guide plate and the chain during upshifts. This feature accounts for the quieter shifting with a Dura-Ace rear derailleur as compared to Ultegra. Shift speed and shift repeatability between Ultegra and Dura-Ace rear derailleurs are the same.
There are four link pins that hold the entire derailleur body together on both Ultegra and Dura-Ace. These are the pins upon which the entire derailleur body moves in and out while shifting. The four link pins on the Dura-Ace derailleur are fluorine coated. This coating insures the pins will stay in place longer and they move more freely in the Dura-Ace rear derailleur.
When you closely examine a Dura-Ace rear derailleur in comparison to Ultegra you see some interesting differences. Looking from the back the rear link on Shimano Dura-Ace is black in color and has a large hole in it for weight savings. The armature of the inner link is mounted outside the upper body of the derailleur for a stiffer, wider mounting to the upper body. The inner link on Ultegra rides inside the lower body of the derailleur.
The limit screws on the Shimano Dura-Ace rear derailleur are recessed and therefore protected from damage by impact. On Ultegra these upper and lower limit screws protrude outside the upper body of the derailleur.
The general shape of the two derailleurs as viewed from behind the barrel adjusters is also different. The barrel adjuster on Dura-Ace is closer to the upper body of the derailleur and the entire inner and outer plate assembly is slightly higher when fully retracted on Dura-Ace than it is on Ultegra.
Since the cable barrel adjuster on Dura-Ace is closer to the body the cable mounting point is closer too, riding up higher and tighter to the outer link of the derailleur.
As viewed from the front the diameter of the lower body of the Dura-Ace is slightly smaller at 20 millimeters than the Ultegra at 22 millimeters, likely another of the small differences that account for the 10-12.8% weight difference between the Ultegra derailleur and Dura-Ace.
Conclusion: Dura-Ace vs. Ultegra Rear Derailleurs.
The Shimano Dura-Ace RD-7900-SS is 10.0-12.8% lighter weight than Ultegra RD-6700-G. The warranty difference is one year longer for Dura-Ace. The cost difference is 55% lower for Ultegra. There is no difference in shift speed or quality when used with Shimano bar-end shifters since Shimano only makes one bar end shifter. Given the differences in weight, warranty duration, manufacturing and materials, cost and overall performance it is difficult or impossible to detect a difference in performance between the rear derailleurs. There is a difference in durability and weight.
As with the differences in rear derailleurs, the differences between the Shimano Dura-Ace front derailleur and Ultegra front derailleurs are a one year longer warranty for Dura-Ace, lighter weight, higher cost. There is the added distinction of Shimano’s 10% better shifting under load. While there is a 10% reported difference in shift quality under load the majority of front derailleur shift performance is contingent on additional factors such as the chain, chainrings, crank, bottom bracket, cable and housings and frame cable routing.
The bottom line is that if you are deciding between a bike equipped with Shimano Dura-Ace and Ultegra front and rear derailleurs that both work adequately for even the best athletes to win world class events on. The Dura-Ace derailleurs are slightly lighter and more durable, but provide similar shift performance. You likely won’t be able to tell the difference in shift quality alone. The Dura-Ace derailleurs will likely out last the Ultegra but you are paying a premium for one additional year of warranty coverage. If you don’t mind spending significantly more money on the front and rear derailleur you will get improved durability and lighter weight. It is worth noting that few customers ever use a derailleur enough to actually wear it out.