Shimano Dura Ace Di2 – Electronic Road Bike Shifting Review

Josh at Outspokin’ Bicycles in Woodstock, GA hit me up earlier this week with an invitation. This invite was for a Shimano Dura Ace Di2 launch party at their shop where I would get to try out the new ultra high end, electronic road bike shifting groupo from Shimano. The Shimano Dura Ace Di2 road bike groupo has been getting a lot of press lately for both its price and features.

With quotes like these:

“GRAND AWARD WINNER FOR BEST RECREATION PRODUCT OF 2008”
– Popular Science Magazine

“…changing gears has never been easier.”
– Bicycling Magazine

“You can stay on the gas and flip through the gears with no hesitation. It’s seamless power.”
-Chris d’Aluisio, director of advanced research and development, Specialized

“immediate and very smooth and accurate…. It’s super nice.”
-Frankie Andreu, former Tour de France racer and TV cycling commentator

I was primed and ready to try out Shimano Di2…the component group to end all component groups.

More On the Shimano Dura Ace Di2 Groupo

Shimano Press Release:

Shimano Dura Ace Di2Shimano officially announced Dura-Ace Di2, a technologically advanced, electronic shifting option for the all new 7900 series Dura-Ace. Comprised of Dual Control type shift / brake levers, front derailleur, rear derailleur, and a battery pack, the new Dura-Ace Di2 7970 components provide precision electronic performance and integrate seamlessly with components from the 7900 series Dura-Ace group while adding only 68 grams to the entire group.

Electrically actuated shifting significantly eliminates issues associated with cable friction and contamination because the derailleurs respond to electrical impulses that are delivered in fractions of a second. The shifters are now merely switches which also allows for creative placement of optional remote shifters while also reducing the weight and profile of the main shift units. Derailleur movement is precisely controlled through computer automated movement and servo motors creating perfectly synchronized and calibrated shifts every time.

ST-7970 Dura-Ace Di2 Dual Control Levers
By using unidirectional carbon fiber brake lever blades and eliminating all of the mechanical shifter parts, the new Dual Control lever weight is reduced by over 155g over the mechanical version. The ergonomics are slimmed down and further refined for a comfortable grip.

The wiring harness for the shifters is designed to accept the all new FlightDeck computer (SC-7900) featuring heart rate, altitude, grade, cadence, estimated caloric consumption, gear position, and battery life all directly downloadable data via a wireless connection.

RD-7970 Dura-Ace Di2 Rear Derailleur
Like the 7900 mechanical derailleur, the 7970 has a new carbon fiber rear pulley cage and the new design is compatible with wider range cogsets, accommodating up to a 27 tooth cog. The differences are the fact that the unit is now driven by a servo motor instead of a cable and spring, so shifts are identical and precise every time as the computer control unit analyzes each shift.

The derailleur has a built in mechanism that will allow the body to move inward under impact to reduce the potential for damage in the case of a crash. Cycling through the shifting a couple of times allows the shifter and rear derailleur to automatically re-synchronize.

FD-7970 Dura-Ace Di2 Front Derailleur
The front derailleur is the “brains” of the system. The integrated ultra-compact CPU not only ensures that shifting is perfect for both the front and rear derailleurs individually, but also by monitoring the position of each, creates a front derailleur that tracks the chain and requires zero manual trim without sacrificing any shifting speed. The front derailleur logic also performs the inward shift from the big chainring in two parts to eliminate chain drop, with both actions measured in fractions of a second.

SM-BTR1 Dura-Ace Di2 Battery Pack
The 7.4V, high performance Lithium Ion battery is designed to deliver reliable, long life even in the worst conditions. In conditions requiring consistent and frequent shifting, the battery is capable of 1000 kilometers of use.

The battery is rechargeable and comes with a mount that easily adapts to most bikes. Lithium Ion technology is lighter, more compact and better performing than other power sources, making it a clear choice for Di2.

Dura-Ace Di2 redefines the highest level of component performance and solidifies the brand as the benchmark for professional cyclists and road cycling enthusiasts alike. Dura Ace Di2 will be available January 2009.

Enough Tech Talk – How Does Shimano Di2 Shift?

First, at $4,700 US (yes you are reading the sign correctly in the picture below…try not to throw up all over your keyboard), this group better make me a faster rider. You know something is really expensive when hard core roadies are going…”I don’t know…that is a lot of money for a component group.”

Trying to forget about the price, in all honesty…the shifting on the Shimano Dura Ace Di2 setup is CRISP! The new shifters took some getting used to. I actually couldn’t figure it out at first and it took a little instruction to realize the push/push function of the electronic shifters. There are two seperate paddles as you can see in the pictures below. With each very short throw, the derailleur moves through the motions almost effortlessly.

On the rear shifting setup, there is one feature that is going to be greatly missed…there is no option to move up multiple gears on the cassette. You can only move up one at a time as you get ready for that stupid steep climb up ahead. Even though you can shift up pretty rapidly because of the fast action and short throw, you still can’t just dump the cassette when needed.

The front derailleur shifting on the Dura Ace Di2 system was flawless. Shifting to the big ring has never been easier and it is done with a short click of the shifter. You no longer have to throw the brake lever inboard like conventional Shimano cable driven systems. The front derailleur also auto trims based on your rear gear selection. As you shift through the rear cassette, it automatically adjusts to prevent the chain from rubbing on the FD cage. The front derailleur just shifts quietly and perfectly every time and this is the biggest selling point of the Dura Ace Di2 in my opinion.

The other obvious selling point of the Dura Ace Di2 from Shimano is the absence of cable friction and stretch.

Is the Shimano Dura Ace Di2 Group worth it?

For me…no. That is a lot of money to throw down on electric shifting. It was cool to play around with for awhile, but in the end…I have zero issues out of my current Dura Ace group and I do not see the need to spend that kind of money. Is it cool to see technology progressing and to have other options? Sure! But for this rider…I’ll still to cable driven for now.

Big thanks to Josh and the crew at Outspokin’ Bicycles for the invite. I took a ton of pictures as you can see below. Like a true mountain biker…I couldn’t help taking pictures of some of the fat tire porn around the shop, so enjoy the shots.

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