The future of bicycle shifting technology as we know it has finally arrived.
After five years of development, secret field testing under some pro riders, spy shots of the next big thing, and finally its formal introduction to the public at last fall's Interbike Show in Las Vegas, the most talked-about product of 2009 is now in stock (or at least order-able) at your bike shop: Shimano's Electronic Dura Ace.
Rather than using cables to connect your shifters to their respective derailleurs, Shimano Electronic Dura Ace, or Di2, operates using electrical wires and an electrical rather than mechanical signal to shift.
This may seem simple, so simple that you might wonder why no one has thought of it before? People have, the most famous failure being the Mavic Zap group in the 1990s.
There have been many hurdles in making electronic shifting for your road bike. Durability, ease of setup, and battery power have all been issues that Shimano has faced in the last five years of development.
Bikes are exposed to the elements, including rain, cold and warm weather, and maybe snow or mud. Mechanical cables have proved their worth time and again in all the roughest conditions perfectly.
But electric wires? Chances are if you pour water on your electrical socket, bad things will happen. The ability to hold up to weather just as flawlessly as mechanical wires was a hurdle.
Ease of setup and battery sources were another consideration. Road cyclists are notorious for being extremely conscious of their bike's weight. The most innovative system in the world is useless if it is huge and ungainly on the bike.
Despite housing impressive technology, the electronic drivetrain still needs to look and weigh the same as a mechanical drivetrain for it to be a real competitive advantage.
New technologies have allowed Shimano to use an extremely small battery source, one in each shifter and in the front and rear derailleurs to make the system compact and light, just like a mechanical setup.
Since Shimano is introducing the electronic road group, it is safe to say that these challenges have been met. So how well does it work?
The shifters have been completely overhauled from the mechanical Dura Ace to meet the specifications for electronic. The shifters look very similar to Dura Ace but work very differently.
Many people familiar with Shimano will know that you press in the inner black lever for up-shifting (out to your taller gears) and push the entire brake lever sideways for downshifting (in to your climbing gears).
The electronic levers, however, work by pushing the inner "button" in for one up-shift at a time, and pushing in the outer button for downshifts. The brake lever is fixed and does not move sideways.
Each button takes the same amount of effort to push as a computer mouse button, a complete ergonomic departure from anything Shimano, Campagnolo, or SRAM mechanical systems offer.
Those button pushes initiate rapid shifting. Shifting is reportedly 30 percent quicker than mechanical systems, resulting in rear shifting that is instantaneous, quiet, and reliable. The rear derailleur can knock off as many shifts in succession as quickly as you can move your fingertip to shift, without hesitation.
As good as the rear derailleur is, sources have noted that it is the front derailleur that is truly exceptional. Normally to shift the front derailleur and not drop the chain or suffer a rough shift, you need to ease off on your pedal force and swing the lever a rather exaggerated amount.
Not so with electronic. The same mouse button tap you get with the rear shifting is all you need for the front as well.
Ben Edwards from Testrider.com said "the front derailleur will blow your mind," and "the rear shifting is lightning quick and razor sharp, but the front shifting was essentially unbelievable, shifting smoothly from big ring to little ring regardless of your power output completely defied logic."
All this may sound too good to be true: a truly instantaneous drivetrain that responds to your every thought the instant you think about it? It must have a cost. And that it does.
Upon introduction, Shimano marked the price for a complete electronic Dura Ace groupset at a staggering $4,000. That gets you the electronic items; the left and right shifters, the front and rear derailleurs, and the battery pack; and the non-electronic systems carried over from the mechanical system; the crankset, brakes, rear cassette, and chain.
Compare that price to other mechanical groupsets. Shimano's Dura Ace 7900 costs $2,600. Campagnolo Super Record 11 costs $2,600 after some markdowns in the last few months. SRAM Red costs the least of the top-of-the-line drivetrains at $1,600 after some of the same markdowns as Campagnolo.
That $4,000 suddenly puts such a drivetrain out of reach for many. However, according to Competitive Cyclist, the groupset doesn't even cost $4,000. It costs more.
Each derailleur comes with an extra "wiring kit" that is essential to its functioning and adds a sneaky several hundred dollars, and a device called the "System Checker/Programmer" which is also essential.
The real cost of the Electronic Dura Ace groupset? An even more staggering $5,200.
Only the very well heeled need apply to be the first to have the next evolution of bike shifting technology. A few manufacturers are already offering Di2-equipped bikes in their lineup, such as Specialized, which will start to sell a top-level Tarmac SL2 equipped with Di2 for $9,900.
As with all new technology, prices will come down, manufacturing processes will get cheaper, and within a few years, the price of electronic may rival the price of the current cream of top-level mechanical groupsets.
But for now, the wave of shifting future has arrived.