Shimano Dura-Ace 7970 Di2
For years, the increased accuracy, smoothness and reliability of electronic shifting has been perhaps the ultimate goal for high-performance-bike designers. After several companies' attempts failed—suffering from breakdowns in bad weather, poor battery life or unbearable complexity—Shimano's Dura-Ace Di2 has finally delivered it.
The Di2's black carbon-fiber setup looks traditional, but what appears to be a standard shifter is actually a switch that sends gear changes via a wire to sensors in the front and rear derailleurs (the parts that guide the chain up and down the gears). A CPU in the front derailleur, in turn, signals motors that move the chain across the bike's front and rear cogs. Steel cables, a source of frustration in shifting, have been eliminated. They probably won't be coming back.
The electronic system makes gear changes faster and virtually eliminates missed shifts, which can interrupt pedaling rhythm or even cause the chain to fall off. And the Di2 is two ounces lighter than last year's mechanical Dura-Ace group.
Shimano spent three years testing the system, and it was used extensively in this year's Tour de France. Available now on high-end 2009 bikes, electronic shifting should work its way into most bike makers' entire product lines over the next five years. $2,100; bike.shimano.com
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Gotta tell you guys...the price listed isn't even close. Also.....no matter how much you spend on electronic shifting....it won't make you any faster.
Yeah, but coming from a biker, it sounds good. It wasn't meant for making you go faster, and it never said that. It just makes shifting easier. My bike comely has problems shifting gears.
I'm not a luddite by any means and certainly don't want to be confrontational but I've been racing 25 years and have had exactly 2 broken derailleur cables. After the first one I've carried a spare ever since while training. If I went electronic for the next 25 years I wonder how many times I'd be stranded on the side of the road? How many times I'd be without a ride for a few days or even weeks as I get my newest electronic gizmo repaired if it broke down? The more complicated we make things, the more apt they are to having problems and the more specialized the service required tends to be. I'm sure it shifts like a dream but so do mine. In the future it may win me over. After years of tried and true service though. Much like when I waited years to switch from the bombproof downtube shifters to indexed STI levers. I suggest that anyone planning on purchasing this product carefully weigh the pros and cons....and carry another newfangled gadget, the cell phone, on every ride taken with this new groupo. Unless, of course, you have your team car follwing behind you.
Ditch the cables and go with a hydraulic gear shifter mechanism. There are patents filed for this but why hasn't any of the companies put out products utilizing hyrdaulics? It could be much more accurate, durable, and faster than traditional cable style gear shifters. Thats just my two cents
Wait...if the battery pack runs down you can't shift?? I'd rather see cables remain in the mass market and let the elite riders fiddle with batteries. I've only had one problem with shifters in 4000 miles and it was from a shifter handle itself wearing out. The cables have never been a problem for me. Especially for mountain bikes but also for all, what if a wire gets cut in a crash or water gets into the electronics? This seems like a needless complication to a simple machine.
So, roughly 1 and a half years after they hit the market, the price is still around $2500 for the electronic shifting components. I don't think there has been a trickle down to the Ultegra line of components.
Reportedly, the di2 components don't work as well unless you are also using dura ace components, so the total price rockets up to like $5,000 if you have to upgrade to the dura ace 7900 set.