Welcome to part 2 of my 2013 Shimano introduction. Unlike part 1 for the mechanical Dura-Ace 9000 group, I did not get the chance to ride 9070 Di2 for this review. However I don’t feel bad since there aren’t even any prototypes in the U.S. that I know of, so I’d be surprised if more than just a couple of people have actually ridden it. I’m not going to bother talking about the cranks, brakes, cassette, or chain since that is all the same as 9000 and was covered in part 1. So we’re going to focus on just the electronic parts of Di2.
Availability is still unknown but we’re thinking we’ll see the first real world groups at Eurobike/Interbike in September 2012 with availability starting near the end of the year. For pricing, Shimano claims the price goes up 13% (though my math says it’s only 6%) to an MSRP of $4140 from the previous $3900, which I believe is still a lot less expensive than the original Dura Ace 7970 price when it was introduced.
In terms of compatibility with Ultegra, there does seem to be a good amount of it. The electronics package will be roughly the same for both kits, so wires, batteries etc will move nicely from one group to the other. The SM-PCE1 which is the interface for your computer, will also work on both Ultegra and Dura Ace. It allows you to program what each button does, the speed and number of multi-shifts, and perform diagnostics.
Shimano 9070 Dura Ace Di2 and Weight
Shimano’s engineers made it a priority to shave weight off this new Di2, and they did an impressive job of it — the group is down a whopping 172 grams. That means that with full groups including cables and housings, and all the electronic parts 9070 Di2 should be about 20 grams lighter than 9000. Every manufacturer seems to have only one thing in common with how they weigh their groups, that thing being that they all weigh them differently. So over the years I’ve made it a point to weigh all of them myself using full groups with cables and housings of the same length, chains with the same amount of links and all needed pieces included. I’ve posted my most recent results here on Weight Weenies. So knowing the weight savings of the new groups we can get a pretty good estimate of the actual complete group weight by working backwards. I weighed a complete 7900 group at 2277 grams. The core components for 9000 save 77 grams, which takes the complete equalized group weight down to 2200 grams. I weighed a 7970 group complete with everything at 2350.6 grams. The core components for 9070 shave 172 grams which would take the complete group down to 2178.6 grams — roughly 20 grams lighter than mechanical. That’s a huge step since one of the big sticking points for Di2 was that it was so much heavier than mechanical. Even if those numbers aren’t exact, it’s pretty safe to say there won’t be a substantial difference between the two either way. In fact there really isn’t even much of a difference in weight between 9070 Di2 vs. Campag Super Record mechanical and 2012 Sram Red mechanical. In that above link you’ll see I reported on the complete groupset weight listings for those groups as well. So if I had to predict how this would all pan out in terms of weight, it seems Shimano has pared Di2 9070 down to within roughly 50 grams of the lightest group on the market. Now let’s look at some of the pieces in a little more detail and see where the weight came off and what other changes we can see.
The shifters drop 18 grams. The basic hood shape is unchanged. The hood does become a dual density hood with two different compounds of rubber. The shift buttons are larger albeit with the same shape and location. The two ports become 3. One to hook the shifter into the system, one for an accessory like a TT or climbing shifter, and a 3-port which works only with the refined sprint shifter.
The sprint shifter has its own port. This is because it’s the only shifter from Shimano this year that does not have its own onboard processor. This means for those of you hacking types, remote buttons could be created and integrated using this specific port. Though with all the changes this year I don’t see much need to hack anything.
The TT brake lever and shifter combo continues unchanged. The sprint shifter gets just a small shape refinement as does the climbing shifter. The bar end shifter is still around but gets a newer, more specialized purpose as more of a tri shifter. And then there will be a whole other new TT-specific set of bar end shifters, by request of pro tour riders. These new shifters are smaller and more aero with buttons on the top instead of on the inside. The new TT shifters shift only the rear derailleur — one button on each aero bar, one for upshift and one for downshift. The front shifter will have to shifted from another location, which seems perfectly logical for a TT setup.
The biggest change I see in the rear shifter is for a programmable multi-shift function. This allows dumping your selected number of gears. Push the button quickly once and you get a single shift, pushing and holding the button results in shifting however many shifts you have programmed it to execute. You can choose anything from a double shift up to 10 shifts moving from one end of the cassette to the other.
Both front and rear derailleurs shrink in size and weight, with the rear dropping 8 grams and the front dropping 10 grams. The front also gets a new wire entry point on the back side of the derailleur instead of on the front. This will clean up the wiring path even more and allow more flexibility in wire paths.
There are more stock battery options this year. You can of course use the standard Di2 battery or opt for their cylindrical internal seatpost battery. The seatpost battery will have clips to hold it into place inside different diameter seatposts. Shimano will also release their own PRO post with a battery already integrated inside it. For charging the internal battery you don’t have to remove it, charging will be done through the Junction-A box at the front of the bike. The weight of the internal battery is expected to be right at 35 grams, and includes weight savings not just from the battery but from a different mount as well.
Junction Box (The Brain)
Since we’ve mentioned the Junction-A this seems like a good place to mention more about that. There is the standard Junction-A box which has 3 ports but there is also a variation that will include 5 ports. With the 5-port version and the standard shifter levers you could run every combination of shifter available all at the same time — TT/Tri, climbing, sprinting, plus the conventional road levers (known as ST). The 5-port also has an Ant+ transmitter integrating with the new Flight Deck.
Flight Deck looks to be quite well thought out. Functions can be selected using remote buttons in the shifters themselves or using a touch screen. Awaiting more information about the new Flight Deck, it is still somewhat limited but nevertheless one can pick out some things such as power, cadence, gear indicator, heart rate, and battery level. We’re also hearing that it can handle some simple diagnostic tasks for troubleshooting. One interesting thing about the Flight Deck is that it is 10 and 11 speed compatible, which confirms full compatibility with Ultegra parts. With the ability to update firmware through downloads now, it also adds some interesting possibilities. Could current Ultegra eventually be changed to 11 speed through a simple firm ware update? We don’t see any reason why this wouldn’t be the case.
We’ll provide you with more information as we’re able to get it. But for now it seems more likely to me that Di2 will spell an end for mechanical Dura Ace in the coming years.
And for all you weight weenies, here are the individual component weights:
Shifters, 237 grams
Rear derailleur: 217 grams
Front derailleur: 114 grams
Brakes: 297 grams
Cassette: 166 grams
Chain: 243 grams
Crank and bb: 683 grams
Read More: Dura Ace 9000 and Shimano Wheels