I'm Brad. I work upstairs @ the Loft.
This is the first in what I'm hoping is a series of cycling related (and possibly food related!) posts. If I think it's cool, interesting, and/or just plain strange then I'll share it with you here.
Introduction? Check.
Statement of purpose? Check.
The Main Event!
Shimano's new Di2 group may just be the single coolest thing I've ever put my mitts on. It's the real deal and it's here to stay. I knew it was coming. I've been seeing spying shots for years. I tried to temper my unbridled enthusiasm for shiny new parts with the correct amount of skepticism. Mavic tried the electronic thing with Zap and Mektronic years ago and it was an abomination. It was so bad that I've tried to erase it from my memory.
Could Shimano succeed where Mavic failed? Sure...Shimano has years of engineering expertise and the deep pockets to finance such an ambitious endeavor but making the leap from producing cable actuated derailleurs and shifters to a fully electronic drivetrain is a huge one. Could they actually bring a viable product to market?
"WAY BACK! WAAAAAAAAAAY BACK! DEEP INTO THE NIGHT! GRAND SLAM!!!!!!!"
I've ridden it. It's everything I had hoped it would be. It's lightning quick. It's quiet. It's so good that I dream about it at night. It's also bloody expensive! Figure on spending close to $5,000 for a complete group.
How'd they do it?
Visually, the 7970 Di2 parts aren't too different from their 7900 mechanical cousins. The crankset, chain, cassette and brakes are standard issue from the mechanical group. The front and rear derailleurs sport fancy new additions in the form of a solenoid driven motor (for the rear)
and a solenoid driven motor plus CPU (for the front). The CPU is what enables the derailleur to execute it's most amazing function:Automatically trimming itself to eliminate chain rub. Run Big/Big until the cows come home. The CPU keeps track of how many rear shifts you've made and executes small movements of the front derailleur to compensate. I've had my hands all over this stuff for weeks and this is the part of the system that still amazes me. The CPU also plays a role in making the rear shifts flawless. For every shift, the "brain" overshoots each cog by a small amount and then auto-corrects it's position to perfectly align the cage and chain with each cog. Add those two things together and you've got 100% flawless shifting. Every time. The front derailleur will work with Standard and Compact cranks. The rear derailleur has a maximum capacity of 27 teeth.
What about the shifters?
The glowing praise I've heaped upon the front and rear derailleurs would mean nothing if the shifters were uncomfortable. They're not. They've got a slightly narrower body (thanks to the elimination of all of the shifting mechanisms) than the 7900 mechanical levers and a less bulbous front end. I think they're the most comfortable levers Shimano has ever released. The brake lever itself is reach adjustable. The shifting buttons are easy to reach and have a solid engagement akin to a mouse click. The shift wires themselves have a small module attached that can be zip-tied to one of the brake cables. This module acts as both a battery life indicator and as a pseudo barrel adjuster. Holding down one of the shift buttons will give you a visual representation( via LED) of your current battery charge.
Solid Green = 100% charge
Flashing Green = 50% charge
Solid Red = 25% charge
Flashing Red = Critically low charge
Pressing the button on the module for two seconds will enter the derailleur adjustment mode. Once in this mode, the shifter buttons will allow you to fine tune the position of the rear derailleur in 0.2 mm increments. This is only required during the initial set up. Unlike traditional metal cables, the wiring is impervious to the elements. No cable breakdown or housing failure means little to no adjustment after it's installed.
How long does the battery last?
Instead of using an exotic and untested battery, Shimano chose to use a fairly standard rechargeable Lithium-Ion battery for the Di2 system. Shimano claims 1200-1500 miles of life on a full battery. Reports from actual users have supported this claim. That's a ton of miles from a battery that weighs about as much as some modern smart phones. It will fully recharge in 90 minutes from 0%. The battery mount attaches to the downtube via the water bottle bosses.
How does it ride?
Dura-Ace has always been the standard by which other road groups have been judged. The Di2 group is on a completely different level. It's worth every penny and I can't wait to get it on my bike. Push the buttons and it shifts. No questions. No hiccups. Shift the into the big ring under full power and it doesn't hesitate. Shift the rear derailleur in the middle of a full blown sprint and it happily executes it's task.
Now I just have to figure out a way to finance a group for myself!
Come on into the shop and check it out. We've got it installed on a beautiful Parlee Z4.
If you've got any questions you can email me via the address below or call the shop directly.
Email: mechanic@cycleloft.com
Phone: 781-272-0870 x5
Cheers!
B-Rad
