Best put some pedals on the bike first!

hey Rob, if you'd a pound for every wit like McBain you'd have, let's see now, 50 pence.

That's because I didn't explain that Di2 also has 'Pedalcloak technology'...I may have just made that up!

this kit will look really nice when they start making dedicated frames with internal cabling and recessed battery to suit.

No doubt the Japanese will not have factored in 'British' weather? Come on, British weather is nothing special compared to the extremes of Japanese weather, what with typhoons, extreme heat, torretial rains, sub zero winters... thats of course when the weather is merely normal over there.

Great. They've just defined themselves as the 'toyota' of the component world... functional but butt ugly... hehehe

Come on Crabstix, British weather can stop trains, make getting to work a little bit difficult...Surely nothing is a match for that...

Yuk - don't like that huge collection of zip-tied cables in front of the head tube. Sure to get clogged with flies, road grime, mud etc, not to mention the inevitable cable buzz against the head tube - could be very annoying!

Can't quite understand why they didn't go the whole hog and develop a wire-free system? As most pro-bikes come way under the UCI limit, I can't see the extra weight being an issue?

I think it'll be important to check out how it goes in situations where you need to tweak front and rear shifting e.g. swap cranks from std to compact or new thicker/thinner chain (kmc vs da) or when you put on different wheelset/cassettes.

Yes, the cable ties are a bit unsightly but no doubt more manufacturers will catch up and get onboard with Di2 specific designs as Cannondale have with the SuperSix Di2 bike. There is no discernible buzz against the headtube as the wires aren't as stiff/under tension in the the same way gear outer. They're just rubber coated flexible wires.

The system wasn't developed around a wireless system as a wireless system would require much more power to operate meaning seperate batteries for the shifters and front and rear mechs - pushing it well over any acceptable weight for racing. The wireless was also found to be open to more contamination from other digital signals (from computers, GPS, etc) - a closed wired system is totally free from this.

In regards to the comments about weather affectign the system:

http://www.bikeradar.com/news/article/shimano-dura-ace-di2-electronic-first-ride-18283

check out the 5th image from the end.

They use marine-grade connections for all joints. water, salt, and general road crap does not affect it at all.

A great shame it's not wireless. Imagine the fun that could be had by remotely shifting the gears on someone else's bike.

Ground-breaking Di2 electronic groupset. Other than being a groupset, My Question is whats so ground breaking, I was running electronic shifting on my bike twenty years ago. They were called Mavic Zaps.

I have tried this only on a trainer only but i have to say very smooth and precise shifts will be interested to see how the testers find it but first impression was that it was pretty good

What's wrong with a cable and some mechanical reliability? Frankly, if you have to start charging the batteries so you can ride your bike in more than one gear it's never going to fly. And looking like it does... well, i'll take a rain check, thanks.