The evolution of the bicycle shifting continues. Shimano now has its new electronic Dura Ace Di2 gruppo. Sure there have been other companies that have tried to master this but I think Shimano is on to something with this one.

Shimano Dura Ace
First let me start with the weight of the Di2. This gruppo only weighs 68 grams more than the Dura Ace 7900. For what you get with the gruppo, this additional weight is negligible. The additional weight comes from the battery. Do not get fooled into thinking this is a heavy weight gruppo by the addition of a battery. This is very light!

A concern that you may have is the battery life. The Shimano Di2 lithium ion battery life is well over 1000 kilometers in constant shifting conditions. The battery is also something that can be easily replaced. If you are the paranoid type, you can also purchase an extra battery to carry with you but I assure you that with the battery life indicator, you should be able to catch this in time.

Shimano Di2 Front Derailleur
Perhaps one of the coolest features of this gruppo is that the front derailleur has an auto trim feature on it. What this means is when you shift your rear derailleur, your front derailleur will adjust automatically so you will no longer have your chain rubbing.
Something that will help not just the professional rider is that speed of the shifting. The Shimano Di2 electronic shifter shifts 30% faster than non-electronic shifting. This is also a really smooth transition between gears. If you ever get the opportunity to test ride this gruppo make sure you do. It will truly amaze you and you too can see why this was the product of the year at Interbike 2008!

The only down side to this gruppo is its price. To upgrade from Dura Ace 7900 is roughly $2,500.00. I will say that this is really worth it so save your money for this upgrade. This is an awesome gruppo to have on your bike. When you see it in action you will have a greater appreciation for it and understand the why it costs as much as it does.