The thread about Campy electronic in '05 motivated me to take a couple pics and post a thread about Mavic Mektronic shifting.
Mavic's wireless Mektronic shifting system uses a traditional cable front derailleur, and a wireless rear derailleur. Shifts within the cassette are then executed with slight pressure on one of several buttons located around the handlebars, which transmits via a unique frequency to the rear derailleur. Batteries are located in the rear derailleur and integrated computer. It appears to me that the rear derailleur has all the usual adjustment features.
There are three locations you can shift from with Mektronic. When your hands are on the tops, there are two buttons located on the computer that allow you to shift into a lower or higher tooth gear.
With your hands on the hoods, you can shift from two locations. There is a button on the top left of the right hood that moves up and down with a little pressure to change gears. you can see this in the photo above.
The other location can also be reached from the drops. There are two buttons here that control the rear derailleur.
The computer is also integrated with the system. It displays the gear that you are in, along with all the usual computer functions minus cadence.
The levers are extremely comfortable and ergonomic, as you can shift from pretty much any position. I have logged roughly 200 miles with Mektronic, and shifting occurs with ease. You can hold the button in to shift multiple gears, or push it rapidly. There is usually a slight delay before the derailleur engages. I would compare this to the time it would take you to shift with Shimano STI levers.
Weakness I see in the system are as follows. The shifters have accidently changed gears over rough bumps on several occasions, but not often enough to become a nuisance. Battery life worries me, as I don't know what would happen if you ran out on a ride - carry a spare?! Also, possible lack of familiarity at LBS's, and future support by Mavic also worry me.
Overall I think this system works magnificently, and is ahead of it's time. However, I don't see the point to spend the R&D to develop such a thing. Is cable shifting so bad? I don't think so. That said, I will probably swap the system out for Dura-ace componentry.
I had the Mavic Zapp gruppo, which predated the Mektronics...it was not wireless.
Shifting was so smooth and precise, and instantaneous, it was a joy. As far as batteries, all the batteries were required to do was to trip a selenoid valve. The front deurailler was manual.
One drawback was that connection from the wire to the deurailler would unplug easily when pulling the bike in or out of the car. One duathlon I didn't notice it until I got on the bike and had to stop and dismount to find out why I wasn't shifting and lost probably 45 seconds, and it knocked me out of the top ten overall.
Another duathlon it simply failed on me during a race and I was stuck in the middle of the rear cog so I had to finish the race with two gears. So it probably deserved to die a failed project, but man was it awesome 99.99% of the time.
Oh, it was fragile. I had a collision with a car and it was broken in pieces...the external cover was plastic and it could not withstand a crash on pavement. Mind you, My TT bike was pretzled and I was hauled away in an ambulance...it was a bad wreck, but I had the impression a traditional duerailler would have been salvageable.