The group of cyclists that can take the biggest advantages of this new technology are the triathletes. But, unless its a hilly course, how many times do you actually shift?
For the road group, Shimano has added sprinters switches as well as climbers switches and, the way they are designed, you can add an almost unlimited number of switches.
Let’s say for example you have a Cervelo S5. Getting the bike ready for an upcoming triathlon, you add aero bars to your S5. Running Di2, you can now add shift points to the end of the aero bars as well as shift from the road levers. You can even add a sprinters switch as well as a climbers switch to the bars. A truly versatile system.
BUT, lets talk honestly about TT. Aero trumps everything else and to be honest, MOST time-trialers and triathletes would benefit far more from a bike fit AND using the correct sized components, than gain any advantage of using electric shifting.
Most triathletes are so ill-fitted that their position in their aero bars are usually worse than a “roadie” positioned on the top of their bars.
Get a bike fit first, get the correct sized components (including the right sized frame) and you wont believe how much faster, more comfortable and more efficiently you will be riding! Then worry about Di2 vs Mechanical.
My thoughts, having ridden both Di2 and Mechanical is that the mechanical is pretty darn good. Especially the new DuraAce-9000 group. The Ultegra-6800 benefits from trickle-down technology.
Shimano not only addressed all of the “issues” of the 7900 group, but added many of their wish-list enhancements as well.
The new Mechanical systems shift so crisp that it almost seems as if you are running a Di2.
The new stuff is far superior to the last generation that IMHO, the mechanical is the way to go – especially if you want to save a few dollars…since it does force you to go all-in with 11-speed.
Now, with that being said, there are simple ways to optimize your older mechanical groups (DuraAce-7900) so they shift
and run much more smoothly. Two fairly inexpensive things to change are (1) replace your cables and housing with the new DuraAce 9000 cables and housing. (2) Replace your 10-speed chain with the new DuraAce-9000 11-speed chain.
I brought my DA7900 back to life and it shifts and brakes as smoothly as the old 7800 does.
I have always enjoyed bicycling and, through a series of coincidences, became a Bicycle Industry Consultant and Product Tester. I continue to test prototype products for companies and publish only off the shelf production products on biketestreviews.com.