Been awhile for a bit and returned to see Di2 stuff being bandied about. Maybe I'm just thick but I don't get it. Why? Weight? Reliability? Cost?

Weight: I can't see it being lighter with batteries, actuators, and power cables.

Reliability - sure - till your batteries are dead. And I wonder how the components do in a crash...

Cost - lmao.

Maybe its smoother shifting! I have 9 spd Ultegra that shifts just fine after many years. I'm not really wringing my hands for something "smoother".

Could the n+1 speed game is over due to physical limitations...

Now - an efficient CVT - that would be impressive. It could also be a death knell for groupo manufacturers.

As a famous poet once said,

Why ask why?

Wow, what a unique topic.

Another gadget to make cycling more complicated, along with computers, heart rate monitors, cadence sensors, power meters, GPS, etc., but more importantly, more profitable.

It's not that complicated--if you don't get it, don't buy it.

This.

Bike weenies are going to spend money on something, whether they need it or not.

Yawn!

Good point.

As a famous philosopher once said,

All is nous.

That is all.

I see the kids are out of school today.

Sorry I'm not amusing you junior. I'll try to do better.

Weights not much of an issue because its very easy to build a bike under the UCI limit. Rather than adding ballast the weight can go into technology......

It does in fact shift a lot better than ultegra 9 speed.

How? My SRAM Red shifts, every time. How would something else that shifts every time shift better?

It shifts faster, more accurately, will never misshift, and never needs adjustment. One of the main advantages is that the front derailer can shift under load. Even if you are sprinting in the small ring up a steep hill and want to go to the big ring, it will shift immediately.

Di2 is self-adjusting, so no missed shifts, no phantom shifting, no dropped chains. Shifting works flawlessly in good or bad conditions. You can double-shift effortlessly and without any fear of error. You can put the shift controls anywhere on the bike, which is critical for TT's.

It's only 50g heavier. You don't need robust mechanical parts inside the levers, and wires are lighter than mechanical cables.

The batteries last for a very long time, and iirc the FD will go out before the RD. You'd have to be pretty oblivious to run out of battery power.

Di2 is pretty much self-adjusting, so you wind up performing minimal derailleur maintenance.

I doubt any specific component, high-end or low-end, will genuinely do all that much better than another in a crash.

In terms of cost, Shimano trickles down their tech, as indicated by the electronic Ultegra due out some time this year. In 5 years or so, cost will be much less of an issue. In 10 years, it'll be the same cost as 105 today, if not less.


There is clearly a bit of "ooh shiny" going on, and since it's so expensive and rare it can be viewed as a status symbol. But that's no different than mechanical DA, SRAM Red, Campy Super Record, S-Works and Cervelo R5ca framesets, etc etc

At this point, especially given the cost, it's only really useful for pros. As the price drops, eventually it will make sense for dedicated amateurs, especially TT'ers and triathletes.

If you don't need it, you don't need it, and there is no reason for you to be unhappy or to change.

Needing to shift to your big ring because you are sprinting up a steep hill ... sounds bizarre.

On my hybrid with SRAM Attack gripshifts, I can shift both my derailleurs for multiple gears at once in all directions ... even under moderate load.
I can even jump 8 gears in one pull when going down (it's a reversed XT derailleur) ... I doubt Di2 can do it as fast as that.
I haven't adjusted them for over a year and they have never misshifted yet.

I don't see how anything can beat that.

The only benefit I see is, like bacciagalupe said, on TT bikes to be able to put shifters next to the brakes aswell.

Contador attacked on Etna yesterday in the Giro d'Italia in this manner.

Most recreational cyclists and even many pro cyclists would not be attacking a climb in such a manner, however.

I guess di2 isn't for you. Your 8 speed gripshifts are clearly the pinnacle of bicycle shifter technology.

Contador IS bizarre

If they were 8 speed gripshifts, I wouldn't be able to shift 8 gears in one pull ... clearly they must be 9 speed
I'm not saying they are anything ... I'm just saying what they can do.
Try it: use those shifters with XT cables on a "rapid rise" XT derailleur ... it works flawlessly.

Anyone had their Di2 get really soaking wet yet?

Damn, you figured out the one thing that Shimano forgot to test!

Haha ... no seriously though ... I wouldn't want to ride a mountainbike through a watery-muddy course with electronic shifting on it.
Regular shifting is more than reliable enough, imo.

Good post. It's the new "thing" and as such is very expensive. Just like big-screen TVs. 10 years ago a 50" inch projection TV cost $5000, now you can get a 50" plasma for $500. I have a feeling that this electronic shifting thing is going to be what most bikes come with standard 5-10 years from now.

Why would you put a road group on a mtn bike?

Definately.
The option of having the cable completely in the frame is great, once standardized.
With electric cables you can even let them pass through the stem and the headtube and completely through the handlebars.
No cable will be visible on the outside and the drag from the cables will be history.
As with all these new things though, it's better to wait until the third generation or so as you'll have better stuff for less

Why not?
It has already been done ... just for fun they have put Di2 on mountainbikes.