BrainInAJar

was just thinking about Di2 this morning, and the features that would make me start throwing money at it immediately.

Progressive shifting or whatever we're calling it (computer choosing the right ring/cog combo based on gear ratios, rather than rider input)

Somehow removable brake cables. I'd love to be able to pull off my bars and replace them with TT/tri bars by just unhooking a couple cables and pulling off the stem. Putting an end to clip-on aero bars

any other nifty ideas that'd make Di2 perfect?

merlinextraligh

You can already do this with cable splitters. Common on bikes with S&S couplers.

dorkypants

Yeah, but cable splitters aren't "aerodynamic", maybe add a few grams (a weight-weenie no-no), and then there's the potential dork/Fred factor (what? a travel-bike widget on a TT bike?).

RT

I wish it would go away. Seriously. That it is even a notion - a computer choosing your gear for you is silly. It would take the sport out of racing, and the fun out of recreational cycling.

Meet George Jetson.

BrainInAJar

not choosing your gear for you, just picking the next gear-inch progression

AdelaaR

Picking the next gear this way by computer would mean that most if not all of your gear changes would be both the front and the rear changing, which will make it impossible to keep power while changing and will make the changes longer to perform.

Bad idea.

AdelaaR

The only reason I could ever see why someone would have Di2 is for a TT bike to be able to shift on both the aerobar and the basebar, but even there it's not really necessary unless one has misjudged which gear to be in after a tight turn or similar.
For all other uses ... the current gears are just fine ... I know mine are

gregf83 

There's nothing saying the computer has to be stupid about how it picks the gears. You could even have it programmed according to your preferences.

That said, is anyone really that busy on the bike that they can't shift front and rear shifters simultaneously once in a while. I suppose that's why most cars on America are automatic rather than standard shift.

AdelaaR

... and that's exactly why I'm in Belgium and my car has a manual shift
Manual shifting gives you more freedom and thus more and better options, once you get used to it.
They use it in races for a reason.

I am, when riding my bike, actually always very busy trying to avoid debris, potholes, cars and regulating my breathing and cadence ... I don't have time left to shift gear inches at a time by changing both front and rear at the same time ... also it'll get me out of my cadence and ruin my speed.

I've got a 11-23 10-speed cassette too ... the spacing is close enough for my liking.

gregf83 

You need better gears. On Campy it takes no time to shift simultaneously front and rear. I can't imagine it's that much more difficult on Shimano or SRAM.

AdelaaR

I've got 6700 and it does work fine, but it's always better to simply change in the rear, especially when at high power.

merlinextraligh

One of the advantages of Di2 is that the front shifts are so good that it's easy to shift the front seemlessly under power.

Fairwheel bikes has already made a MTB with sequential Di2 shifting.

Single shifter sequential shifting is very likely to be an option on the next Di2 group.

zonatandem

So when is the last time you actually won a TT?

AdelaaR

Interesting.
I still wouldn't want to shift both at the same time all of the time though.
I've got a Dura Ace TT-shifter with a 6700 FD ... works very well for front shifting under load ... hasn't failed me yet.

AdelaaR

Never.
I don't really plan to either ... I do TT's for fun
What does it matter?

Nerull

A lot of people said the exact same thing about STI.

gregf83 

So you don't ever ride on 'small ring' hills?

patentcad

Yeah, I put it on my road bike, it was great, next week I pick up my TT bike with Di2, that will be perfect.

Mithrandir

Except one of the benefits of Di2 is that it lets you shift under full power. Good idea.

Mithrandir

I don't see it working that way to be honest. Here's an example of how I see it working.

I run 3x7 at the moment. The 3 ring is 28% higher than the 2 ring, and my cassette is closely spaced, so that 2-7 is roughly equivalent to 3-3, and 2-6 is close to 3-2. I cruise from 2-5 to 2-7 most often. The next gear up from 2-7 is 3-4, and I can handle 3-4 for moderate distances. Problem is on flats, I'm not quite able to handle 3-5 steadily yet. So when shifting up I tend to go from 2-6 to 2-7, then I should go to 3-4 and then up again to 3-5. But since I rarely get to 3-5 before I encounter an incline, I find myself shifting from 2-7 to 3-4, back down to 2-7, all in a relatively short time frame. There are no words to explain exactly how annoying this is, so what tends to happen is I get to 2-7 and stay there, even if I could go up again. I don't, because I know I'll just have to do 4 shifts shortly.

So here's what I see Di2 doing for me.
When gearing up it would seamlessly go 2-5, 2-6, 3-3, 3-4, 3-5, etc.
When gearing down it would go 3-5, 3-4, 3-3, 2-6, 2-5, etc.


Basically instead of shifting between all the individual gears exactly in order, it will try to stay on the same chainring until cross chaining becomes an issue, and then switch to the next biggest or smallest chainring on demand. In my example I'm assuming it's programmed to avoid 1-6, 1-7, 2-1, 2-7, 3-1, and 3-2. This way the only time it will shift in front will be if you switch from 2-6 to 3-3, and vice versa, and whatever gears form the boundary between chainring 1 and 2. No different from how you would switch the gears manually by hand, really; just avoids the fancy fingerwork of switching both derailleurs at once, and 3 to 4 gears on the cassette at the same time.

ilovecycling

You guys are making this too complicated. It doesn't even need to automatically shift the front and rear simultaneously. It would make more sense if #1 you could switch between manual and auto on the fly, and #2 it only shifted the rear automatically. You could set a preferred cadence range so it can shift up or down the cassette to keep you at that preferred cadence. If you start to mash on it and get the cadence up past a certain point, it will drop down to the next smaller cog. It doesn't need to be that complex to where it does math based on the gear ratio in inches.

The front rings would always be manually controlled. If you are climbing a more serious hill or mountain, you will be totally aware of it and you could easily shift down to the smaller ring up front. Then the rear would still shift automatically based on cadence only.

Nerull

You guys are talking about two completely different things. Autoshifting sounds like one of those features which sounds good until you actually try to use it. But in any case, what other people are talking about is sequential shifting.

Hothead286

Three words.

Ice cream machine.

AdelaaR

Hahaha

guadzilla

ftw!