On Friday, July 12, 2019 at 10:50:47 PM UTC+2, Tom Kunich wrote:
On Thursday, July 11, 2019 at 5:41:42 AM UTC-7, wrote:
On Wednesday, July 10, 2019 at 10:19:22 PM UTC+2, Tom Kunich wrote:
This stuff is really expensive. But is it reliable? Looking in Craigslist shows a LOT of electronic groups for sale. Though they sure aren't going cheap.

The major question is: what need did they fulfill? Is there any cable failures at the pro-level? Any sticking gears or jumping gears that are attributable to the cables?

Well, on 11 speeds the rear derailleurs do have much better indexing. While the cable shifted groups index in the brifters, the electronic groups are indexed inside of the rear and front derailleurs. This makes it certainly more immediately available to the position.

But this would certainly be something that would work just as well with cable actuation and it would make the Brifters a whole hell of a lot cheaper though they would add the problem that like the electronic shifting you have to shift one gear at a time and with the cable units you can shift multiple gears at once with DuraAce or Record though not with SRAM.

With cables it would take two cables to operate in two directions or perhaps one cable pulled on both directions - sort of in a circle.

The advantage would be that you wouldn't have to plug the things in and as is usual, eventually this sort of stuff ends up on touring bikes that do not have the capability of charging anything.

My friend downloads European coverage off of the web and he says that he has watch many (not some) failures of these electronic groups. The one that I saw in person failed on the very first ride. He didn't tell me what he did but I haven't seen any failures since.

But even watching NBC Sports which pans away from failures, I watched two very obvious electronic shifting failures today alone. And on the other stages I have wondered why they were replacing bikes rather than a wheel without even looking at a flat.

I am sure that electronic shifting will get more reliable. But again - is there any advantage to it? There can't be more than 20 grams weight advantage to the electronic stuff.

I think the advantage of electronic shifting is difficult to quantify. Using it for 4 years on my crossbike and 2 years on one of my road bikes my opinion is:
- it is more convenient,
- it shifts quicker because of less travel of the switch/lever,
- it is more convenient in case of internal cable routing. Install it once and never worry about it afterwards,
- once adjusted never touch it again,
- FD shifts under load,
- the FD auto adjusts depending on the RD position,
- possibility of synchronized shifting.

Not for everyone this is reason enough to switch to electronic shifting.. Choice is good like Andrew always says, but electronic shifting proved to be extremely reliable and battery life is no issue. Personally I charge my battery once per season.

Lou

The rear derailleur in an electronic shifting bike has the ratcheting mechanism in the derailleur. This is both a positive and a negative. It would seem to me that high quality stainless cables designed in a circular pattern would work as well if not better than an electronic design and would essentially last forever with internal routing.

Possible. The shifter of the Rohloff hub has a circular cable.

As you probably saw in Stage 7, as one rider crossed the line he attempted to shift the front derailleur under load and it got caught in some intermedia position and he had to mess with it a second to get it into some gear so that he could cross the line under his own power. Looked to me like he lost a couple of seconds there.

Yes that looked very strange. I don't know what he was doing but as far as I know he dropped his chain and was trying to get it on the chainwheel again, but because it was so steep there and he had almost no speed it took a whil. He lost no time though because he front wheel was already past the finish line.


I don't think that battery life is really a problem but it sure as hell isn't "2-3 years". And you do have to admit that it is a source for a possible failure more likely than a cable.

2-3 years seems a long time to me also. I'm not afraid of a possible failure and don't suffer from 'black box' syndrome. If I rent a bike when I am on cycling holiday and cannot bring my own bike I choose one with Di2 if that is possible. I think Di2 is about convenience. Not a game changer but nice..


The auto-adjusting feature is a new one on me and that sounds clever.

What I meant was auto trimming. One feature I do use is the adjustment while riding. I have two wheel I use and they require a different adjustment. I get the system in adjustment mode by pressing a button while riding. I see my current adjustment on the display of my Garmin and I know that one wheel need an adjustment of +2 and the other -1. Like I said convenience.

Lou