tomato coupe

I didn't buy electronic group sets for any of those reasons. I bought them because they shift faster and more precisely than the best mechanical group set.

Koyote

I completely agree; that was my thinking when I wrote " I don't think my Di2 bike shifts any better than my mechanical Shimano bikes. It does offer some nice capabilities, but nothing essential."

Though it seems that many (perhaps most, from what I've seen) Di2 owners do think that it shifts better than a perfectly tuned mech group, that's not been my experience -- but Di2 does have all of the other positive attributes that you mentioned. In fact, I'm not sure that I will ever buy another bike with a mechanical groupset.

Koyote

I'm not sure you've ridden a good and well-tuned mechanical groupset.

cuevélo

That is unlikely to ever be suggested by Shimano. The shift aids (Hyperglide features) of each cog is designed to work with are angularly oriented relative to the cogs and shift aids on either side.

WhyFi

Are you insinuating that, for instance, a 16t on a 12-25t might be different from a 16t on an 11-32t. I would doubt that very much.

Sy Reene

Actually, though no idea if this is because of what was claimed.. the part number is different:

WhyFi

Huh, cool. I'd be interested to hear how much of a difference it makes in real word shifting performance. I wouldn't think that it would be that much, but then again, going by the chart, it looks as if Shimano has gone to the trouble of making at least four different 19t cogs, which seems a bit much unless it's going to have a meaningful impact.

cuevélo

Not all cogs will be different; it depends on how things line up. But there will be some different cogs.

Apparently it makes enough difference for Shimano to spend the time and money making multiple different cogs. It doesn't seem to be something that is just for marketing, as not many people are aware of it.

Bah Humbug

I think even their chainrings are specific (the 36 for a 46/36 is different from a 52/36). They’ll work mis-matched, but some degree less so.

Sy Reene

My guess is, if it's an alignment/angle thing, that variations exist depending on how many tooth differences there are in the cassette to the next lower cog, and/or also the next higher, or something like that. In combo depending on eg. if the 19T is the 7, 8, or 9th cog in an 11s cassette.

To use a picture, the teeth align with the drawn red line, but this is not parallel to the freehub, they are at a specific angle. Easy to imagine removing any given cog, and pushing the rest to close the gap, and that red line would get jagged, unless the appropriate angled cogs precede or follow, etc. How much it matters with actual shift performance, I'm unsure.

tomato coupe

I've owned most Shimano (105, Ultegra, Dura-Ace) and Campy (Athena, Chorus, Record, SR) mechanical groups. I still ride SR-11 and Chorus-12 mechanical groups. They are very nice, but the electronic groups I own (Record & SR EPS) offer quicker and more precise shifting. And, they do it with very little effort, under heavy load, and in wet dirty conditions.

Koyote

I very much agree with the part in bold, so that is certainly an advantage.

Seattle Forrest

There was a thread recently about Di2 where a surprising number of Di2 owners said their electronic bikes didn't shift any or much better than their mechanical bikes. Most of them said they wouldn't go back for other reasons. Anyway you said you were in a very small minority about shift quality and I don't think that's true. My last Ultegra (mech) bike shifted perfectly too. Maybe we need a new thread with a poll.

Koyote

I must've missed the thread to which you are referring...Wish I had seen it. When I have expressed my sentiments in at least one other thread, I got a lot of pushback.

But I do agree with you that Di2 doesn't drift out-of-adjustment the way a mechanical groupset will over time, and I love love love the gearing readout on my computer.

I think my fave thing about Di2, though, is having two fewer cables cluttering up the front end of my bike. That, along with the bar-end junction A box, makes for a super-clean looking front end.

Kimmo 

I hate to jump on board the derail, but this is the opposite of my experience.

With the possible exception of fiddly oddball chainstay calipers or whatever, rim brakes are an absolute piece of piss to sort, unless perhaps you're trying to eliminate squeal on a hybrid, where lack of quality, and the geometry of the whole system is apt to conspire against fixing it.

Issues that can crop up with discs, although not hugely common, aren't limited to poor quality gear, and can prove to be painful time sinks due to the fine tolerances involved and the fact that much is hidden from plain view. I'd like to think that some of the dumber problems like poor caliper mounting point alignment were down to teething issues, but can't confirm since I haven't been working as a mechanic for a couple of years...

tomato coupe

Is "piece of piss" good or bad?

mstateglfr 

haha! example of language being the same but different.
in the post he is saying rim brakes are easy, but that term sure seems like a negative one.

Kimmo 

You could also do it in the Uniglide days of the cassette era.

But I understand why it went away; with proper tooth profiling, cogs have to be shaped to go next to their neighbours, which makes mix and match complicated and ultimately impractical when you'd have to stock 3 or 4 versions of each cog.

All I want is a decent selection of ratios, and you'd think cog proliferation should make that easier and easier, but nooo. I've gotta have a useless to me 11t, and soon 10t will be impossible to get away from. I have no idea why 11s 12-27 isn't common as mud, since that perfectly suits the type of riding lots of cyclists continue to do.

But instead of having something that works beautifully for 99% of stuff, folks have gone for something that works okay for 100% of stuff. Seems dumb to me.

Kimmo 

As in, piss-easy. (Phrase obviously wasn't coined by an old geezer)

WhyFi

Yeah, I know - you drop in on this subject regularly. Your experience isn't typical... and I'm not speaking about good/bad experience with rim/disc, I'm talking about your experience working on bikes. For someone that's been working on bikes for ages, I've no doubt that rim brake problems are easy to sort out. For someone that's not as familiar with them, they can be fiddly, temperamental, and frustrating and they can spend much of their time working suboptimally.

Kimmo 

Oh, it's meaningful. BITD when I ran a 7s Shimano cassette and Ergos with a Campy RD, I cobbled together a 13-20 using MTB 18 & 20, and the shift between the 17 and 18 was junk; worse than plain cogs IIRC.

Seattle Forrest

Windows is so easy to use because it's kind of dumb and just does what you tell it, Android is a completely different kind of dumb where it's constantly trying to guess what I want and usually getting it wrong. I need to attach a pdf I signed to an email, in Windows I could just point to where the file is, on Android it keeps offering images and audio but won't let me go to a file browser.

Of course we're both more comfortable using the technology we grew up with.

Bah Humbug

When I see recommendations to use a blowtorch on rotors to clean off contaminants, I have a hard time taking that seriously.

So of course I was down at the shop over lunch talking about a Topstone.

tomato coupe

Upcoming Di2 is going to be Windows based? We'll have to redefine what it means to crash a bike.

sfrider 

It probably doesn't matter at all. There seems to be one point where they line up, and the rest are staggered due to there being more teeth on bigger cogs.