ThermionicScott 

Even better: you'd save a little weight by having only one shifter.

seeker_moc

Personally, I'd rather have more cogs in the rear, but less up front. I have a 27-speed (3x9), but really, I only have 13 non-redundant gears: the 9 in my middle chainring, plus the 2 lowest on my small ring/ highest on big ring. I'd rather just have 1 chainring in front and 9 or so gears with a wider spread in the rear. It would be much simpler. As it is, I very rarely shift out of my middle chainring anyway.

Salubrious

I've been auditioning IGHs for the last 15 years. They are quite nice- I have had the Sram 7-speed, the Nexus/Alfine 8-speed, the Alfine 11-speed and the Rolhoff. Still not had the vision to build a bike with the Nuvinci.... yet.

The Sram, Alfine 8-speed and Rolhoff have great shifts, the Alfine 11 has a terrible shift (Rapid fire)- you have to wonder what they were thinking.

Hard to go back to a derailer system. I have 3 machines with them- a Guerciotti with all-Campy (mid 80s), an early 70s Paramount and a late 60s Sports Tourer. The Guerciotti works the best as far as derailers go but I spend far more time on the bike with the 11-speed hub. Its so much easier! No thinking about what and what to shift to get the right gear, faster shifting (progressive), positive shifting, the ability to shift whether the bike is moving or not.

The bike with the Alfine 11-speed weighs 20 pounds.

These days derailers have no appeal at all.

freeloader

Alfine Di2 was introduced recently, with both STI and flat-bar shifter if it appeals to you. The motor unit looks bulky and heavy. I think they can make further improvements.

bud16415

That’s the reason I went with the half-step triple 3 x 9. I get 21 of 27 gear combinations without any redundancy. You don’t have the bothersome one and a half step pattern of most triples. That is confusing if you are trying to get into that gear between two others. But by far the biggest advantage to something like I posted above is with the bigger ring being close in size to the middle ring the chain line on the smallest cogs is dead straight. I notice a bigger improvement in overall performance and smoothness in the tall gears with that straight chain line. I guess if there is a second bonus of running a half-step + granny up front is how smooth the half step shift is compared to the bigger jump of the one and a half-step. It’s as smooth as a cassette shift.
Here are the 21 of the 27 gear inches I use. The ones with the (-) sign are the big ring gear inches.

Granny (6 gears)
17.7
20.0
22.8
26.6
30.4
35.5
Main rings with half step (15 gears)
31.4
35.3
40.4
47.1
- 50.5
53.9
- 57.7
62.8
- 67.3
70.7
- 75.7
80.8
- 86.6
94.3
- 101.0

BlazingPedals

I know that's the theory; but modern materials can apparently fend that off. I have 9-speed wheels that have 20,000 miles on them and have never had a spoke touched on them. I'm talking about 26-inch and 700c wheels, not some 20-inch, 36-spoke wheel that you would expect to be strong.

BlazingPedals

Regarding gearing, there are several theories, or perhaps I should call them modes of operation. They're all valid for somebody, depending on their riding style. The way I use my gears is to treat the drive train as a 9-speed with normal, underdrive, and overdrive. Except for me, 'normal' is the overdrive. I tend to stay in the big ring unless I'm forced off from it. In my book, shifting chainrings is to be avoided because it's a slower shift - especially if I factor in the need to shift the rear at the same time.

Monster Pete

I think of half-step compared to a typical setup in terms of motor vehicle transmissions. The half-step is like a heavy truck gearbox with a 'splitter' overdrive. The main shift lever (rear derailleur) gives a whole gear change, the splitter (front derailleur) gives a half-gear change. You have the option to skip out gears if required by simply not using the splitter.

Compare this to an offroader with a high/low range transfer box. This is like a bicycle with the usual 'overlapping ranges' setup Typically, low range 3rd is about the same as high range 1st. You choose your range (chainring) to suit the conditions, then shift the main gearbox (rear derailleur) within that range. You wouldn't use the range selector very often, and in normal road use would very rarely use low range. The overlap between ranges allows you to minimise the use of the range selector (front derailleur).

bud16415

That’s how I use mine. (gear ranges in above post) If I was cresting a hill and was in 47 GI, I would shift in the back 54GI, 63GI, 71GI, 81GI and then if 87GI was what I needed make the easy front shift. Would require 5 shifts I would never think of doing all 9 and half being a double shift. People think of half-step being the old 10 speed days where you needed a chart taped to your bars and run the gears in order. Those steps were really big if you skipped the halves.

I was really amazed after I changed out my big ring how snappy a 42t to 45t chain ring shift is. I hit the brifter and have to look to see if it shifted it’s that smooth.

Nightshade

Very often for urban street bikes your setup in gearing is ideal with minimum fuss.

ThermionicScott 

Man, I really need to try half-step one of these days. I've got some 11-13-15-18-21-24-28 and 12-14-16-18-21-24-28 cassettes that I'm not using, and it would be fun to get all the range I need with small jumps. You have a good point that with modern cassettes, rear shifts alone aren't something to be feared anymore (since that's what we do mostly anyway.)