JohnJ80

Big (enormous) leap here. There is a standard of performance in the automotive world. There is not such a standard in the cycling world. No one even knows what an automatic shifting bike drivetrain is. So how can you even make a statement like this?

J.

joejack951

Easily. Unless it can read my mind and filter out all of the bad decisions I might make, I'm going to be better off shifting myself. No computer knows my legs and lungs and riding conditions better than me.

To which 'standard of performance' are you referring anyway?

himespau 

I like the idea of the one lever up, one lever down that SRAM is trying. Get a triple up front and expand the idea so that it calculates where to shift both front and back to provide the next optimal gear in the progression (while skipping overlapping gears), and you'd have a winner in my book. But triples aren't "pro" (and there aren't enough tourers - who probably wouldn't want something they have to charge), so it'll never happen.

JohnJ80

No, this statement:
With respect to "standard" please even explain what an automatic shifting bike drivetrain is. Is it constant cadence? Is it constant power? Is it based on some terrain judgment? What is it? And the statement that someone who would have an automatic transmission in a car would buy the same thing in a bike? That's just nonsensical.

There are some nice advantages that intelligence applied to shifting has created. Shimano's latest mtb electronic group is an example. It picks the next gear to shift to up or down based upon where you are on the cassette and you just need an up or a down shifter.

So, yes, I don't see how you can make those statements.

J.

merlinextraligh

I'm betting you've never driven a car with PDK. Modern sports cars with computer actuated dual clutch transmissions perform better than is humanly possible with a conventional manual.

Not only does it shift faster, the ability of the transmission to know the right gear for the occasion is uncanny. It's a matter of a sophisiticated computer with inputs of a number variables, i.e. throttle position, steering input, braking input speed, grade, whether sport mode is engaged,etc. running a sophisticated algorithm.

It is amazing how a Porsche PDK knows the gear you want, without you even thinking about it. At least 99% of the time, it gives you the correct gear for the circumstance.

Given some time to develop the algorithm, there's no reason you can't develop the same thing on a bike, with inputs for cadence, power, speed, gradient, wind, heart rate, Fatigue (measured by TSS at the time, and/or hr drift), upcoming profile (from GPS mapping) etc. with input from the rider with regard to riding preferences, and the ability to improve the algorithm learning from the rider over time.

I think you're not really thinking about the possibilities in designing such a system, when you integrate all the data potentially available, and apply a fair amoun of computing power to it.

joejack951

Does it really matter? Any kind of auto-shifting feature short of reading my mind is likely to get it wrong at least part of the time for someone who cares what gear they are in. Someone who only rides at a casual pace really doesn't care what gear they are in, much like someone driving an automatic transmission car. They just want to move. I would tend to think most cyclists who do it for the sport do care what gear they are in. I know I do. We wouldn't have 11 speed cassettes if it didn't matter that's for sure.

See my explanation above.

See, I disagree. I don't want a front shift happening when I don't know it's going to happen, and I really don't want it happening along with multiple rear shifts either. That's not intelligent to me. That's getting lazy. I haven't used it so maybe it manages to perform that shift more smoothly than I'm imagining but that seems unlikely.

I've tried to use full 'auto' modes on both cameras and cars and they suck compared to me making the decisions. I don't see bikes being any different.

And just in case it isn't clear, I'm NOT against automation. Automating some tasks makes perfect sense when the cost can be justified. But for any decision that counts, I want to be making it.

JohnJ80

It's been demonstrated many times that it's almost impossible to do better than current cars with automatic transmissions with a manual transmission in either car performance or gas mileage.


Lennard Zinn seems to think the Shimano mtb setup works pretty well and he's not exactly a "casual" rider. He's forgotten more about drivetrains than most (if not pretty much all) of us ever knew. He said he was ready to hate it and turned out he loved it. Would I be off the mark if I were to suggest you've apparently never tried it?

Last time I checked cameras and cars bear no resemblance to bicycles. Just saying. You can't even tell me what an automatic shifting bike drivetrain is but you're sure that it's a bad thing and only casual cyclists would buy it.

J.

69chevy

So you can tell better than a camera's built-in light meter, the proper exposure time based on what you see?

joejack951

So the computer knows what I'm about to do? Amazing.

merlinextraligh

The Porsche PDK does.

Go down the highway in a straight line at 70mph, and gently lift your foot off the throttle, it will select neutral (or coast) to let the car coast saving gas.

Same 70mph, lift your foot quickly, tap brake, turn the front wheel in, and it will give you second gear, so you can roll on throttle quickly out of the turn.

With all the data available, millions of miles of experience put into developing the right algorithm to crunch that data, it can anticipate what you're going to do next, and the right gear to do it. It absolutely shifts faster than is humanly possible, and it makes better decisions, than the vast majority of drivers.

If you don't happen to like the decision it makes, you can shift it yourself with a flick of a paddle, however, the only real reason to that is to play with it.


Same sort of algorithm, can do the same thing for a bike. you're just not opening your mind to the possibilities.

merlinextraligh

Well, the answer to the light meter is yes, you can do better, in certain circumstances, than blind reliance on the camera's meter.

In order to get the proper exposure for a scene, the camera has to know how bright the scene is in reality. To do this it assumes the world is 18% gray. This works pretty well because the reflectivity of the world averages out to be 18% gray. However, for certain subjects (sun in bright light, white sand, black dogs, etc.) it doesn't work very well, and you have to compensate.

So spot metering off a gray card, or off a small portion of the scene which is 18% grade, or just adjusting exposure up or down based upon accumulated experience, you can do better than the camera.

This was very important shooting slide film, which had very low exposure latitude. With digital cameras, and shooting in RAW, where you can adjust exposure after the fact to a pretty good degree it's less important. But there are still times, you want to spot meter, or just use exposure compensation, to tweek what the camera's telling you.

JohnJ80

Agree. But a camera is not a bicycle. So it doesn't really apply.

J.

joejack951

Links?

I did say I've never tried it. Sounds like I should.

Not taking the time to describe the system that I don't think would work as well as me just doing it is different than being unable to tell you. Look at merlinextralight's thoughts. Complicated as hell just to replace me pushing a button. No thanks.

69chevy

So what you just said is that most of the time "auto mode" is perfectly fine but sometimes needs a little tweaking.

So why does it "suck"?

joejack951

Never said that. What I alluded to was taking control of at least one parameter rather than shooting full auto. Typically I shoot in manual mode with auto-ISO on. This lets me specify aperture and shutter speed while the camera decides on the brightness. When the camera gets even that wrong, I have exposure compensation (incorrectly named for how I shoot but that's besides the point). The fact is that I know way better than the camera ever could how much depth of field I want and what shutter speed I want. I'll let the camera decide on the latter when it doesn't matter (bright sunlight and shooting medium to wide apertures) but that's about it. I do shoot full manual when necessary, too (studio lights).

joejack951

For less engaged driving, it sounds fine. I still can't see it anticipating (it simply can't) what I want to do next in enough situations that I'd be happy to just let it do its thing.

Or to simply be more engaged in the process of driving. Regardless of the slowness of manually shifting (real manual shifting) a car, I'll still always prefer it to fully automatic just because I'm more involved that way. Semi-automatic with a dual clutch system could be fun, too.

Do you truly believe cyclists would benefit from all this or are you just arguing for the sake arguing?

69chevy

And... What I'm getting at is that although you pride yourself in being smarter than your camera, you rely on it's automated metering.

Auto ISO, is still allowing the camera to do the thinking for you.

Depth of field and shutter speed choices are personal, but the camera will still pick an accurate exposure much faster and much more accurately than you could with a fully manual camera and no light meter.

merlinextraligh

Its actually for more engaged driving when its comes into its own. 10/10ths on the track, you're fully engaged, and knowing the car is going to be in the right gear is one less thing to require attention, when you're concerned about brake points, turn in point, apex, and exit point.

It's driving 6-10ths on the street where shifting your own is fun, if not the fastest answer.





Never said a manual transmission isn't fun and engaging. My point is computer actuated dual clutch performs better. For driving on the street, not racing, I definitely like a manual transmission. But there's no getting around the fact that from a performance point of view, its slower.



Yes. For the casual cyclist it will make cycling less intimidating and more fun. You'd be amazed the number of new or occasional riders who are intimidated by shifting.

On the high end, a computer controlled drive train that sequentially shifts through the ratios (making front and or back shifts as necessary) that can appropriately execute dual shifts, and multiple ratio shifts flawlessy and immediately, that is programmed precisely to your preferences, that know exactly how strong you are at the moment, that can read upcoimg terrain, and is dialed into your preferences, with the option to put it in full manual mode, or semi manual (where its shifts but you can override), would be a step forward, very similar to the dual clutch transmissions that are now taking over in Ferraris porsches and lamborghinis.

JohnJ80

[QUOTE=joejack951;18323477]Links?

Why Automatics Are Catching Up In Fuel Economy And Performance

And google is your friend.

On top of that, while they are equal to marginally better now (automatic over manual), that trend will only improve. All the R&D time and money is going into automatics and it's getting hard to even get a manual anymore. Single digit market share percentages, IIRC.

Besides that, at 6 or 8 speed transmissions, who'd want to shift that by hand? If you want to get the performance and fuel economy out of the car, you'd have to be doing that with a manual in order to keep pace with automatics. That would be a serious pain to drive.

Don't know, depends on what you want. But I would just suggest that you might want to re-think the blanket statements. "Never say never" and all of that. In the traditionally conservative bike world, this stuff starts out at the high end and percolates down the food chain. High end buyers are discriminating and are a pretty cruel test of if something works or not. Perfect example is Zinn and the Shimano Di2. Other examples are the dissing that electrics and specifically Di2 got when it first came out. Now the vast majority of the top end peloton is on electric shifting. Same thing was true for index shifting back in the '80s. You would have thought it was the end of the world to listen to some to have indexed shifting on your bike. Now, everything is indexed and it's great.

By way of example, my Di2 system on my main road bike is incredibly reliable and it's definitely more complicated than the Mech system I have on my other bikes. But I don't ever have to adjust it as the cables stretch and all the time I've ridden it I have *never* had a bad or partial shift as I would have had (and do continue to have) with my mech system. So complexity is not a problem if it brings benefits such as reliability and usability. That looks like what the Shimano mtb Di2 is doing.

If you don't want complexity, then you should be looking at less complex systems like a single speed. But, of course, it's not that simple. It's not just all complexity or all technology. It's always a set of tradeoffs.

In arguments like this, often it's more a case of what's familiar over what isn't that is the hangup. In the case of a lot of this, at least in a competitive sense, it can also represent an advantage. Di2 has been one such issue. So did all the aero things that the peloton dissed only to lose the tour to the guy that had it (Lemond over Fignon). Because most of this stuff comes in at the high end, it's generally a good idea to keep tabs on it and an open mind.

J.

rpenmanparker 

Here is one article from Edmunds that talks about comparative fuel economy of automatic and standard transmissions as well as other myths. Five Myths About Stick Shifts: Manual vs Automatic Transmissions on Edmunds.com

merlinextraligh

Ferrari no longer makes a car with a manual transmission.














[edit brain fart]

hueyhoolihan

not surprised. it's an abomination on a sports car. ...er, IMHO.

now, if they come out with a station wagon, well, i guess, it would be okay.

merlinextraligh

sorry, screwed up my post. they don't make a car with a manual. they are all computer actuated automatics.

and they do make the FF, a flying brake/station wagon.

.

hueyhoolihan

i was watching the Brazilian Formula one race on Sunday and i'm sure, pretty sure anyway, i saw Ferrari's Vettel and Raikkonen, and everybody else for that matter, shifting their cars by hand, it was from the steering wheel, probably no clutch, was fast and there may have been a lot of shenanigans going on in the transmission too, but i don't think it shifted until they wanted it to. unlike a true automatic. at least the one's i am familiar with.

and the FF? well... i was thing more along the lines of this...



and this...



and like the one we had ('60 Ramber) when growing up... it had a three-on-the-tree manual.

JohnJ80

Exactly.

"The manual transmission has become kind of a dodo bird." Share of market is only about 10% now and dropping. Fuel efficiency is now neutral with manual transmissions or better with automatics. In a few years, when all transmissions will be 6 speed or higher and fuel efficiency and performance will be better, they won't be offered in new cars anymore. In order to have similar efficiencies manuals will need to have at least 6 speeds. Imagine shifting that.

This is all over but the smoke. In some ways, kind of sad but the ride with an automatic is superior in every way.

J.