Auto transmission on a bike may work for those people that find shifting too complicated. Seems like a pretty small market.

Automatic transmission on a bicycle = solution for a problem that does not exist.

I can understand that. Can't beat anything that causes a smile.

As many others have said, who really cares if an automatic is a couple of tenths quicker over a distance? Do those tenths actually make it a more enjoyable drive? Can you even notice them from the driver's seat? What you can notice is how much more boring the automatic makes the drive. I can only imagine those drivers who don't like to actually have to work a clutch pedal and gearshift will be overjoyed when they can buy a car that automatically takes care of those other boring tasks like turning and braking. "Look, my car is two seconds quicker over that three mile course and I don't have to do anything - just sit here in the seat! Isn't technology wonderful?" A properly executed heel and toe downshift is rewarding. Having the car do the work for you is boring.

Back to the subject of bikes, what about a CVT drivetrain? The rider would have some sort of control to dial in his or her preferred cadence. and the bike would vary the gearing to always keep it there. It would be like a fixie/SS but you'd have an infinite range of gears. Have everything done in the rear hub, and a single chainring. If you're going to make gear shifting automatic, I'd prefer something like that.

This is such an interesting line of thought for this reason: it defines one of the "there are two kinds of people" situations. If you think this way, then your beliefs make sense. If you believe the opposite, then they are ridiculous. Driving is not entertainment to me. It is not a sport. It is not a competition. Performing the activity provides neither satisfaction nor a sense of accomplishment, no matter how well it is done. I am not bored by automatic shifting, but neither am I entertained by a stick shift. I understand how this differs from you. I know that there is nothing that makes you a better driver than me, just because you like to drive stick. I also know we will never agree, because there is nothing real in this debate. No advantages, no disadvantages no matter how many statistics are quoted. It is all just two different attitudes. That is what makes the world go 'round.

Your comment about "properly executed heel and toe downshift" though is very eye-opening to me, because there is one area where I am guilty of the same line of thought you have expressed. Having grown up in an old city, New Orleans, I am a master of parallel parking. I recognize the similarity between how I congratulate myself for a good parking job and what you said about shifting. Yes, actually I recognize how silly I have been. I don't have a car that automatically parks itself at present, but likely will within a few years. Seeing how foolish it is to care about such mundane and easily learned skills, I am determined to use and enjoy the automatic parking feature when I get it. Always moving forward, never backward!

You and many others characterize this kind of thing as a crutch for the lesser cyclist. It would help someone who is incapable for sure. But its appeal won't be limited to that. Wait and see. Some day it will be introduced. Some time after that we will all be surprised by how well it works. Racers and their imitators will resist, possibly for good reasons. But it is coming, and it will be very popular.

I guess I'd see hills and obstacles as the biggest problem because car engines don't tire in the same way I do. With a car, if the automatic controller gets a shift "wrong" because it doesn't know I'll be changing grade in 30 metres, it just shifts again on the hill and the engine doesn't care that it has to put out high rpm's for a bit. The car engine will be as fresh at the top of a climb as at the bottom. The car's automatic doesn't even care how long it puts out higher rpms. It doesn't even need to know if it is a long hill that gets even steeper further on, or, on the flip side, that I am about to jump out of the saddle just before the top of the hill. So, I'll be needing Predictive Terrain Detection (tm).

And maybe some yaw and roll sensors for turns.

I was thinking it will be helpful around town (or when tired at the end of a ride). It would, of course, need to know when a stop is imminent and shift soon enough that it can get to the right gear for starting. Either that or the nature of the drivetrain (i.e. inability to shift standing still) might have to change.

Exactly. And, on some cars, like my Prius, there ain't no gears to shift. :-)

You mean something as crazy as a shaft drive bicycle?

Dynamic Bicycles - Chainless Technology

This is based on a totally different premise. It is hybrid of sequential shifting, not really automated shifting. It's is a mode to make the transition from one gear ratio to the next more even in certain situations. Shimano Synchronized Shift puts all the control into one shifter instead of two.

Who will benefit from it, and in what way ? I suppose casual riders riding around town might like it, even if they are comfortable with shifters. But anyone who actually cares what gear they are in will not want to be told what gear to use.

I'm imagining how much it would suck when that really steep part of the hill comes up and the bike hasn't shifted prior (like I normally would) but shifts a few seconds into the effort. I would be super pissed for those few seconds.

Saw a pretty brand new 392 Challenger the other day...

The moron stalled it 3 times at a light...

How do you stall a 470hp, 470 ft/lb car on a flat road???

Anyway, bicycle automatic, it can't tell what the input curve will be like. Tired, sore from leg day... feeling on top of the world...

All will have the same shift points.

No thanks.

Uh, you do realize that the product in the vid was integrated with a powertap hub?

People have been working on this but their main problem is getting the weight down in the rear hub where this transmission is located. Cycling | Fallbrook Technologies Inc.
You can buy one and try it for yourself.

As I said earlier, I rode a 3-speed automatic cruiser bicycle back in the early 80's. Fine for flat roads where one would usually ride a cruiser. Not so good on hilly dirt roads.

The Dancing Chain has pictures of automatic cranksets

http://www.os2.dhs.org/~john/bilis.jpg
And there's been the 2-speed Fictel and Sachs and Bendix hubs where you back pedal to shift gears for about 100 years now, IIRC.

Sounds like the same conversation about electronic shifting 5 years ago.

Doesn't matter really. Henri Desgrange was right. Changing gears is for swissies.

Already exists. Search for Nuvinci 360. Pretty interesting, I keep looking forjust the right bike to put it on.

Now, if they made a fixed gear CVT, that would be interesting...

I like the idea, based on the video only. It's obviously a natural progression or merge between power meters and electronic shifting. Plus, if you want to override, just shift. Albeit that does kind of defeat the purpose.

I can't afford one, but I could see myself using it for flatter roads with small rises, and downshifts for accelerating out of corners. Likely I'd choose when to shift on a more serious hill.

Even if I never get to use or try one, I think it's *****in'.

How will that help ?

I could be riding at 20 mph putting out 200 watts in a 53 x 16
Tomorrow, exact same road, speed & watts, but I feel like spinning a bit more in the 53 x 17

Every ride is different based on mood, goals, fatigue level, and can chage during the ride.

You certainly can store in a computer your "type" of ride and the transmission can adjust accordingly. You feel like spinning? Punch in the spinning program.

Seems like a lot of effort to just avoid throwing a lever, or pushing buttons to shift.

If it isn't seamless and doesn't just work without input, I don't see the advantage. I know when I'm out on a ride I use a high gear or low gear depending on how I feel right that instant and can't see a bunch of electronics figuring that out better than my brain.

Yeah, but no way to sense 1) my intent, nor 2) my desired power delivery. Sometimes at given output I want 67 rpm, others 90 depending upon what I feel like at the moment...

Just torqued up a big hill? I wanna spin... Just spun out, then a nice low cadence whump, whump, whumo...

The nuvinci loses at least 15% AT IT'S MOST EFFICIENT RATIO!... Some ratios were GREATER THAN 20%!

Like dragging your brakes!

A derailleur system looses what 7%? Based upon fixed gear loosing like 6%, and the boggies for the derailleur pulleys can't add that much drag... Saw studies on replacing the bushing based pulleys w/ high end bearing ones having an effect that could not be felt.

So at best DOUBLE the drive train loss?

And it is REALLY heavy, feels like a decent pack on the rear...

Chain would have to be in truly horrible shape to match that..

For the supposed gains, and engine loves continuously variable step-less ratios.. There is 1 optimum place for output at given output, maybe some ranges might have 2 with v-tech or a few with variable valves, but that's it...

But leg muscles are profoundly flexible in their output.
For most outputs (especially in the sustainable ranges) you can deliver a given power output in a wide range of rpm...

exactly, though I'm pathetically lame so it's mostly fatigue... I get a lot more mileage in a day than I should by switching to different cadence patterns when I trash one... Most times spin at ~80, sometimes ~65-70, others 70's... and occasionally 90's...

Wipe one out on a hill, no problems change up cadence pattern.

here's the test ride video and eval


https://www.youtube.com/watch?v=FCNR...AltZBW8so1NFKZ

As I mentioned earlier, I understand and appreciate that view. But here's another.

Many automatics don't take away from that same driving experience. I can shift gears very quickly and responsively from either the shift levers or paddles. From that point, the transmission picks out the right gear and shifts faster than just about anyone. So if you seek performance, this is hard is hard to match. Except for doing heel to toe foot action, the automatic takes away nothing and makes improvements. I can still shift whenever I like and it's quicker.

The other thing is manuals don't often work for me. My commute to the office takes 45-60 minutes for 11 miles. The automatic allows me to drink coffee, eat, and whatever.