Originally Posted by rpenmanparker

Also, pedaling isn't nearly as uniform as controlling the throttle on a car. If you slack off for a second for any reason, grabbing a water bottle, dodging a pothole whatever, is the transmission going to downshift mindlessly? That could be very disconcerting and inconvenient.

Originally Posted by donrhummy

One big benefit from this: if the Ant+ receiver records your gearing at every pedal stroke, training apps will be able to tell you which gearing allows you to put out the highest power with the lowest effort at different gradients.

Originally Posted by RPK79

Data overload.

Originally Posted by spectastic

Mechanical cables are still the most reliable and cost effective way to shift gears on a bike, and I don't see that changing any time soon.

Originally Posted by donrhummy

for most amateur riders, yes. but what about pros or coaches?

Originally Posted by WhyFi

Cheaper? Yes. More reliable? Depends. Whether electronic or mechanical, upkeep will be necessary and that will rely upon the end user. Some people are more comfortable charging/changing a battery, some people are more comfortable adjusting tension and limit screws.

Originally Posted by jeff_l_scott

This is all done for shift feel, and the biggest reason to do it is due to the torque spike that would otherwise occur. The torque spike is due to the fact that during an up shift the transmission is effectively decelerating the engine from its speed in the lower gear to the equivalent engine speed in the higher gear. The engines rotational inertia has to go somewhere, so the basic objective is to reduce engine torque output by about the same amount as the deceleration of the engine will add.

Also, it's not like this is a necessity. Automatics have obviously been around for much longer than the ability to electronically reduce engine output. This is a nicety, not a necessity.



Given the rotating inertia's involved, I don't think it is an issue.

Originally Posted by RollCNY

And as to knowing what gear you are in for maximum power, that wouldn't seem useful without knowing grade, and what your shift pattern was prior.

Originally Posted by bt

your in luck, only the battery has to be charged,

Originally Posted by Campag4life

To put a finer technical point on automatic shifting which exists on current motorcycles and automobiles, there is greater opportunity for electronic synergy between the engine and the trans than would be available on a pedal power road bike. The way it works with lets say for a current automobile is...when a shift is about to occur as engine RPM and road speed increase based upon load and engine vacuum, throttle position is electronically closed fractionally and ignition timing is ********ed slightly to 'soften' the shift. This dramatically improves shift quality and gives it a more seamless quality. Automatic shifting on a bicycle will be more challenging because rider watt output can't be tweaked as readily as with an electronic motor or gasoline engine. Some accommodation could be made with a fluid coupler or torque converter to soften shifts made under rider load but of course this would reduce power efficiency of the rider to the road. If a rider doesn't know when a shift is coming, then a rider isn't going to reduce power to make the shift more seamless.
Will be quite interesting to see where this will lead.

PS: noted technology will likely also affect the wire harness on future electronic shifting groupsets. Wireless shifting is like part of this architecture and therefore amount of wire stringing won't be as invasive....not unlike wireless bike computers taking to sending units that are not connected with a harness.

Originally Posted by RollCNY

How would an automatic bicycle ever know which hill you want to power over, and which hill you want to spin? How would it know when you want to attack? If you have to manually override in every aggressive situation, it would seem silly to not practice for that aggressive situation with every easy shift, much like we do know.

And as to knowing what gear you are in for maximum power, that wouldn't seem useful without knowing grade, and what your shift pattern was prior. Most folks would be putting out their highest wattage in their little ring, because that's where most gear user's are when they climb. Seems like an easy way to get garbage information. Just email me, and I will give you garbage information for much less per use.

Originally Posted by donrhummy

One big benefit from this: if the Ant+ receiver records your gearing at every pedal stroke, training apps will be able to tell you which gearing allows you to put out the highest power with the lowest effort at different gradients.

Originally Posted by RPK79

No matter how fancy the programming is that goes into automatic shifting bikes they will never be able to beat the data crunching of our own brains and bodies when it comes to when to shift and what gear to be in at any given time. It's a solution in search of a problem.

Originally Posted by WhyFi

If we're talking about the short-term future and experienced riders, I'd tend to agree. But if we add inexperienced riders and extend the timeframe a little, it could be very beneficial for some. A couple years ago, I went for a ride with a friend - an avid swimmer and runner that had recently gotten in to triathlons. She couldn't shift her way out of a paper bag, despite being very in tune with her body's limits. Simply having me there to say, "hey Nik - try shifting in to the big ring up front," or "try going two clicks down on the rear," was a tremendous help for her.

Originally Posted by RollCNY

I'd like a system that repeatedly says, 'Your door is ajar". I would pay extra for that.

Originally Posted by WhyFi

If we're talking about the short-term future and experienced riders, I'd tend to agree. But if we add inexperienced riders and extend the timeframe a little, it could be very beneficial for some. A couple years ago, I went for a ride with a friend - an avid swimmer and runner that had recently gotten in to triathlons. She couldn't shift her way out of a paper bag, despite being very in tune with her body's limits. Simply having me there to say, "hey Nik - try shifting in to the big ring up front," or "try going two clicks down on the rear," was a tremendous help for her.

Originally Posted by RPK79

Sounds like a crutch that would keep new riders from ever achieving their full capabilities on the bike since they would be limited by what gear the bike feels they should be in. Maybe beneficial in the short term but at the same time not so much.

Originally Posted by WhyFi

I don't disagree with your analogy, but I don't necessarily agree with your conclusion. Where you seem to think of a crutch as a permanent solution, I'll point out that they're often temporary aids. For people that are unsure of when and why to shift, I think that it could help them explore their potential and help dramatically shorten the learning curve.