Automatic Gears

[Dogtrousers]

have you tried explaining what cross chaining is to someone who really doesn't get it?

Definitely not. I never will, either.

I'm probably missing out, I know.

 

[Bollo]

I have been thinking on this well before this thread popped up.
But the 'change gear' catalyst is mainly either post or pre a drop in cadence.
The Enviolo system (as referenced above) uses cadence as the independent variable which the rider sets.
I envisage electronic shifting with a protocol which shifts to an easier (or harder) gear when the rider's cadence drops/exceeds a range (specified and input by the rider) say 75-90rpm.
Increased or decreased torque (not power) would 'merely' mean the speed goes up/down.
Maybe there are systems (adaptions of eTap or Di2 assumed) that do this - please point/link to any.
A manual (bars) overide would seem advantageous so the rider can, for example increase cadence while maintaining torque in anticipation in the immediate approach to a hill, and vice versa. Not sure how freewheeling would be dealt with: perhaps if the rider freewheels, the default is no gear change till x seconds after resumption of pedalling.

It would be possible with an electronic system using some ruleset based on torque and cadence.

Issues are….

There’ll always be a scenario where you’ll curse it to buggery, for example if you’re fatigued.

Unexpected shifts could lead to some crunching and at worst wobbling under high torque. You could imagine an upper limit on power that requires a manual shift only. I have my SRAM AXS set up to autoshift the front derailleur so I just have to go ‘up’ and ‘down’, but I wouldn’t want to use it in a crit or similar. I’ve got to the stage where I can feel when a big ring change is going to happen on a shift, but it can catch you out.

Shimano will take you to court (see Hammerhead’s removal of Di2 shifting reporting). I think SRAM eTap uses a custom Bluetooth protocol which in theory you could reverse engineer, but I don’t know if anyone’s tried it. This is one of my big criticisms of electronic gearing - for many reasons (3rd party support, longevity) this should be an open protocol within the Bluetooth or ANT+ ecosystems.

One other option that I’ve considered for giggles is coding up something that just recommends an upshift, downshift or optimal gear. Part of the reason I bought a Karoo 2 was its openness as it’s based on Android. It’d be an interesting project. Have I done anything about it? Have I flip.