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This article by member @wheelbased got me thinking, what's a logical endpoint for the trend of electrifying bike parts?
What's your best guess? Assume it's NOT an ebike (and if you can figure out how to power an ebike without batteries why are you reading my dumb, cold medicine-inspired post?)
A few of thoughts below but I'm more interested in how it COULD be workable instead of my uninformed guesses. This isn't my field at all so please educate me!
- Piezo (as outlined in the patent article above), not a lot of power (not enough to run a solenoid or stepper motor).
- Something similar to a self-winding watch for each component? No idea if this is feasible, increases cost and complexity of each component but makes it easy to add components,
- Dyno hub? They exist and are relatively cheap and reliable, but require special hubs and a way to distribute the power to other components
- Use the fork or shock (similar to a wave generator). Could be drop-in (like a Diaz Runt or the Flight Attendant stuff) but still requires distributing power to individual components.
I assume the big S's are working on this, what can we come up with?
What's your best guess? Assume it's NOT an ebike (and if you can figure out how to power an ebike without batteries why are you reading my dumb, cold medicine-inspired post?)
A few of thoughts below but I'm more interested in how it COULD be workable instead of my uninformed guesses. This isn't my field at all so please educate me!
- Piezo (as outlined in the patent article above), not a lot of power (not enough to run a solenoid or stepper motor).
- Something similar to a self-winding watch for each component? No idea if this is feasible, increases cost and complexity of each component but makes it easy to add components,
- Dyno hub? They exist and are relatively cheap and reliable, but require special hubs and a way to distribute the power to other components
- Use the fork or shock (similar to a wave generator). Could be drop-in (like a Diaz Runt or the Flight Attendant stuff) but still requires distributing power to individual components.
I assume the big S's are working on this, what can we come up with?
My guess is something similar could be possible by using the rear hub to power a rear derailleur, after all, you only shift when you are moving. This is just a guess though, as I'm no engineer.
I wonder if it can be made small enough to fit in a jockey wheel/derailleur cage?
Another interesting concept I have heard is that in fighter planes they use special carbon layups in the hull that allow them to use some of the fibers as electrical wires for connecting equipment
Most self-charging watches these days use a solar cell because they're simpler and more robust, however even then the solar cell in Garmin's highest-end watches doesn't provide enough continuous power to keep its battery charged if the GPS radio is turned on.
I'm sure a solar cell could work well for something low powered and intermittent like a shifter, but AXS shifters for example get two years out of a CR2032 so battery replacement isn't particularly onerous.
The only problems I see with this are that the magnets and coils needed to make this work are not light. The mechanism is also very very similar to an electric motor so I doubt this would ever be legal in a competitive setting.
Of the top of my head maybe you could drive the fluid through a positive displacement pump rather than a valve and hook that up to a generator.
No wires and not having to recharge batteries feels like the goal, so given that:
- Fork, shock: damper-driven power generation
- Dropper: damper driven too, or maybe use the drop action?
- Rear mech: something driven off the jockey pulleys? (This one feels like the hardest to solve given how we treat derailleurs)
- Shifter: Piezo as outlined in the Shimano patent
My guess is all the components will need some kind of small onboard battery (w/ another way to charge it as backup) so at least the radio/Bluetooth will be available when the bike isn't being ridden.
I'm probably missing some really fundamental/critical pieces, what are they?
F1 uses MOOG valves to modulate rear brakes in order to keep the same braking distribution front-to-rear regardless of how much regeneration is done. It's a bit different to bikes (one pedal vs. two levers and all), but bikes are also much simpler.
Same for suspension, plus road bikes don't have suspension (can't say that anymore when it comes to hydraulic brakes though). At the end of the day a single system should be (would be) used for both road and mountain bikes.
A friend of mine a while ago asked why hasn't Shimano, given the wiring and centralisation of their Di2, made a spindle based dynamo with a small (CR2032?
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