Brainstorming: Pedal Assisted Electric Scooter

[NiHaoMike]

John's Stuff - Toyota Prius Education - Power Split Device
That's how eCVT (HSD) works.

[Frank Lee]

Where do I buy one for my electric bicycle?

It doesn't look easy to build to me.

[Frank Lee]

Originally Posted by papaslides

I don't know the mechanics of it, or how to imagine such a gear setup... but the idea is that the pedal assist is only in first gear to add some extra torque to that first push (or to take some of the heavy lifting off the motor for going up hills, so maybe gears 1 and 2). Then after that the pedal would stop aiding the motor and really only act as a pedal powered charger for the batteries. The other inspiration behind that function is the idea I posted about it having a "neutral" gear specifically to function as a pedal operated power generator (like those exercise bikes you can get plans for online that generate enough power to charge cell phones, run laptops/tv's etc.). The idea was that at home in the garage it could function as a pedal powered generator, and could be taken out as a commuter/errand running bike.

So obviously the scooter frame is a dead end, but I'm concerned that starting with a mountain bike setup will not be big enough to support the batteries, engine, and possible cargo space in the future. So if a mountain bike isn't beefy enough (IMHO) and a scooter is ergonomically insane for this application, what's next?

If it was my project I'd make a separate, stationary garage exercyclegenerator just for that purpose.

I also think that it doesn't take a whole lot for a battery pack's weight to overwhelm a bike's capacity (especially in my case since I already take up so much of the bike's capacity myself! ). I like the idea of a pusher trailer for that reason.

[NiHaoMike]

It's easier than it looks. Just two brushless DC motors and a planetary gearset. Then add two 3 phase inverters with a microcontroller.

[Frank Lee]

I still don't know where to buy that stuff and how to marry it all together. Does someone have one I can copy? Are there plans?

[NiHaoMike]

No plans yet. It's an idea I'm thinking about building. Maybe someone else will build one first.

[Frank Lee]

papaslides will!

[papaslides]

Wow lots of ideas heh. Perhaps you're right, my idea for an all in one omni-cycle might be too ambitious and not very realistic. The reason why I didn't want to build a separate exercise bike generator was because the cost vs. gain in terms of savings on power was pretty insane... something like 50-100 years of using it for an hour every single day until it paid for itself, green yes, economical no. Now if that cost was for a daily use electric vehicle that could double as a pedal powered generator in its spare time, that gives it a much different cost effectiveness in my mind.

[captainslug]

A top speed of 35-40 and a range of 25-30 miles is just not achievable in a form factor that would be compatible with pedaling.
You will need a rather sizable pack of batteries (2kw or more), and a minimum of 2kw in motor power.
All of that extra volume and weight will make pedaling difficult.

[NiHaoMike]

On flat land, weight itself has no impact on power needed to maintain speed. The top speed can be increased with aerodynamic modifications. Since it's a hybrid, acceleration is not much of an issue. The eCVT can even be programmed to measure pedal power and add a given amount of electric boost to make it feel very light. The possibilities are endless with a software-defined hybrid transmission.

Such a bike can be put on a stand to generate electricity and the measured power output sent to a computer. It would also work as an interesting controller for a racing game. When riding the bike normally, data can be recorded in real time to a SD card.