[jayrot]

Anyone particularly excited about this concept might be interested to know that it already exists (for a little less than $400).

PikaBoost[1]

It works. But not nearly as well as an ebike, of course. Here's a youtuber doing a fairly in depth review and test of one [2].

[1]https://livall.com/products/livall-pikaboost-2-electrify-you... [2]https://youtu.be/m_wVzoNrDL8?si=gCwvHZgrsV3klZ49

[prmoustache]

There is also that extra small friction system from velogical which has the advantage of allowing you to use a mudguard: https://www.velogical-engineering.com/velospeeder/product-in...

[yallpendantools]

I'd have to forego my saddle bags and maybe my mudguard for that one.