Am I missing something... it looks like the chainring is able to spin independently of the pedals, as if they moved the freewheel from the rear hub to the bottom bracket. Without that this would never work like he demonstrates. I've never seen the freewheel on the chainring/bottom bracket on a bike in the US, is this a common in other parts of the world?
I studied the video, and the only thing that I can conclude is that he simply unbolted the pedals from the chain ring. The pedals would therefore not be doing anything at all except support the rider's feet.
The site says "pedaling recharges the battery." This would require re-bolting the pedals back on.
It's hard to see angles that can really make this clear. Maybe there are some freewheels that let the chain ring spin independently of the pedals, which makes no sense to me.
>> it looks like the chainring is able to spin independently of the pedals, as if they moved the freewheel from the rear hub to the bottom bracket
IMHO that would be a safety hazard if they removed it from the rear hub. Without that, the chain will always be moving when the bike is moving. If your pants or anything else gets caught in there it ain't stopping.
Leaving it in the back AND putting it in the front as well is probably viable if a bit redundant.
No idea how the e-bike guys here did it but Schwinn had a bike for a while (my wife owned one) where the freewheeling was in the bottom bracket, it was called "FFS". It's pretty freaky and wasn't popular. You can see it in action starting at 0:30 here:
It's not common but you'll see it on some trials bikes.
I was always told that that is so you can use smaller sprockets front and rear for the same ratio, giving you more bottom bracket clearance when you're hopping about the place.
Obviously that's a very specific type of bike for a very specific purpose though.
Shimano Front Freewheel System (FFS) for a while in the 1980s. The only bike I know of that had one was the Schwinn World Tourist. I only know about it because I found a World Tourist in the trash and rode it for many years but with a different drivetrain.
There are other more modern systems with a crank mounted freewheel for enduro and DH bikes, allowing the rider to change gear while coasting in anticipation of a pedaling section. Similar to gearboxes, the idea comes back once in a while but never really takes off massively.
There was a french company named HXR components which used to produce that, I think they went bankrupt. Nowadays there is the Rocksteady Magic from boutique euro brand Intend:
https://www.intend-bc.com/products/rocksteady-magic/
