That looks like a fun disaster waiting to happen.
Just wait until someone’s shoelaces get tangled up in the not one, but two chains!
Even ignoring the obvious shoelaces or stick or whatever, chains themselves will eventually wear out or become damaged too.
So, imagine riding that bike, and one of the chains snaps. What’s it gonna do?
If you guessed it’ll pop and get tangled in the other chain and cogs and still fuck you up, well have a cookie!
Not saying you’re wrong, but I’d think this lowers the chance of breaking a chain by adding a hill climb gear, at last compared to the previous model.
Still, chains wear out and become loose and ‘stretched’ over time, and can and will flop around and sway a bit. More so as the chains get older and worn out.
On the bike in the post, there doesn’t seem to be any automatic chain tensioner, so as those chains wear out and loosen up more, they can and likely will sway enough to bump into each other.
When you consider the already existing hazards that can cause a chain to break, it seems to me this just adds more potential failure points, plus a failure mode where the chains can interfere no less, which isn’t even a failure mode on a single chain bike.
There’s already plenty of other gearing systems for bikes that only require one chain. Sure, the whole derailleur system can be finicky and easily damaged, but there’s also the 3 speed hubs, where there’s basically a 3 speed gearbox built right into the hub, eliminating the externally exposed gears.
And with the thought of the 3 speed hub (they also make them with more gears than that even), it just seems this dual chain system is a solution to a problem that didn’t exist.
Yeah, adding a chain creates one more failure point, but an internally geared hub adds at least two. One at the hub and another at the shifting mechanism. Additionally internally geared hubs have to be lubricated, adding to the maintenance items, and lubing a hub is certainly more difficult than a 2nd chain.
As I understand it, the bike was designed to make maintenance and repair as easy as possible. I don’t see anyone being able to disassemble & repair a 3 speed, internally geared hub on the side of the road with minimal tools.
Lubing a 3 speed internal hub is actually pretty easy, if you have the right oil injector valve to match the lubrication nipple on the hub.
I’m laughing my butt off just imagining the designers having this exact conversation. I wonder what their final answer or considerations were when they made this choice. Maybe failure mode? If the chain breaks you still have a cart, but if the hub breaks/seized you’d be stuck?
It would be kind of neat if Seth could do some testing to see what happens if one chain breaks, but he seems to be riding a little less dangerously lately