Chicago-based nonprofit World Bicycle Relief (WBR) doesn't distribute just any type of bicycle – it distributes bicycles meant to navigate the unimproved roads and rough terrain of developing nations, empowering populations to access healthcare, education and economic opportunities that would…
Chicago-based nonprofit World Bicycle Relief (WBR) doesn't distribute just any type of bicycle ??? it distributes bicycles meant to navigate the unimproved roads and rough terrain of developing nations, empowering populations to access healthcare, education and economic opportunities that would???
Instead of equipping the bike with a bunch of cogs, cables and added components, it's split the powertrain out into two separate drives: a high chainring connected to a rear cog via a dedicated chain and a low chainring chained to a second rear cog on the same hub. All hardware is located on the right side of the bike, and the rider simply backpedals half a revolution to activate the switchable freewheel from high to low and vice versa.
Neat idea! The shifting cog might be a unique part that’s hard to source but maybe they found a way to macguyver it from common parts, or worst case scenario one could slap a standard cog and some spacers on there in a pinch.
As for the 2-chainz design, I think it's fairly brilliant, as a way to avoid a delicate derailleur, which MTBers will know is vulnerable on terrain due to being low-slung. This sort of thinking also highlights how engineering and design make tradeoffs, since the weight penalty of an extra chain is not important when the ultimate objective is a rugged, durable bicycle.
We do? They have internally geared hubs of up to 12 speeds now (but they are very, very, very expensive - check out Rolhoff, they're pretty much the gold standard of internally geared hubs, if you want something more affordable Shimano Alfine is much more affordable and does 8x I believe)
I rode a two speed kickback bicycle similar (operationally) to this for about a decade. It was the lowest maintenance bike I've ever owned, but the gearing was inside the rear hub and it only had a single chain. I can't imagine that the mechanism being outside improves that.