Furry's fat and long bikes

How do the funny cranks and rear hub take the very low gears and EPIC TORQUE that they're probably not designed for?

Not sure if it was resolved as a manufacturing issue but

Awesome legs.....

Its the cog sitting around the axle in this pic. It is a big chunk of metal. after less than 50 miles, I'm hoping its a manufacturing fault. Although I reckon a SS MTB crank, with a 31 tooth chainring would do the job, having ridden the bike with various loads.