While I was India I was fascinated that most of the bicycles on the street were made in India and based on an old design. They are used for transportation and transporting. I saw so many of them hauling all manner of loads from vegetables to milk. They are all single speed. They have a number of unique features. One is the straight pull brakes that grab on the inside of the rim. They are very simple and rely on simple rods and stampings instead of cables and castings. I saw one guy hauling 3 cooking gas bottles up a mountain road. They hold 17kg of gas, so I estimate 3 full bottles to be 150 lbs. No wonder he is walking. The other interesting bike was one set up with a grinding wheel on the top tube. He went from shop to shop sharpening knives and scissors. I made a short video:
Ride Safe, Joe