I actuall lived in Beijing for about half a year, right in downtown core... in some hotel name I forget. Anyways, I wasn't a cyclist back then, but I do remember the amount of stuff one guy could be hauling on the back towed. I seem to recall about 10 sofas stacked up, or a bunch of appliances.
There were also flat repair "shops" very other corner, they'd repair it for like 50cents.