Zwei plus Zwei are a bit obsessed with safety testing! They’ve fatigue-tested all their frames and forks. The result is a couple of light yet very durable aluminium tandem frames... Both frames have the DTD (Don’t Turn the Driver) system - this puts the handlebars on a separate post from the pilot’s saddle, so they can be quickly and independently adjusted. Also, there is no way that the stoker can accidentally turn the pilot’s saddle - a common problem with more normal tandems. Zwei plus Zwei make two tandems - the City models have a very low easy-access frame, whereas the Sport models are better for touring or longer distances. | 
