Between the extremes of bicycles with classical front-wheel steering and those with strictly rear-wheel steering is a class of bikes with a pivot point somewhere between the two referred to as center-steering, similar to articulated steering. An early implementation of the concept was the Phantom bicycle in the early 1870s promoted as a safer alternative to the penny-farthing.[51] This design allows for simple front-wheel drive and current implementations appear to be quite stable, even ridable no-hands, as many photographs illustrate.[52][53] These designs, such as the Python Lowracer, usually have very lax head angles (40° to 65°) and positive or even negative trail. The builder of a bike with negative trail states that steering the bike from straight ahead forces the seat (and thus the rider) to rise slightly and this offsets the destabilizing effect of the negative trail.[54] Articulated steering is a system by which a four-wheel drive vehicle is split into front and rear halves which are connected by a vertical hinge. The front and rear halves are connected with one or more hydraulic cylinders that change the angle between the halves, including the front and rear axles and wheels, thus steering the vehicle. This system does not use steering arms, king pins, tie rods, etc. as does four-wheel steering. If the vertical hinge is placed equidistant between the two axles, it also eliminates the need for a central differential, as both front and rear axles will follow the same path, and thus rotate at the same speed. Long road trains, articulated buses, and internal transport trolley trains use articulated steering to achieve smaller turning

ircles, comparable to those of shorter conventional vehicles. Articulated haulers have very good off-road performance. Penny-farthing, high wheel, high wheeler, and ordinary are all terms used to describe a type of bicycle with a large front wheel and a much smaller rear wheel that was popular after the boneshaker, until the development of the safety bicycle, in the 1880s.[1] They were the first machines to be called "bicycles".[2] Although they are now most commonly known as "penny-farthings", this term was probably not used until they were nearly outdated; the first recorded print reference is 1891 in Bicycling News.[3] It comes from the British penny and farthing coins, one much larger than the other, so that the side view resembles a penny leading a farthing.[4] For most of their reign, they were simply known as "bicycles". In the late 1890s, the retronym "ordinary" began to be used, to distinguish them from the emerging safety bicycles,[5] and this term or Hi-wheel (and variants) is preferred by many modern enthusiasts.[6][7] About 1870, James Starley, described as the father of the bicycle industry, and others began producing bicycles based on the French boneshaker but with front wheels of increasing size,[4] because larger front wheels, up to 1.5 m (60 in) in diameter, enabled higher speeds on bicycles limited to direct drive.[1][4][8][9][10] In 1878, Albert Pope began manufacturing the Columbia bicycle outside of Boston, starting their two-decade heyday in America.[4] Although the trend was short-lived, the penny-farthing became a symbol of the late Victorian era. Its popularity also coincided with the birth of cycling as a sport.