[Ignition]

Bobber:

The bobber was the earliest simple and stripped down custom motorcycle hand-built by individuals with mechanical skills, and was often part of the early biker clubs scene before there were any such things as choppers.[2] This style of custom motorcycle, which took shape in the 1940s and 50s,[3] is generally thought to have been started by returning WWII American servicemen working on ex-military motorcycles, and inspired by lighter European motorcycles they had seen and ridden.[4] When bobbers were first created, the intent was not to create a new type of motorcycle or sub-genre, the idea was to keep motorcycles on the road for as cheaply as possible.

Chopper:

The principal difference between a bobber and chopper is that bobbers are typically built around unmodified frames. Chopper frames are often cut and welded into shape. Bobbers also often lack most of the chopper's aesthetic characteristics such as chromed parts and elongated forks. Thus, bobbers are fairly easy to create from stock motorcycles and are generally hand built.
The term chopper started to be used from the late 1960s onwards, for motorcycles whose frames had been customized to have a greater angle at which the front suspension protruded, with smaller fuel tanks and tall handlebars called ape hangers.[2] For many owners, the difference between bobbers and choppers doesn't come down to what's on the motorcycle but what isn't on it and whether it has a short front end or a long front end, stretched suspension defining it as a chopper.[10][11]
While customized motorcycles can be expensive, bobber builders tend to adopt an economical approach involving old, second hand, recycled parts and hand machined items redolent of the period before the mass-market motorcycle accessory industry had developed.

Cafe Racer:

Café racer (/ˈkæff reɪsər/ kaff racer) is a term which arose among British motorcycle enthusiasts of the early 1960s, particularly the "Rocker" or ton-up boy subculture.[1][2][3][4] or (Ca-phay racer),[5][6] The term refers to a style of motorcycle that was and is used for fast rides from one "transport café"[7][8] or coffee bar to another.[9] Motorcycles of this type were also common in Italy, France, and other European countries.[10]
The café racer is a motorcycle that has been modified for speed and handling rather than comfort. The bodywork and control layout of a café racer typically mimicked the style of a contemporary Grand Prix roadracer, featuring an elongated fuel tank, often with dents to allow the rider's knees to grip the tank, low slung racing handlebars, and a single, rearwardly mounted, humped seat.
One signature trait were low, narrow handlebars that allowed the rider to "tuck in" to reduce wind resistance and offered better control when in that posture. These are referred to as "clip-ons" (two-piece bars that bolt directly to each fork tube), or "clubmans" or "ace bars" (one piece bars that attach to the stock mounting location but drop down and forward). The ergonomics resulting from low bars and the rearward seat often required "rearsets", or rear-set footrests and foot controls, again typical of racing motorcycles of the era. Distinctive half or full race-style fairings were sometimes mounted to the forks or frame.
The bikes had a raw, utilitarian and stripped-down appearance while the engines were tuned for maximum speed. These motorcycles were lean, light and handled road surfaces well. The most defining machine of the heyday of the type was "The Triton", which had a homemade Norton Featherbed frame and Triumph Bonneville engine. It used the most common and fastest racing engine combined with the best handling frame of its day, the Featherbed frame by Norton Motorcycles. Those with less money could opt for a "Tribsa" - the Triumph engine in a BSA frame. Other combinations such as the "Norvin" (a Vincent V-Twin engine in a Featherbed frame) and racing frames by Rickman or Seeley were also adopted for road use.[10]