A bobber is a custom built motorcycle, typically bare bones and devoid of most non-essential embellishments. Some motorcycle kits are quite complete, allowing the builder to assemble an entire bike with few modifications and purchases. Other bobber motorcycle kits are known simply as rolling chassis, or a frame on wheels. These require a far more experienced custom bike builder who knows what they are doing and, just as important, where to get everything he or she will need.
One of the most popular budget concious bobber kits produced are the kikker hardknock from the u.s.a. in a traditional "old school" style with a short wheelbase allowing you to take on corners easier. It is comprised of numerous polished billet aluminum components and (there's no plastic or fiber glass parts) a good quality kit with forward controls, TIG welded 4130 chrome-moly frame, a lowered sunken solo seat which allows you to be positioned inside the chassis adding to the unique sensation of riding low to the ground. On the high end side, there is no limit other than what you are willing to spend on the kit, custom parts, accessories, upgrades, chroming, powder coating, a professional paint job ... you name it.
Bobbers are related to choppers in that they both take a minimalistic approach to custom bike building. This includes the characteristic rigid frame and shortened "bobbed" rear fender. The main difference is that bobbers are typically built around unstretch frames and stock fork rake, while a chopper frame is often stretch out and welded into shape with enlongated forks. Bobber kits are good for traffic city streets and a good place to start for hobbyists new to bike building before moving up to a totally custom chopper.