Bicycle and motorcycle geometryBicycle and motorcycle geometry is the collection of key measurements (lengths and angles) that define a particular bike configuration. Primary among these are wheelbase, steering axis angle, fork offset, and trail. These parameters have a major influence on how a bike handles. WheelbaseThe wheelbase is the horizontal distance between the centers (or the ground contact points) of the front and rear wheels.Directional stabilityDirectional stability is the tendency of a vehicle or moving body to keep its orientation aligned with its direction of movement. When a car or an airplane gets turned a little relative to its direction of motion, it might correct itself, over-correct itself, or it might start to spin out of control. If it tends to correct itself, we say it is directionally stable, while if it tends to spin out, we say it is directionally unstable.
Ball jointIn an automobile, ball joints are spherical bearings that connect the control arms to the steering knuckles, and are used on virtually every automobile made. They bionically resemble the ball-and-socket joints found in most tetrapod animals. A ball joint consists of a bearing stud and socket enclosed in a casing; all these parts are made of steel. The bearing stud is tapered and threaded, and fits into a tapered hole in the steering knuckle.Kingpin (automotive part)The kingpin (also king-pin, king pin and k pin) is the main in the steering mechanism of a car or other vehicle. The term is also used to refer to part of a fifth wheel coupling apparatus for a semi and its trailer or other load. HistoryOriginally, with the 'turntable' steering of horse-drawn wagons, this was a single pin on which the moveable axle was pivoted beneath the wagon's frame.
Contact patchThe contact patch is the portion of a vehicle's tire that is in actual contact with the road surface. It is commonly used in the discussion of pneumatic (i.e. pressurized) tires, where the term is used strictly to describe the portion of the tire's tread that touches the road surface. The term “footprint” is used almost synonymously. Solid wheels also exhibit a contact patch which is generally smaller than the pneumatic “footprint”.
WheelA wheel is a rotating component (typically circular in shape) intended to turn on an axlebearing. The wheel is one of the key components of the wheel and axle, which is one of the six simple machines. Wheels, in conjunction with axles, allow heavy objects to be moved easily, facilitating transportation, supporting loads, and performing work in machines. Wheels are also used for other purposes, such as a ship's wheel, steering wheel, potter's wheel, and flywheel.
Shopping cartA shopping cart (North American English), trolley (British English, Australian English), also known by a variety of other names, is a wheeled cart supplied by a shop or store, especially supermarkets, for use by customers inside the premises for transport of merchandise as they move around the premises, while shopping, prior to heading to the checkout counter, cashiers or tills.
BicycleA bicycle, also called a pedal cycle, bike, push-bike or cycle, is a human-powered or motor-assisted, pedal-driven, single-track vehicle, with two wheels attached to a frame, one behind the other. A bicycle rider is called a cyclist or bicyclist. The bicycle was invented in Europe in the 19th century. By the early 21st century, there were more than 1 billion bicycles. Bicycles are the principal means of transport in many regions.
VehicleMobile equipment that transports people, animals or cargoCars, motorcycles, and a bus on display in Thame, England in 2009A train passing a group of boats near the River Dart, England in 2016Bicycles, electric bicycles, and scooters in Yangzhou, China in 2008A Space Shuttle and a 747 above California, United States in 1977A vehicle (from Latin vehiculum) is a machine designed for self-propulsion, usually to transport people, cargo, or both.
MotorcycleA motorcycle (motorbike, bike, or, if three-wheeled, a trike) is a two or three-wheeled motor vehiclesteered by a handlebar from a saddle-style seat. Motorcycle designs vary greatly to suit a range of different purposes: long-distance travel, commuting, cruising, sport (including racing), and off-road riding. Motorcycling is riding a motorcycle and being involved in other related social activities such as joining a motorcycle club and attending motorcycle rallies.Dual ball joint suspensionA dual ball joint suspension uses a pair of simple links to replace a wishbone in a MacPherson or SLA suspension. The outer end of each arm terminates in a ball joint, hence the name. General descriptionThe two links, the spindle, and the body, form a four-bar link.
CasterA caster (or castor) is an undriven wheel that is designed to be attached to the bottom of a larger object (the "vehicle") to enable that object to be moved. Casters are used in numerous applications, including shopping carts, office chairs, toy wagons, hospital beds, and material handling equipment. High capacity, heavy duty casters are used in many industrial applications, such as platform trucks, carts, assemblies, and tow lines in plants.
CarMotorised passenger road vehicleA car, or an automobile, is a motor vehicle with wheels. Most definitions of cars state that they run primarily on roads, seat 1–8 people, have four wheels, and mainly transport people rather than cargo. There are over 1.6 billion cars in use worldwide as of 2025.
lateralRelated word or term.*As an Amazon Associate I earn from qualifying purchases.