CBR Motorcycle Theory A key terms

The total distance a motorcycle travels from the moment the rider recognizes a hazard until the machine comes to a complete halt. It combines reaction distance and braking distance and grows with speed.

The distance covered while the rider is still perceiving a hazard and moving the hand to the brake, before braking actually begins. It depends mainly on speed and rider alertness, not on brake quality.

The distance needed to stop once the brakes are actually applied. It increases with the square of speed, so doubling speed roughly quadruples it, and it lengthens on wet, loose or contaminated surfaces.

The gap kept behind the vehicle ahead so there is time to react and stop. Riders commonly use a two-second rule in dry conditions and extend it in rain, darkness or heavy traffic.

A simple method of checking following distance: pick a fixed roadside point, and ensure at least two seconds pass between the vehicle ahead passing it and your motorcycle reaching it.

The maximum legal speed permitted on a given road, shown by a round sign with a red border and a number. Limits are absolute maxima, not targets, and must be reduced when conditions demand it.

A speed appropriate to actual circumstances such as visibility, surface, traffic and road layout, which may be well below the posted limit. Riding at the limit in poor conditions can still be unsafe and unlawful.

A recommended speed, usually shown on a rectangular or diamond-shaped sign below a warning sign, for a bend, junction or hazard. It is guidance for safe passage rather than an enforceable maximum.

A default rule at unmarked intersections where a rider must give way to traffic approaching from the right. Signage or road markings can override it, so riders must read the junction carefully.

To let other traffic pass before proceeding, shown by an inverted triangle sign or a broken line across the lane. Failing to yield when required is a common cause of junction collisions with motorcycles.

The entitlement to proceed first in a traffic situation, granted by signs, signals, markings or rules. It is never absolute and must not be assumed, since other road users may not respect it.

The rule that traffic already circulating on a roundabout generally has priority, and entering riders must yield. Riders should also watch for vehicles changing lanes or exiting without signalling.

A sign, typically triangular with a red border, that alerts riders to an upcoming hazard such as a bend, slippery surface, crossing or narrowing. It calls for reduced speed and heightened observation.

Painted lines, arrows and symbols on the road surface that regulate or guide traffic, such as lane dividers, stop lines and give-way lines. They remain valid even when no sign is present.

The choice of where within a lane a rider travels, left, centre or right, to maximise visibility, sight lines and safety margins. It changes constantly with traffic, curves, wind and surface hazards.

An area around a vehicle that the driver or rider cannot see in mirrors or by direct vision. Riders should avoid lingering in other vehicles' blind spots and should check their own before changing course.

A brief glance over the shoulder before changing lane, turning or joining traffic, to cover the blind area mirrors miss. It should be quick enough not to jeopardise control of the motorcycle.

Regular use of the motorcycle's mirrors to monitor traffic behind, performed before braking, signalling or changing direction. Mirrors supplement but never replace a direct shoulder check.

The technique of pressing the handlebar on the side you want to turn towards, which initiates a lean at speed. It is how single-track vehicles change direction above walking pace.

The degree to which the motorcycle is tilted into a corner, balancing centrifugal force against gravity. Excess lean on a slippery or uneven surface risks a slide, so entry speed must be set in advance.

The point where the two edges of the road appear to meet ahead. Its movement tells the rider whether a bend is tightening or opening, helping to judge a safe entry speed and line.

The tendency to steer towards whatever the rider stares at, including a hazard. Deliberately looking at the intended path instead of the danger helps avoid riding into it.

The skill of scanning ahead and anticipating developing risks, such as a car door opening, a pedestrian stepping out or gravel on a bend. Early recognition buys the time needed to react.

A planned path of avoidance identified in advance in case a developing hazard blocks the current line. Continuously updating it keeps options open when another road user behaves unpredictably.

A road area with reduced grip, such as wet paint, tram rails, oil, gravel or fallen leaves. Riders should cross it upright, avoid harsh braking or steering, and reduce speed beforehand.

Headgear with a rigid shell and impact-absorbing liner, secured by a fastened chin strap, that reduces head injury in a crash. It must fit correctly and be replaced after a significant impact.

The transparent face shield on a helmet that protects the eyes and face from wind, debris and weather. It must be kept clean and unscratched, since glare and smearing impair vision.

Purpose-made riding gear such as abrasion-resistant jacket and trousers, gloves and reinforced boots. It shields skin from road rash and impact, and bright colours or reflective strips improve being seen.

How easily a rider is noticed by other road users, improved by headlights, bright or reflective clothing and avoiding another vehicle's blind spot. Being seen is a core defensive riding aim.

The depth of the grooves on a tyre, which clears water and limits aquaplaning risk. Worn or unevenly worn tyres reduce grip and should be checked regularly against the legal minimum.

The inflation level of a tyre, which affects grip, stability, wear and fuel use. It should be checked cold against the manufacturer's figures, since incorrect pressure degrades handling and braking.

A quick inspection before setting off covering tyres, brakes, lights, controls, chain and fluid levels. It catches defects that would otherwise become emergencies at speed.

The motorcycle's front and rear brakes, which should be tested for response and lever or pedal feel before riding. Front brake provides most stopping power, while the rear adds stability.

The correct slack in the drive chain, set per the manufacturer's specification. A chain too tight or too loose can damage components or derail, so it belongs in routine maintenance checks.

Immediate basic care given to an injured person before professional help arrives, such as controlling bleeding, maintaining breathing and keeping them warm. It should never delay calling emergency services.

Contacting the emergency number to request ambulance and police help after a crash. The caller should give a precise location, number of casualties and hazards, and follow the operator's instructions.

Making the crash site as safe as possible before helping, for example by warning traffic, switching off engines and not moving casualties unless there is immediate danger such as fire.

Substances that impair judgement, reaction time and balance, making riding unlawful and dangerous. Even small amounts or some medicines can seriously reduce the ability to control a motorcycle.