Mechanical Knowledge Flashcards
6 cards from real DVSA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Mechanical Knowledge flashcards as text
What do motorcycle disc brakes use to translate lever or pedal pressure into stopping force?
Answer: Hydraulic pressure pushing caliper pistons to clamp brake pads against the rotating disc
Disc brakes use hydraulic fluid to transmit lever pressure through hoses to caliper pistons which press brake pads against the disc rotor, generating friction to slow or stop the wheel.
Why is it important to replace motorcycle brake fluid periodically?
Answer: Brake fluid is hygroscopic (absorbs moisture), lowering its boiling point and increasing the risk of brake fade under repeated heavy use
Moisture absorbed from the atmosphere lowers the fluid's boiling point; under sustained braking the fluid can boil, creating gas bubbles that are compressible and cause a sudden complete loss of braking pressure.
What is the function of the regulator/rectifier on a motorcycle's electrical system?
Answer: It converts AC electricity from the alternator to DC and regulates voltage to prevent overcharging the battery
The alternator produces AC current that varies with engine rpm; the rectifier converts it to DC and the regulator prevents excess voltage reaching the battery, protecting both the battery and electrical components.
What does 'stand on the pegs' technique achieve when riding over a rough or uneven surface?
Answer: Uses the rider's legs as additional suspension, allowing the motorcycle to follow the surface while the rider's body remains stable
Standing on the pegs with flexed knees allows the legs to act as an additional suspension system; the bike's wheels can move over rough ground while the rider's body remains relatively isolated from the impacts.
What is counter-steering and when is it used on a motorcycle?
Answer: Briefly pressing forward on the handlebar on the side of the intended turn at speeds above approximately 25 mph — this initiates lean and thus the turn
Counter-steering (pushing on the bar in the direction of turn) is used instinctively by experienced riders above low speeds; it is the primary mechanism for initiating lean-induced turning on two-wheeled vehicles.
What is the consequence of riding a motorcycle with a worn rear sprocket?
Answer: Increased chain wear, higher risk of chain jump or snap under power, and imprecise power delivery
A worn sprocket has hooked teeth that accelerate chain wear, may cause the chain to jump under load, and reduces power transmission efficiency; both sprockets and chain should be replaced together.