Vehicle knowledge, controls, and maintenance
Domain 3 covers the machine: what the controls do, what to check before every ride, the wear limits, and the symptoms that mean stop riding. Expect questions on chain slack, tyre tread and pressure, brake checks, and the consequences of neglect.
Controls
Right hand: throttle and front brake. Right foot: rear brake. Left hand: clutch. Left foot: gear lever - first gear down, then neutral and up through the box. Know the engine cut-off switch and the fuel tap or reserve position before you need them.
The pre-ride check
- Tyres: pressure measured cold, set for solo or two-up as stated in the manual. Tread depth minimum 1.0 mm for a motorcycle in Denmark - and check for cuts, bulges and embedded objects.
- Chain: correct slack, typically 25-35 mm on a 125, lubricated, with no tight spots. Hooked or sharpened sprocket teeth mean replacement.
- Brakes: firm lever and pedal, no sponginess, fluid above the minimum mark, pads well clear of the backing plate.
- Lights, indicators, horn and mirrors.
- Oil level, leaks under the bike, coolant if liquid-cooled.
Wear and fault symptoms
A pulsing front lever usually means a warped disc. A wobble can mean a badly seated tyre or worn bearings. A dragging brake makes the bike pull to one side and blues the disc. Chain noise and vibration often mean a dry or over-tight chain - over-tightening damages the gearbox output bearing.
Worked example
The rear tyre reads 1.5 bar, but the manual specifies 2.3 bar for two-up riding. The rider last checked it on a hot day straight after a ride. He should not top it up "until it feels right": pressure must be set cold, to the manual figure for the actual load. Low pressure makes the tyre flex and overheat, reduces grip and slows the steering. Check and correct cold before setting off.
Traps
Measuring pressure when the tyre is hot and setting it to the cold figure, so it ends up too low. Adjusting the chain by feel and leaving it bar-tight. Treating the 1.0 mm tread limit as a suggestion. Ignoring a spongy lever because "it still stops".