An annual bike service generally includes an oil and oil filter change. The air filter also needs to be inspected and cleaned or replaced depending on its condition. Apart from that, annual service includes inspection of all electricals such as lights and horn, throttle inspection, clutch inspection, checking the condition of chain and sprockets, inspection of brake pads/callipers/discs, checking suspension and tyres, inspection of all critical bearings, and checking the condition of the battery. All fluid levels such as coolant and brake fluid need to be topped up. And depending on the condition, the spark plug/s also might need to be replaced.