Cycles of all sorts

First and foremost a cyclist needs a well maintained and functional machine. The bicycle is one of the few consumer durables still intended to be maintainable by the owner: most cycle maintenance is simple and requires only basic tools. At the very least the rider should regularly check safety-critical components:

• Brakes: the front brake should be capable of locking the front wheel so that if the bike is pushed forwards, the rear wheel lifts; the rear brake should be capable of skidding the rear wheel.
• Headset: with the front brake firmly on, rock the bike forwards and backwards. If you feel a clunk as the bike moves, and the handlebars move around, then the headset probably needs adjusting or replacing.
• Tires: inspect your tires regularly for cuts and wear. Worn tires can blow out, with perilous consequences. They also puncture more readily. Check that your tires are pumped up enough. Pinch the tire between thumb and forefinger: It should feel hard. Mountain bike tires typically run at about 45psi, road bike tires at anything up to 120psi. Do not use garage forecourt airlines to inflate bike tires, use a proper pump preferably with a pressure gauge. Over-inflated tires can lift off the rim and burst. Under-inflated tires compromise control and can result in pinch flats, also known as snakebite punctures for their characteristic double holes.
• Wheels: In turn, lift each end of the bike and spin the wheel. It should spin freely and the rim should remain roughly the same distance from the brake blocks. A wheel which is badly out of true may indicate a broken spoke - this should be fixed as soon as possible or else more spokes (or the whole wheel) will probably soon fail. Try to move the rim from side to side. If it moves or you feel a clunk, then the bearings may be worn and should be checked. If the wheel feels gritty as it spins, or rumbles, the bearings are probably damaged.
• Handlebars: stand in front of the bike, facing towards it; hold the front wheel between your legs; grab the handlebars and try to turn. If the bars twist on the stem, tighten them.
• General: if you have mudguards (fenders), a rack, a chain guard or any other equipment attached to your bike, give it a good rattle from time to time and check that it is still securely fixed. Loose mudguards, for example, can go in your wheel and bring you down.