There’s an old cyclist’s mantra that wisely suggests you give your bike a quick once over before heading out. It’s something that an every rider should do, even the pros doing the Tour de France will quickly check their bike, even if it’s been done beforehand by some highly qualified mechanic.
It’s catchily known as ABC … Air | Brakes | Chain. Give your tyres a pinch front and back and make sure they are good and firm; try out your brakes front and back wheeling the bike back forth applying each brake at a time making sure the bike stops. Additionally have a quick look at the brake pads, are they worn and do they full strike the wheel rim (and not the tyre or only part of the rim). Finally, the chain, check that it is slightly oily, slightly loose and mainly not covered in gunk (technical term).
So that's what you should do - but why?
A - Air, under-inflated tyres will puncture more often for a couple of reasons. A soft tyre will ‘grip’ those shards of glass or flint as they gradually penetrate the tyre as you roll along. Less understood, is that an under inflated tyre is prone to ‘snake bite’ punctures, named from the pair of parallel slits in the inner tube that look as if a cobra has attacked it. Snakes bite when you hit a pothole as the outer tyre pinches the inner tube on the wheel rim and whamo, you’re left with a very difficult roadside repair.
B – Brakes, the why should be bleedingly obvious on this one, there are times when you need to stop! Please, please if your brakes are dodgy and you can't fix them, get them sorted by a bike shop/competent mechanic before you inadvertently … well, hurt yourself. There are some good shops listed here.
C – Chain and the why here often overlooked. A dirty grimy chain is less efficient, making it harder to pedal – very tiresome. The dirt and gunk make a very efficient grinding paste which will quickly knacker the chain, gears and the big chainring. At the other end of the scale, a dry rusty chain will squeak, moan, skip gears and generally misbehave. You’ve guessed it, a dry chain is really inefficient, which makes pedalling much much harder, not so important on the quick trip to the shops, but again unnecessarily tiring on a 20-mile ride!
Lastly, gears, chains and chainrings are expensive to replace, so it’s worth spending a little time looking after them - what you're looking for is a clean, lightly oiled chain with the links moving freely - it will save you money and effort.
And that's it - in essence, the more you look after your bike, the more it will look after you.