Here is another tip, to go with the pre-ride check up. It's a little wordy, but I think it is very important. No tools required. The last thing to do before getting on the bike...
The Drop Test
Simply lift your bike about 5cm (2 inches) off the ground and drop it on its tires. You should keep at least one hand in light contact with the bike when it lands. Try to have both wheels hit at the same time. Listen carefully. If there are any loose parts on the bike, you will either hear the rattling or even feel the excess vibration when the bike hits the ground. There is a distinct difference between the thud of inflated rubber tires, and the pinging sound of a loose part. If you do this before every ride, you will easily notice when something doesn't sound right. Before you start your ride, you must identify and correct the problem. To get the feel for this, do a drop test…then, open your quick release (or loosen your front wheel nuts) and do it again. You will notice a very nasty sounding rattle that will tell you something is wrong. (Now close the QR or tighten your wheel nuts, before you forget.) The vibration of a loose part is transmitted and amplified through the entire bike when you are not on it. During a ride, the compression of your weight on the bike will suppress most of the vibration and you might not realize that your wheel or some other important/expensive part is about to fall off.
If you have presta valves with those little locknuts, you should be able to hear them rattle if they are loose, but it won’t be as loud and obvious as having a loose quick release. Try it. Listen carefully. Your bike is screaming for attention.
Here are a few other things I hear or feel when I do a drop test…loose headset, loose hubs, broken spoke, sore toe, loose brake shoe, exploding tube, loose reflectors, lights and computers not completely seated in their brackets, loose bolts on racks and other accessories, broken parts, even cracks in the frame.
by: Bill Goldston, Framework Fitness and Bikes, Sydney