Bike tires, unlike car tires, lose their pressure on a daily basis, so its necessary to check their pressure daily and reinflate when necessary.A few days ago, I was driving happily along the highway, heading home from a run to a bookstore. A passing motorist honked at me and then pointed toward my car as if there were something wrong with it. I nodded and waved and slowed down, and they passed me. However, my car was behaving as it always had... there was no "pull" or rough riding to indicate that I had a flat tire. So, since I was only ten minutes from home I just kept on driving - albeit more slowly.My mind being what it is, as soon as I pulled into the driveway I forgot all about the reason why I had been driving slowly for the last ten minutes, and just walked into the house.The next day, I got into the car and had driven out of my apartment parking lot toward the access road for the main drag, before remembering that there was supposedly something wrong with one of the tires. So I returned to the parking lot, got out, and looked at my tires. The rear left was as flat as a pancake.I couldn't have driven home with it like that - it surely would have effected the handling of the car. So yesterday the tire must simply have been low, and continued going flat over night. My dad, who had witnessed my return, asked me if I didn't check the tires before I got behind the wheel every single time, and I confessed that I didn't. I've been driving for years and years and never had a flat tire before, so why bother?But I learned my lesson from that little incident, and now I take a few seconds and check the tires before leaving.And that little story brings me to the point of this essay, which is that before you get on your bike - there are various things you should check to make sure you'll have a safe ride. Indeed, in spite of my carelessness with my car tires, I always had and always will check my bicycle tire pressure before setting off on a ride. The more so because I have had a couple of flat tires with that bike over the five years that I've owned it. Tire pressure is important for cars, because if a tire blows while the car is traveling at high speed that's a heavy piece of machinery that will go out of control. But it's just as important for bicyclists, because since you have to use your own power to muscle along the bike, flat tires will effect your ride from the very beginning. And if you're far away from home when the tire gives up the ghost, you could find yourself with a long walk home.There's no difficulty in knowing how many pounds of pressure need to be put into your bike tires - the manufacturer puts those specifications on the side of each tire. Get yourself a tire gauge and always use it when you inflate your tires. However, although you won't want to exceed the pounds per square inch that they recommend, there are reasons why you'd sometimes want to use less. With a tire inflated to the correct pressure, your ride will be as smooth as the quality of your frame will allow it. If your tires aren't inflated enough it increases the chance of getting a flat tire, but more importantly makes it harder to pedal. Too high of pressure will strain the tire itself, not to mention making the ride too bumpy to be comfortable.Bike tires lose their pressure on a regular basis, so before starting out on your ride, always squeeze both front and back tires to ensure that they are hard. Mountain bikers do like their tires "mushier" than other bikers, and if that applies to you just become familiar with what the appropriate tire pressure for you looks and feels like.