So, lets say your bike needs to be pumped up. The first step would be to remove the valve cap, which we've already done. Most pumps are equipped today with two apertures, the larger one is for the schrader valve, the smaller is for the presta valve. We'll start by showing you how to use the schrader valve. The first step would be to push this on, you usually have to cover all the threads, and then clamp it. Some pump chucks work in reverse, you have to flip the lever up to clamp, some down to clamp. We look at the gauge, it's reading fifty pounds, you should look carefully on the sidewall on your tire, its pressure rating will be listed there. This particular tire is sixty to eighty pounds, so we're going to pump it up to a minimum of sixty, if you're a heavier rider you want to go right up to the eighty pounds, if the tire is old and dry rotted you may want to stick to the lower pressure rating, and then get to the shop and replace it. When done, release the lever, often you'll hear some air escaping, that's only air coming out of the pump itself, find your valve cap, and replace it. On these kinds of valves, the valve cap is there to keep dirt out, not to hold pressure in. On a presta valve, it's an added step, after you remove the cap, you do have to loosen this, it does not come off completely, if it does it's broken. Second step here is to touch it once, make sure that it's not stuck, when they sit for a while they stick. Push on the chuck, carefully as not to bend the mechanism, clamp it, check your pressure, usually after a stroke or two on a high pressure tire. This tire is right up to pressure, probably pumped in the last few days. This tire is rated for about a hundred and twenty, and there we go. Now, releasing the chuck on a presta valve, you want to flip the lever to its release mode and gently wiggle it straight off. Once again we heard a bunch of air come out, it's from the hose, if you pulled it straight off you didn't lose any out of the tire. Very important, you've gotta close the valve and you're done.
