Spotting abnormal tire wear and correcting the cause can significantly extend tire life. Normally, tires will wear evenly across their surface until they reach the wear bars, which are 2/32nds of an inch above the bottom of the tread. When the tires are worn to the wear bars, they should be replaced.
One shot (1.5 ounces) of espresso has about two tablespoons of coffee (about 1/4 ounces). For best flavor, one shot of espresso, or two tablespoons of coffee, should be used to make 6 ounce of coffee drink. Likewise, a 12 ounce coffee drink will taste best with two shots of espresso.
Depending on your dose and basket size, shoot for about 2 ounces of espresso out, enough to fill a large shot glass. If you're weighing your shots, a 30-gram yield is a safe place to start. Note: The density of espresso can be a tricky thing, as the gasses trapped in the crema can make for fluffy, heady shots that only weigh 30 grams, or thin and silky shots that weigh 60. With many espresso blends, you should have a decent cap of crema - say, a 1/2 inch or so - and a total mass of about 30-40 grams for a 2-ounce shot. But some coffees will skew one way or the other, leading to less dense crema-bombs or denser, juicier single origin marvels.