The wheels of a skateboard are usually made of polyurethane, and come in many different sizes and shapes to suit different types of skating. Larger diameters (55–85 mm) roll faster, and move more easily over cracks in pavement and are better for transition skateboarding. Smaller diameters (48–54 mm) keep the board closer to the ground, require less force to accelerate and produce a lower center of gravity which allows for a better response time, but also make for a slower top speed and are better for street skateboarding. Wheels also are available in a variety of hardnesses usually measured on the Shore durometer "A" scale. Again like car tires, wheels range from the very soft (about Shore A 75) to the very hard (about Shore A 101). As the A scale stops at 100, any wheels labeled 101A or higher are harder, but do not use the appropriate durometer scale. Some wheel manufacturers now use the "B" or "D" scales, which have a larger and more accurate range of hardness. Modern street skaters prefer medium-sized wheels (usually 51–54 mm), as small wheels with lighter trucks can make tricks like kickflips and other flip tricks easier by keeping the center of gravity of the skateboard closer to the deck, thus making the deck easier to spin. Street wheels are harder (A 100/A 101). Vertical ramp or "vert" skating requires larger wheels (usually 55–65 mm), as it involves higher speeds. Vert wheels are also usually slightly softer (A 98/ A 99), allowing them to maintain high speed on ramps without sliding. Slalom skating requires even larger wheels (60–75 mm) to sustain the highest speeds possible. They also need to be soft and have better grip to make the tight and frequent turns in slalom racing. Even larger wheels are used in longboarding and downhill skateboarding. Sizes range from 65 mm to 100 mm. These extreme sizes of wheels almost always have cores of hard plastic that can be made thinner and lighter than a solid polyurethane wheel. They are often used by skateboard videographers as well, as the large soft wheels allow for smooth and easy movement over any terrain.
This is how I learned how to ollie. Place your skateboard next to a curb, right up against it. This will help keep your board from rolling. Next, do everything that I just described, but don’t worry about what your board does. Just do it, and land up on top of the curb, on the sidewalk. Don’t stress about whether the skateboard will be there, or if you will get hurt – just go through the motions of ollying up the curb. If you do it right, the skateboard will be there. If you do it wrong, you’ll probably just land on your feet on the sidewalk. Here’s the key – just do it and expect it to work. Your body understands what you are trying to do, and the less you stress, the more it can kick in and fill in the blanks.
Position your front foot near the middle and your back foot on the tail – The best position is for the ball of your back foot to be slightly hanging off, and the front foot more towards the middle. The position of the front foot can change, however, depending on how much air you want to get: if you’re planning on doing a monster jump, move the front foot closer to the back; if you’re just hopping a little bit, move it closer to the front of the board itself. Beware though, the closer you move it towards the back foot, the harder the trick is to perform.
In 1982, while competing in the Rusty Harris contest in Whittier, California, Rodney Mullen debuted an ollie on flat ground, which he had adapted from Gelfand's vertical version by combining the motions of some of his existing tricks. Mullen used a "see-saw" motion, striking the tail of the board on the ground to lift the nose, and using the front foot to level the board in mid-air.[2] While Mullen was not initially impressed with his flat ground ollie, and did not formally name it, he realized it opened up a second, elevated plane on which to perform tricks.[citation needed]
When you’re searching for one of the best skateboard decks on the market, it’s important to not go overboard. You don’t need one that is made from the rarest wood or has the most unique design. The best boards may be the ones that balance cost, design and quality. Afterall, with healthy use, you’ll eventually have to replace your deck anyway. You want the one that will give you the most functionality and happiness while you use it.
The official record for the highest flat-ground ollie is 45′ (114.3cm) by Aldrin Garcia during the “Maloof High Ollie Challenge,” held on the 15th of February, 2011. You can watch the movie here. However, a groundbreaking moment in the lore of the ollie will always belong to Danny Wainwright’s ex record of 44.5′ (113.03cm, ELEMENT-HIGHEST OLLIE CONTEST Feb.6th,2000.) Reese Forbes, a competitor of Danny’s in this contest, was also well-known as a master of the ollie.

To get higher ollies, I would suggesting resting your back foot on the very end of the tail and the front foot in the middle of the deck to allow for more slide. Popping as hard as you can and catching your board in the groove of the nose with you ankle practically resting in the groove will level the board out in the air. after this initial movement slide you feet back to the bolts on the tail and nose to ensure a clean landing.