Each skateboard wheel is mounted on its axle via two bearings. With few exceptions, the bearings are the industrial standard "608" size, with a bore of 8 mm (or 10mm depending on the axle), an outer diameter of 22 mm, and a width of 7 mm. These are usually made of steel, though silicon nitride, a high-tech ceramic, is sometimes used. Many skateboard bearings are graded according to the ABEC scale. The scale starts with ABEC1 as the lowest, followed by 3, 5, 7, and 9. It is a common misconception that the higher ABECs are better for skateboarding, as the ABEC rating only measures tolerances, which do not necessarily apply to skateboards. Bearing performance is determined by how well maintained the bearings are. Maintenance on bearings includes periodically cleaning and lubricating them . Bearings that are kept unmaintained have their performance greatly lowered and will soon need to be replaced. Bearing cleaning kits are commonly available on the market. The ABEC rating does not determine the speed or durability of a skateboard bearing. In particular, the ABEC rating says nothing about how well a bearing handles axial (side-to-side) loads, which are severe in most skateboard applications. Many companies do not show the ABEC rating, such as Bones Bearings, which makes bearings specifically for skateboarding, often marketed as "Skate Rated". Each bearing usually contains 7 steel or ceramic bearing balls, although other configurations are used as well.
So the proper foot placement for the ollie is with the ball of your back foot horizontal on the tail of your skateboard. And your front foot centered on your board right behind the front trucks. You may find that moving your feet around in different positions are more comfortable. This is fine, everybody can learn how to skateboard their own way.
Slide your front foot as soon as you start jumping. Use the same movement you have been practicing to slide your foot towards the top end of the board, just as you jump off it and kick the back down. The front of your board should lift up as you slide your foot along it, with your foot hitting the top of the board at the highest point of your jump.
Ohderii Skate Skateboards are made of a High-quality Plastic deck which will not easily break even when pressed over by a car. It comes with 3.125″ all aluminum alloy trucks, 59mm 78A super smooth PU wheels and ABEC-7 stainless steel bearings. It is ready to use and you can easily store it in your backpack. It has an average rating of 4.5 on Amazon.