The volcanic creation of the Canadian Shield took place during the Earthâs earliest geologic era, the Precambrian, which includes the earliest 80% of Earthâs existence. The Precambrian era ranges from about 5 billion to 570 million years ago.This process continues today in such places as Hawaii.he volcanic creation of the Canadian Shield took place during the Earthâs earliest geologic era, the Precambrian, which includes the earliest 80% of Earthâs existence. The Precambrian era ranges from about 5 billion to 570 million years ago.
608 STANDARD. The most common bearing size is the â608.â Characterized by an 8mm core, a 22mm outer diameter and a 7mm width, these bearings are the industry standard and match up with nearly every skate wheel out there. NON-STANDARD Of course, there are exceptions to every rule.
In general, the size of the truck axle should be similar to the width of the skate deck. The majority of trucks are produced to be suitable for most 7.5â to 8â deck sizes. Bushings. Bush ings are rub ber pads between the kingpin and the hanger on a truck.