What kinds of roller skates are there? Please introduce it in detail.

The classification of roller skates includes: speed skating shoes, flat shoes, extreme shoes, downhill shoes, casual shoes and cross-country shoes. The length of the tool rest is generally 227 to 243MM, with two big wheels in the middle and two small wheels in the front and back. According to the length of the tool rest, the diameter of the grinding wheel is also different. Usually 76 to 80 mm. Casual shoes: Knife rest is longer than flat shoes, but the wheel size is not necessarily the same. Generally larger than flat shoes and smaller than speed skating shoes. Speed skating: No matter whether the tool rest is longer, four wheels or five wheels have their own advantages and uses. Speed skating is divided into different venues and horses. Loose extreme shoes: Generally, the different wheels of the tool rest are two wheels, with two wheels and two extreme plastic small wheels. Cross-country shoes: the tool rest is long, with two inflatable wheels in front and back, and there are also shoes that play roller skating and are even, but the performance of the shoes is required to be stronger. The whole shoes look much better than plain flowers! The structure of the wheels is also different. Generally, the big one is used in the back and the small one is used in the front!