Generally, there are two kinds of bearings on bicycles: bearing and ball bearing. In addition, there is a wonderful work of needle rolling, which will not be discussed here. This problem mainly focuses on flower drum. The bearings in these places have requirements for the lubrication degree and the stress intensity of axial force and radial force at the same time. For places like the turning point of the frame shock absorber, the radial force is mainly considered, so almost all of them are bearing. It is customary to call the flower drum that is independently embedded in the bearing assembly bearing. The bell bowl is inserted at both ends of the flower drum, and the ball is discharged into the bell bowl. The bearing that is driven by the rotation of the ball is called “ball stop”.
Generally speaking, bearing can be disassembled as a whole and become the annular “ball bearing” that everyone usually sees. At first, the basic problem is that the bearing force of bicycle axle is divided into radial force and axial force. 1. When the shaft bears the radial force, there is little difference between the two. However, in terms of the axial force, the bead retaining structure has a bead bowl, so theoretically it can withstand greater axial force and higher strength. 2. In terms of lubrication, the bearing is generally 7-8 balls, and the upper and lower parts of the ball with cage are the slideways of the inner jacket (see the first picture). The wrapping character is closer to the hemispherical shape, which makes the rolling smoothness better. Since there is no cage in the ball stop structure, the ball can reach more than 9 balls. When the grinding accuracy is the same, the rolling resistance of this structure is more than that of the assembly bearing with 7 balls. 3. Due to the good sealing property of bearing, it is not easy to enter water and sand, so bearing can provide a better life without considering the high cost of solving the sealing property. In the above three points, the second and third points seem to favor bearing. But both are based on the consideration of cost. In fact, in order to ensure the strength, lubrication and sealing of the bearing in the advanced wheel set, the cost will not be compromised.
For example, Shimano’s XT and XT, ball and file are all laser processed, with very high accuracy. This also leads to the irreplaceability of these accessories: each flower drum is unique, and each accessory is adjusted according to the actual situation. To sum up, if we do not consider the price, but only consider the strength, lubrication and sealing, the bead stop structure has a perfect solution, while bearing can only solve the lubrication and sealing. In view of the beaded drum structure, we should take all aspects into account, and the cost is very high, so the common bearings of bicycles are bearing. However, Shimano XT/XTR, SRAM CR and other high-end wheels, which can ignore the cost to some extent, are all made of bead block structures. FULCRUM F0 is not a simple alternative, but a more complex solution. You are interested in checking the information yourself