What does the central axis of a bicycle mean?

The central shaft is a rotating part installed in the five-way of the frame, which is used to connect the left and right cranks. There are three common sports cars: square hole, spline and integral type.

The central axis of a square hole is the most common, because both ends are square, so it is easy to identify. It is improved on the basis of traditional pin shaft. The pin shaft is locked by a single pin, and the contact surface is small, which is easy to loosen and damage. Now it can only be seen on quite old civilian cars.

Just a few years after the introduction of spline shaft, various manufacturers have introduced the concept of integrated shaft and produced it in its high-end series. The so-called integration means that the axis of the central shaft is separated from the bearing and directly combined with the crank on one side to move the position of the bearing from five directions to two sides.

Extended data:

The middle axle of a bicycle can also be regarded as a consumable or a worn product. Riding for a period of time or a distance needs maintenance or replacement. There are also many types of shafts, which can be basically divided into several types from the specific form of shafts, such as bead shaft, integrated shaft and through shaft. At present, the central shaft of the bead block is basically eliminated, and the integrated shaft and the through shaft are the most used.

Generally, the integrated central shaft needs to be maintained once a year and replaced every three years. If there is abnormal sound or the bearing is stuck in use, it also needs to be replaced. Whether it is maintenance or replacement, disassembly is an energy-consuming process.

Cleaning and maintenance of central shaft:

1. Clean the spiral teeth in the five-way and central shaft of the frame, which is an important source of abnormal noise. This part of the gap will hide a lot of fine sediment, which needs to be carefully removed with a brush.

2. Apply a little grease after brushing, and choose grease with good water resistance and high viscosity. Other parts should also be cleaned, so as to ensure that all the sediments are cleaned, and the axis should be coated with grease, and then the axis and crank should be put back.

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