These bearings are made of high-quality bearing steel long life with low noise.
Hubs Bearing Guide
The hub is the central part of your bikes wheels (front and rear), which connects to the wheels rim via the spokes and through which the axle is fitted, enabling the wheel to freely spin on two sets of bearings.
As bikes have front and rear wheels, so too have they front- and rear-specific hubs. The front hub is simply designed to enable the wheel to spin, while the rear hub is a little more complex as it also forms part of the bikes transmission ? the cassette or sprocket which drives the rear wheel is attached to the rear hub, which on most bikes also features mechanism to allow you to coast or freewheel (exceptions being fixed-gear or fixie bikes and track bikes).
Your wheels spin more than any other part of your bike. Therefore, having the best bearings in this application is crucial to producing the best results.
Grease
They are characterized by excellent water resistance and load-carrying properties and help provide long-term protection against rust and corrosion.
Bearing Installation and Removal
Bearings should never be installed by pressing on the inner race.
Always press on the outer race with a pilot bushing or similar tool, which will only make contact with the metal side of the outer race.
A bearing press or similar should be used to exert the force needed to press the bearing into the housing.
Ensure that the seating surface is clean and free from rough edges so that they fit true and square.
Quite often bearings can feel fine before fitting, but then feel "notchy" or "rough" after fitting. This is almost always due to the bearings not sitting square and true.
Care needs to be taken that the bearing is started straight and not at an angle to the housing.
Bearing CareTo prolong the life of your bearings, do not direct a high jet of water near areas of your bike where