Despite not being visible, the bearings are a fundamental component for the proper functioning of the bicycle since the very performance of the bicycle depends largely on them.
There is a lot of bicycle bearing in the market. But when you choose a bearing for your bicycle you you have look on this bicycle bearing kits quality.
They are found in different key parts of it: in the direction, the bushings, the bottom bracket, suspension pivots … and their function is to allow the turning movement between two parts joined by rolling, unlike the bushings of friction that they do by sliding of the contact surfaces. This allows for a smoother turn with less friction so they can turn faster. However, the smaller existing contact surface means that they cannot bear such high loads.
These characteristics make us find different types of bearings for the different pivot points that we can find on the bicycle since the functional requirements are quite different: high turning speed in the wheel axles, high loads and reduced turns in the joints of the wheel. suspension system, axial load steering in direction …
ISB steel bearings
Steel bearings are the most common in bicycles as they are very durable as long as proper cleaning and good lubrication are maintained. They have steel balls located radially inside the tracks or raceways.
They are really very effective, and significantly reduce friction when turning compared to other systems such as bushings.
These bearings are usually sealed in different ways: the RS / RZ, which are the new generation of rubber seal from ISB Sport for bicycle; or the usual ones with rubber (2RS) or metallic covers (the ZZ type), the latter made of the same steel as the rest of the bearing.
If the reference includes the suffix SS, it indicates that both the balls and the steel are made of AISI 420 type stainless steel.
VMax ISB bearings
For the suspension area, bearings have been developed that are capable of supporting certain levels of load, without entailing a significant increase in weight or size. These are the VMax series bearings that have been specially designed for the entire set of the main joint of the swingarm, connecting rod and shock absorber, to withstand reduced turns.
Its main characteristic resides in its special “full ball” design, which consists of the elimination of the usual internal cage that separates the balls and which then allows the insertion of the largest possible number of balls. The tracks of its rims are deeper in order to obtain greater lateral support in the face of torsion and the multiple forces associated with the pivots of the bicycle, especially the mountain.
This series of VMax bearings have up to 35% -40% more load capacity than ISB’s standard series steel bearings. It’s sealing by means of the rubber caps on each side,
Identified as “2RS”, they provide them with maximum protection against external pollutants and allow them to maintain the lubrication that comes from the source.
Ceramic ISB bearings
We call ceramic bearings those bearings in which the usual steel used in their manufacture is replaced by a ceramic material either only in the balls for hybrid bearings or both in the balls and in the tracks for full ceramic bearings.
Normally located on the front and rear wheels, the ceramic bearings are in a position to provide a notable improvement in efficiency, maximizing the performance of the bicycle itself.
Its main advantages compared to standard bearings are, on the one hand, a higher operating speed and, on the other, a longer useful life under the same conditions of use. Its low coefficient of friction (up to 10 times less than in steel bearings) due to the lightness of the balls, provides an extremely smooth operation generating less heating, less wear and therefore, prolonging its durability.
Ceramic balls, being lighter, generate less centrifugal force which translates into less friction and allows the bearings to move faster as they require less energy to maintain speed. Ceramic is highly resistant to oxidation, so its service life is also longer than that of steel bearings. Ceramic balls retain their rolling characteristics longer and do not have the same need for maintenance as steel balls, functioning properly even with a very small amount of lubricating oil.
The higher degree of hardness of this type of bearings requires a more demanding surface finish than steel ones and in the case of hybrids, the much smoother and more resistant ceramic balls, microscopically polish the steel races, improving their finish and producing a smoother roll. Hence the expression that the ceramic balls “clean” the tracks and require a break-in period.
In the ISB series of hybrid bearings under the following SCs, the stainless steel rings are the perfect complement to protect the bearing avoiding corrosion and deterioration caused by the most common external pollutants such as water, dust, mud …
Bearings for ISB steering
The steering of the bicycle is the mechanism housed between the fork and the frame that in turn houses the bearings that allow the fork tube to rotate, allowing the lateral movement of the front wheel and therefore, the change of direction of the bicycle. bike.
To know what type of bearing to use, it is necessary to know that there are 2 types of directions depending on the way it is attached to the frame and the type of power used. The so-called “threaded”
and the “non-threaded” (threadless) or ahead where the fork tube is completely smooth, without any thread.
When talking about the different types of ahead directions, reference is made to the different ways of housing the bearings in the frame, depending on how it is built, to the “head tube”.
• Conventional directions: in frames without internal space to house the cups, in which case the bearings are mounted in the external cups.
• Semi-integrated headsets: in frames that do allow to house the steering cups and the bearings.
• Integrated directions: in which the bearings are mounted directly, without resorting to the use of cups.
These bearings have a special design different from the conventional one that visibly incorporates slight chamfers both inside and outside, whose measurements are determined by
the different grades. Therefore, to choose the most suitable bearings for our direction, it is necessary to take into account the measurements of the inner diameter, the outer diameter, the height and
the contact angles with each of the chamfers.
If we take, for example, the ISB 45º / 45º MH-P08 bearings indicated for ahead directions, the first 45º measurement refers to the internal angle and the second 45º to the external angle. Of all
forms, this information is usually engraved on the outer ring of the bearing itself.
The bearings that are mounted in these types of directions are usually sealed, which avoids recurring maintenance since the grease remains inside, preventing wear on the balls and
extending its useful life. The sealing protects them in addition to the usual pollutants, temperature, dust, humidity, etc …
Despite the fact that the bicycle market includes a large number of measurements for different types of directions, the ISB brand offers a wide selection of measurements and contact angles that place it among the favorites of the most demanding specialist workshops.