Polymer plain bearings in mountain bikes with spring-loaded rear wheels

Selection of the articulation points and kinematics

In the field of Bergamont's full suspension mountain bikes, "ConTrail MGN" is one of the top models. At the dropouts of the rear suspension, lightweight iglidur polymer plain bearings from igus are used for heavy duty applications. When designing a rear suspension, the definition of the pivot points plays a very important role. Thomas Marquardt: "We have a clear understanding of how a bike should run and carry out extensive testing during development." This not only applies to the placement of the pivot points and to the kinematics, but also to the selection of the bearing points. At all bearing points Bergamont originally used its "Fullys" ball bearings. For the first time, the "Contrail MGN" has deviated from this principle. "At the two front pivot points," says Marquardt, "that is, when connecting the rocker to the frame, we use deep groove ball bearings because the bearings here make a relatively large pivoting movement. On the rear joint, in the rear axle, this time we have departed from the old method and use a plain bearing. “

Dealers and bikers fully satisfied

The self-lubricating iglidur polymer plain bearings can be expected to have a long,  calculable service life. However, the sales department had to first convince the specialist dealers. Thomas Marquardt: "Several years ago, we used plain bearings made of other materials and were too small in size." Therefore, there was now need for information and training. " With the current solution, however, the dealers are fully satisfied, as the feedback from the bike owners are consistently positive. The torsional rigidity of the wheel was very good and the suspension responded very quickly" reports Marquardt.  
 
This certainly also contributes to the very careful design of the bearing point. In bike production, the plain bearings are pressed into the rocker with slight pressure. In addition, a metal sleeve is inserted into the bearing, which forms the end stop for tightening the screws. So the bearings remain rotatable in any case after assembly work of the bike owner.   

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