Swapping frame pivot bearings
Frame pivot bearings are one of the most stressed bearings on your mountain bike. Every bend you take stresses the frame pivot to some degree, depending on the velocity and tilting angle. The rear frame pivot bearing must also cope with the impact from stones, rocks and tree roots on trails. Furthermore, because these bearings only make swivel movements, rather than fully rotate, it is nearly impossible to provide adequate lubrication. And it is exactly this that leads to premature bearing failure.
To handle this, have a look at our tutorials for replacing frame pivot bearings.