The unit does not need modifications to the housing/cassette, so it is retrofitable to existing factory designs.
The external patented profile of the Outer Ring SKF Kart Unit has small grooves with sharp edge along them. This particular geometry increases the resistance to the misalignment of the bearing in respect of the cassette when driving the Kart. The SKF geometry assures the bearing much more grip inside the aluminium/magnesium cassette.
By using ceramic balls it is possible to decrease friction, weight and increase hardness with the result of lower running friction even with little quantity of lubricant.