Are bottom bracket options driving you mad Do you feel like a puppet in the hands of frame manufacturers who change specs yearly Do you want to use your existing BB24 crankset on your new mountain bike rig, but it just doesn't fit Not to fear, Rotor's BB30 to BB24 Converter has your back. Using non contact labyrinth seals, Rotor created a bottom bracket converter that's buttery smooth. Although not other worldly technology no goblins were harmed in its design, labyrinth seals have a maze of grooves or teeth where the male and female pieces slip together, often perpendicular to the threads. These grooves create a torturous path that fluid would need to pass through. This, creates a near leak proof seal. Additionally, the labyrinth seals provide unparalleled protection from elements such as dust, water, and mud, as it cannot pass through the seals. The BB24 converter is only available with steel bearings. It will accept all conventional BB24 cranks from Rotor, Shimano and Shimano compatible brands. It weighs 120grams and is available in Black.