Enduro's top of the line BB solution, "Corsa" XD-15 bearings are not standard "cartridges." They are a special cup and cone configuration using high-nitrogen steel races and Silicon Nitride Grade 3 ceramic balls that Bike Radar called "Hands down, the best bottom bracket we have ever tested." Enduro XD-15 bottom brackets and bearings are manufactured to the highest standards at the Enduro Bearings production facility in California, USA.

XD-15 corrosion-proof bearings only get better with use. As the bearings wear-in, the balls actually make the races even smoother. So when compared to other ceramic-hybrid bearings on the market that claim speed and power advantages on day one, Enduro XD-15 bearings not only provide the same initial advantages, but will get even faster and smoother with use.

If you find these claims hard to believe, consider Enduro's lifetime guarantee against wear and corrosion on the XD-15 Corsa bearings.