Descendant Carbon DUBDescendant carbon crankset uses a proprietary TRUVATIV carbon construction process that delivers a crankset light enough for XC, yet bold enough for Enduro. DUB technology features a better engineered bottom bracket and a new spindle design for a more uniform approach to bottom bracket fitment, better sealing against contamination, and a new measure of durability. SRAM Model ID: FC DESC C B1 Attributes BB Inclusion No BCD Direct Mount SRAM 3 Bolt