Prototype Blackbox Rear Derailleur and 7-Speed Cassette on Sam Hill's Bike 1

Sam Hill, Steve Smith, and Aaron Gwin are running some miniaturized XX1-style derailleurs. Just like XX1, they use SRAM's straight parallelogram movement, which helps prevent skipping. They're also quipped with a clutch to limit chainslap, and all of the boys had 7-speed cassettes as well.