What type of development showed that the idea of indexing was not centralized in one corporate R&D department?

Answer

Grassroots efforts resulting in bar-mounted index shifting

Evidence of an individual's brother developing bar-mounted indexed shifting highlights that the concept was being sought simultaneously by various enthusiasts or racers outside of major corporate research.

What type of development showed that the idea of indexing was not centralized in one corporate R&D department?
inventiontechnologymechanismbicycleshifter