India, Sept. 11 -- In April 2016, a bike taxi startup barely a few months old persuaded some established names in Indian business to back the idea of sharing a motorcycle ride. Hero MotoCorp's Pawan Munjal, Google's Rajan Anandan and People Group founder Anupam Mittal were among the investors in Rapido's pre-Series A round.

Its founders, Aravind Sanka, Pavan Guntupalli and Rishikesh SR, had early evidence that the idea could find takers. The funding would help them take the service to more cities and build the team.

The trio's earlier logistics venture, Karrier, had shut down. This time, the proposition was simple. A motorcycle had a spare seat, its owner could use some extra income, and someone nearby needed an affordable ride. Rapido'...