Just when it looked like Dara Khosrowshahi’s tenure as CEO of Uber was coming into focus, the genial executive has muddied the water by buying, of all things, a bike-sharing startup called Jump.

Everything about Uber since Khosrowshahi took over suggested prudent pruning. He painstakingly cleaned up one of the messiest boards in corporate history. He sealed a deal with mighty SoftBank as both an investor and an ATM for existing shareholders, including former CEO Travis Kalanick. Khosrowshahi, a former CEO of travel site Expedia, deftly settled an acrimonious lawsuit with Google’s former self-driving car unit. He exited Southeast Asia by selling to regional leader Grab. (That deal might have hit some speed bumps, however.) The new Uber CEO even is quietly shuttering once-ballyhooed distractions, including Rush, a delivery service.

Indeed, a close read of an entertaining profile of Khosrowshahi in The New Yorker, suggests the former investment banker even has cast a jaundiced eye at Uber’s existentially important autonomous vehicle program. The penultimate paragraph suggests he still isn’t committed to it.

All this makes it all the more surprising that he’d complicate matters by buying Jump. Yes, bike sharing is all the rage, particularly in China, whose e-commerce leaders are investing in the U.S. market. Jump is problematic at multiple levels. It owns its own bikes; Uber’s business is based on using someone else’s vehicles. The bike-sharing business represents a new regulatory challenge. And its economics are unproven at a time Uber has yet to prove its own business model.