In the tear-soaked jigsaw puzzle that is New York City transit, the news out of Citi Bike can often feel like a rare cause for optimism: Annual membership is up 11.8 percent since last year, a major expansion is planned for next year, and the early reviews for pedal-assist are overwhelmingly positive. For now, the biggest problem facing city bike-share would seem to be figuring out how to expand the system to other New Yorkers clamoring for access.

Why, then, did Citi Bike remove nearly 2,000 bikes from the city's streets?

The company isn't really saying. In an email sent to customers on Wednesday, Citi Bike acknowledged the "lower-than-usual levels of bike availability," which they blame on "unusual damage on some of our handlebars." A spokesperson for Motivate—which owns Citi Bike, and was recently purchased by Lyft—declined to answer follow-up questions about what the "unusual" damage entailed. Reached by phone, a Citi Bike customer service representative told Gothamist, "the email that was sent out is all that we can say at this time."

Beyond the mysterious damage, the service alert notes that the bikes are being retrofit with a new handlebar style, a process that is taking longer than expected. "We're devoting extra resources to this issue and expect you will see an improvement in bike availability soon," the statement assures.

But a Streetsblog report published earlier today suggests that Citi Bike may be underselling the extent of the shortage. According to the company's own data, the number of in-service bikes has decreased by 21 percent, from 9,112 to 7,166, in just the last two weeks.

Despite this, Motivate still claims to be meeting its promise to keep 12,000 bikes on the street—a threshold mandated by the company's contract with the city, which grants Citi Bike a monopoly throughout much of New York. We've asked City Hall whether they're aware of the vanishing bikes, and we'll update if we hear back.

In the meantime, New Yorkers are starting to feel the effects of the system-wide Citi Bike shortage and—considering the other available options for getting around the city right now—they're understandably pretty pissed.