I live in a city with a bike-sharing system. It's deeply unprofitable and exists only at the sufferance of the city government. There are a number of flaws. Number 1 is that people who ride bikes don't rent them, they own them. For $100 anyone can purchase a bicycle that will last indefinitely and be available 24/7/365. Number 2 is that people vandalize the shit out of bicycles. Seats will be stolen, tires slashed, bicycles thrown in the river, cables cut. You're free to go after this sort of bicycle since it has no owner - no one is going to come storming out of a nearby store and kick your ass. Crackheads will steal a bicycle seat and try to sell it for $5 to get a hit of crack - I have watched them do it. We live in a world where people are routinely electrocuted trying to steal copper from live power wires and blown up stealing gasoline from pipelines. Those bikes might as well have a sign on them saying "steal me". If even ONE of the components can be removed and sold for a few dollars...
http://www.theglobeandmail.com/news/world/pariss-pedal-power...
http://www.cbc.ca/news/canada/montreal/story/2009/06/26/mont...
Combining high cost of bicycles, ongoing cost to repair/replace/corral wayward bicycles, and low cost of the alternative (owning a bicycle), there is just no chance that this can be a successful business. You will recall people talking about the future of electricity, as being "too cheap to meter". Well, electricity never made it that far, but time on a bicycle did. Bicycle-time is too cheap to meter.
(There may be some future for the company selling to cities or other large entities which intend to subsidize all the costs associated, but it can never be successful as a stand-alone business.)