It took Portland the better part of a decade to get a bike-share program. It took Portlanders less than a week to start abusing it.

The bike-share system BikeTown is set to launch next week, on July 19. But some opportunistic Portland cyclists are already using the bright orange bike-share racks.

BikeTown this morning tweeted a photo of privately-owned bicycles U-locked to bike-share racks. (The Oregonian first reported on that tweet earlier this afternoon.)

"Please do NOT lock private bikes to #BIKETOWNpdx racks, thank you!" the tweet says. "#CantLockWontLock."

Portland Bureau of Transportation spokesman Dylan Rivera says people are already locking their privately owned bikes to the bright orange BikeTown racks, which are located in 100 areas around downtown Portland and in several neighborhoods.

"These are not for privately owned bicycles," says Rivera. "There are 3,000 public bike racks in the BikeTown service area and more than 6,000 bike racks city wide."

Rivera says the new bike-share system is adding just 100 racks city-wide, and all of those stations are needed to keep the system running.

"It's important that those stations are used just for BikeTown bikes, because we expect to have examples where those stations will be [at] capacity for BikeTown bikes," Rivera says. "We'll need every orange rack we can get."

However, BikeTown says customers ending their ride should feel free to lock the orange Nike bikes to public racks close to the hub for no additional charge. "Look for the racks marked with an orange sticker," says the website.

Rivera doesn't expect any conflicts with this rule, but that like any new system, there's going to be a community learning curve.

"We need everyone's patience and understanding as we learn and adapt BikeTown to Portland," says Rivera.