An important piece of the puzzle in Denver's growth as a bike city -- outlined in this week's feature, "On a Roll" -- is the creation of B-cycle, the city's bike-sharing program, which today boasts thousands of annual users. Here, we take you behind the scenes at B-cycle, with a look at some of the weirdest spots the bikes have been left behind and other fun factoids from the Denver Bike Sharing team.

The origin of B-cycle can be traced to the high-profile 2008 Democratic National Convention, when Denver launched a bike-sharing pilot program to help attendees get around. Then-Mayor John Hickenlooper championed the program and decided to push forward with the country's first citywide bike sharing program.

Today, B-cycle has 53 stations across the city and nearly 3,000 annual users who pay $80 for a yearly pass. There are also around 40,000 casual users who can pay $8 for a 24-hour pass. And B-cycle will add another thirty stations by next spring, according to Parry Burnap, executive director of Denver Bike Sharing, the nonprofit group that owns and operates B-cycle.

For the feature, we took a tour of the organization's Larimer Street office, where staff repair broken B-cycle bikes, monitor usage across their stations, help with customer service and more.

The staff provided us with some statistics on usage, as well as some insight into the stranger parts of the job -- the weirdest places the B-cycle team has retrieved left-behind bikes and the oddest objects found in the bike's handy baskets.

Here, courtesy of the staff, are the five most unusual places a B-cycle bike has been found:

• In a garage near the University of Denver when new fall students moved in • Englewood RTD Stop • In Cherry Creek • Boulder • The start line of the 2012 Denver Century

And the most memorable things found in B-cycle baskets?

• $1,200, a Colombian passport and an iPhone • Endless pairs of cheap sunglasses • An elf costume (elf ears and a hat made for putting on a car that someone attached to the B-cycle) • Leftovers • Library books • Coffee cups • Jackets and scarves • Keys and phones

Continue for more statistics on B-cycle usage. One way to measure the growth of biking in Denver is to look at how B-cycle itself has expanded with an increasing demand for bikes.

For the DNC, Burnap -- who headed the convention's Greening Initiative -- and her team were able to secure 1,000 bikes for the roughly 35,000 guests in town for the convention and anyone else who wanted to use them. The bikes were free to ride, and they were stationed at six staffed locations across the city. During the convention, participants logged a total of 5,552 rides totaling 26,463 miles, according to a report on the green initiatives of the DNC. The report also says riders burned an estimated 818,899 calories and prevented approximately 9.3 metric tons of carbon (compared to the same distance being traveled by a car).

The city treated the DNC effort as a mini-pilot for a permanent program, with Hickenlooper saying he wanted 10 percent commuter bike mode share by 2018.

Denver B-cycle officially launched on April 22, 2010 -- Earth Day -- and by the end of the year had 500 bikes spread across fifty stations around town. B-cycle is working to add thirty more stations by next spring.

In 2010, B-cycle had 453 rides per day, according to Burnap. By 2011, that number grew to 748 and in 2012 through October has already logged 844 rides.

Additionally, from January of this year through the 16th of September, 2,493 annual memberships have been sold, along with 31,889 24-hour memberships.

Continue for more facts and photos from B-cycle. Here are some additional stats Burnap sent our way:

Here are the top five most-used B-cycle stations

1.14th & Champa 2. Market Street Station 3. REI (Platte Street) 4. 16th & Little Raven 5. 16th & Platte

And some more miscellaneous factoids:

• The 2,493 annual members take 60 percent of all trips. • The average annual member has taken 37 trips this season. • Annual members' most popular checkout times are morning, noon and after work. • Casual riders' most popular checkout times peak around noon and stay consistent until about 5 p.m., when the rate starts to taper off. • 82 percent of all trips are less than thirty minutes in duration from the moment people check out a bike to the moment they return it.

Burnap says the establishment and expansion of B-cycle, along with the growth of the city's advocacy group BikeDenver and increased commitment from the city to create better bike infrastructure, have all contributed to the city's transformation to better support cycling.

"Putting a physical [bike-sharing] system down with all of the attention that got paid to these red bikes...you can see it, you can feel it...helped turn the volume up on the conversation around bicycles in general," says Burnap "We can't succeed as a bike-sharing system unless BikeDenver is strong as a voice for bicycling, unless the city continues its commitment to investing in bike-friendly infrastructure."

Continue for photos from bikes at the 2008 DNC.

More from our Environment archive: "Cycling: Top twelve intersections for bike-vehicle crashes in Denver"

Follow Sam Levin on Twitter at @SamTLevin. E-mail the author at Sam.Levin@Westword.com.