Boulder Cruiser Ride The Boulder Cruiser Ride happens every Thursday evening from spring through fall. Meeting places and times vary depending on the week. Upcoming themes: July 15 — Roman toga ride July 22 — Christmas in July July 29 — Open theme Aug. 5 — Circus ride Aug. 12 — Undergarments ride Aug. 19 — Zoo ride Aug. 26 — Open theme Sept. 2 — I love the 80s Sept. 9 — Marathon ride Sept. 16 — Bike like a pirate day Sept. 23 — Trailer park trash ride Sept. 30 — Glow ride Oct. 7 — Cruiser jam For more information, visit cruiserbikeride.org.

By 8 p.m. Thursday, more than 100 people had gathered at Scott Carpenter Park for the weekly Boulder Cruiser Ride — including two police officers who were slowly crisscrossing the grass on their own bikes.

In the past few weeks, officers have started pedaling along with the large Thursday night rides after receiving several complaints about the cyclists disobeying traffic laws, congregating on the Boulder Creek Path and drinking alcohol while biking.

Since two to four officers started biking along with the cruiser ride, which can grow to 400 riders or more on any given Thursday night, about a dozen participants have been ticketed — mostly for having open containers of alcohol, said Boulder police night Cmdr. Curt Johnson.

“In the last couple of years, it’s grown in great popularity,” Johnson said. “This year we felt that we needed to have some presence there and get the message across that you can’t just blatantly disobey laws and ride around drinking alcohol.”

This Thursday’s gathering was relatively paltry in size, and while a rainy weather forecast might have kept some away, Boulder High students Scott Collins and Casey Calpin said they think the shrinking turnout was related to the new police presence. But the uniformed bike riders haven’t kept them from showing up for the ride.

“We don’t drink and we don’t do drugs, so we’re fine,” said Calpin, who will be a junior in the fall.

Organizers of the ride say they want to work with police to make sure riders are participating in true cruiser spirit, celebrating bikes, community and Thursday nights, while obeying traffic laws and equipping their rides with lights.

“The big thing we are promoting is being in control, staying to the right and having a light,” said Chris Vinall, a volunteer helper in organizing the weekly ride. “We try to be self-policing as much as we can. For the most part, people are on board with that and want to make it happen.”

The original cruiser ride started in the mid-1990s by a group of friends who wanted to show off their brightly colored, souped-up cruiser bikes — sometimes while in costume — by riding aimlessly around Boulder every Thursday.

The ride has grown large enough in recent years that Vinall said there are now offshoots of the original event.

“To say that there is one Thursday night ride every week isn’t really true anymore,” he said. “There are multiple rides going on that people have started on their own.”

Sometimes, Vinall conceded, it’s difficult to get everyone to share the same cooperative mindset.

“The unfortunate side is that you have folks doing their own things and going on their own rules,” he said. “It might not be in the cruiser spirit. It’s hard to get the message out there.”

Ash Holcomb, who says he helped found the original cruiser ride, thinks the splintering of the ride into separate cliques is, itself, a violation of the cruiser spirit. He believes the original cast of wacky cruisers plans its own meeting place via a secret e-mail list, and that bothers him.

“This,” he said, looking around Scott Carpenter Park on Thursday night at the largely teenaged crowd, “is now the proletariat of the cruiser ride.”

Holcomb — who showed up with his 1952 black Schwinn — also thinks it’s a good thing for the police to ride along. They’re part of the community, after all.

“They’re good riders,” he said. “And they’re good dancers, when we stop to do a dance party.”