On a crisp 9-degree night in mid-January, while hundreds nearby marched through another midweek evening commute, several dozen cyclists and their beefy rides descended onto the grounds of a small north metro park.

Some people huddled by a small fire, greeting one another. Others double-checked gear: helmets, bike CatEye lights, tire pressure. Under a brilliant full moon that hung like a lantern, their numbers increased as more eased into and populated the mini-encampment near a park parking lot. It was close to race time.

When the hour neared 7, they lined up, riders and their bikes alight against the night. Then, with a pre-race cheer, they were off, pedaling and kicking up snow with their big knobby treads, and spreading out into the dark horizon.

You can fight winter, or you can choose to roll with it.

Some fat bikers are choosing the latter on their Wednesdays in January and February — what’s become their Fat Wednesdays — at a race where they propel their ever-popular fat steeds over Keller Regional Park in Maplewood. The thrill of night riding, a laid-back atmosphere and an after-party that delivers good times (and good beer and soup) are a winning combination that entices veterans and newcomers.

Fat Wednesday launched its third season Jan. 11. The first race, scheduled Jan. 4, was canceled owing to unsafe, icy conditions, but Minnesota’s uncooperative winter hasn’t dulled enthusiasm. The tone was set early by the race’s energetic director, Jeremy Sartain, 42. He welcomed the riders, informed them of sketchy patches on the 1¾-mile course, and then reminded them of the party to follow inside the renovated Keller Golf Course clubhouse, which looked inviting on its point across Hwy. 61. Plus, there was swag to give away, from winter caps to high-end studded tires.

Finally, at Sartain’s command, the fat bikers were off in fits and spurts. Some put the hammer down, while others were on a learning curve inherent in a relatively new sport. A few had never ridden fat bikes, whose low-pressure tires float over snow. Fat Wednesday riders more-so compete against the clock, and have the option of riding “short and fat” (30 minutes) or “open fat” (60 minutes). The idea is to ride as many loops as possible. But, really, results are secondary, and that vibe contributes to the night’s popularity.

Once the race began and riders morphed into small beacons of light on the distant horizon, the race found its rhythm. Twelve riders were in the open; 16 riders in the short. (“On the max end, 50 is kind of comfortable,” Sartain said). Some of the small band of volunteers who help Sartain groom and set up the course, like his comrade Brendon O’Flanagan, also stood in the chilly night near the finish line to track riders and their laps.

Several riders in the short race hung around to shout encouragement to their fellow riders, who bore down on the finish, grinding through the chopped-up snow. Forty minutes in, some of the tops riders had completed four laps.

“Show up and finish. That’s my goal,” said one as he ended his night. “That was work!” shouted another.

“It’s where I want it to be. This is great,” Sartain said of the turnout and the race, given a recent snow that made driving dicey and an ice storm that helped cancel the opener.

Staying true

Sartain is friendly and self-deprecating. He also is a detail-oriented, and keeps a watchful eye on his course and his riders. From burning his free time to prepare the course each week to keeping the mood festive in the Keller clubhouse, he has tried to stay true to the event he hatched with Steve Hed several years ago. It was then that Hed, a visionary in the world of bike wheel design, met Sartain as his massage therapy patient. Hed talked with Sartain, also a cycling loyalist, about putting together a community night race for fat bikes. Hed died suddenly at age 59 in November 2014. The first Fat Wednesday rolled in January 2015.

The races ran the first year at Turtle Lake in Shoreview before moving to Keller. Sartain has worked closely with Ramsey County Parks, which owns Keller Golf Course, and Lancer Catering, which manages the clubhouse’s food service. Parks officials asked for responsible use and behavior at Keller Park, and Sartain has delivered. NOW Bikes, too, is a key ally, providing demo bikes and other support.

“I think what we’re trying to do is let this event tell us what it’s going to be when it grows up, but we’ll also give it some parental guidance if it gets out of control,” Sartain said with a laugh. “We don’t want it to lose this organic, social feel that it has.”

Twenty dollars gets an entrant a night of riding, and keeps the good times rolling. It’s an event with a heart, too. Proceeds go to nonprofits. Last January, one of the races benefited the National Alliance on Mental Illness in Minnesota. It was a memorial ride for Benjamin Erickson, who was well-liked in the cycling community. His family attended the race, and Sartain dropped off a $700 check with the NAMI Minnesota director. True to his modesty, Sartain made a point to applaud the riders in a post on the Fat Wednesday Facebook page. “I didn’t do this — you all did.”

“I want to have fun with it, too,” Sartain said. “This is just a hobby.”

More like a club

Later, inside the warmth and warm wood of the history-rich Keller clubhouse, contented riders unwound with a keg of Surly, soup and an easy camaraderie.

Cheeks rosy and stretched by a smile, Terri Johnson, 56, of Plymouth, is a mountain biker who converts to fat tires in winters. She was in her second season of Fat Wednesdays, and is loving it. “This was trying tonight, so that makes you doubt your abilities,” she said. “But once I get out and doing it, it’s more fun.”

Her friend Sara Wefel Collison, of Independence, sat nearby, leaning into some postrace nourishment. She said the Wednesday night event is ideal on multiple levels: a good time of day in her schedule (she is a busy equine veterinarian) and a ride that she can take at her own pace.

After making some small forays into informal ladies’ rides with rented gear, Wefel Collison said she wanted more. She bought a Surly Pugsley in December 2015, and has jumped into mountain bike races like Lutsen’s. “Fat tire biking for me has been my gateway drug.”

Fat Wednesday supplied some of that adrenaline. Wefel Collison rode for 30 minutes.

“It was great. Everyone is really, really nice. It’s super low-key,” Wefel Collison said. “You can go out there to work on just fine-tuning your bike, just finding confidence. There’s a challenge in it no matter what your skill set.”

Nick de Julio and Andrew Tubesing, both of St. Paul, shared a beer and conversation with Jeff Schmieg of St. Louis Park. They’d all met at Fat Wednesday, driven to attend by different motivations, and now enjoying the casual connectedness that fat biking — and, well, most recreational sports — inspire. De Julio, 35, was looking for easier events after buying a fat tire bike. “I was like ‘Oh, Wednesday .... This is in my neighborhood.’ ”

Tubesing, 47, said that while fat biking opportunities now are all over the calendar Sartain is producing something extraordinary.

“He does such great things, and he has got lots of interesting bike things going on,” said Tubesing, who brought some first-timers with him. “Even if I didn’t care about biking I would come to support what he is doing anyway. He is a really connected and interesting person who is always doing something that matters.”

“Just looking around tonight, there are a lot of new faces,” De Julio added. “(Sartain’s) helping people get into it.”