They plan their gatherings online, using aliases like FatDallas and FatHal. And every Wednesday night, they meet at a nondescript parking lot next to the Assiniboine Forest, disguise themselves with masks and head into the woods to roll a fatty.

No, this isn’t a tale of clandestine drug use. I’m talking about fat bikes, the latest winter sport craze to roll into Winnipeg.

Featuring balloon-like tires at least four inches wide, these bikes can “float” over sections of snow and ice that wouldn’t be passable on a conventional bike.

“Fat bikes are so versatile and fun to ride; in many ways they’re the perfect machine for our winters,” explains Ian Hall (a.k.a. FatIan), who got bit with the fat bike bug two years ago. “They’re becoming really popular. It’s hard to go through a city park or river trail without noticing the distinct tread pattern of those tires.”

While fat bikes can roll over almost anything, there’s a bit of a learning curve associated with them, so Hall and other local enthusiasts established the manitobafatbike.com website to help organize regular group rides and technical practices at Assiniboine Forest.

They’ve also decided to push themselves even further by creating a new winter endurance race that’s scheduled for Feb. 18. Called Actif Epica, the event will take competitors 130 kilometres from St. Malo to Winnipeg via the Crow Wing Trail. Related winter activities will take place at checkpoints along the way, and the finishing line will take riders right up to the snow bar at the Festival du Voyageur site in Whittier Park.

Hall says a fat bike isn’t required for Actif Epica – a regular mountain bike might actually be faster over the designated route – and he suggests the race would be an appropriate challenge for anyone who has completed a marathon, a long bike tour, or similar endurance or adventure racing event.

“We’re calling this a celebration of human resilience,” Hall says. “Winter cyclists rely on others for the trails they use, have faith people will help in case of emergency, take responsibility for themselves by planning and training, and ride a machine that itself is incredibly resilient. Really, these connections and the resilience they create are amazing, and that’s what Actif Epica is all about.”

The entry deadline for Actif Epica is Feb. 13. For more information on the event, see actifepi.ca.