They're calling it 'Tinsanity' – a fat bike race around Yellowknife's Tin Can Hill.
The event, hosted by the Yellowknife Mountain Bike Club, takes place on Sunday, January 20.
Riders of fat bikes, which have specially widened tires to cope with winter conditions, will complete as many two-kilometre laps of the hill as they can in a set time limit.
Depending on how long you want to ride, you can choose either 40 minutes or one hour as your time limit to complete those laps.
Registration costs $10, payable in cash. You can register from 10:30-10:55am on Sunday, with the race starting at 11am. (You need to have your own fat bike, and helmet, to take part.)
Spectators are welcome and conditions in Yellowknife are set to significantly improve by Sunday, with a forecast high of -23C with flurries.
"The intent is for the event to go forward, regardless of how cold it is," said Shannon Jennings, one of the organizers.
"When it's been minus-35 a couple of weeks in the past month or two, we still had group rides. There were about three people on those rides, but they are still going for it."
A warmed tent will be available on-site for competitors.
Describing the course, Jennings told Cabin Radio: "There's a long climb involved. I expect a lot of participants to get off their bikes and run up the hill. It's a two-kilometre loop, do as many loops as you can in the time limit. "
Advocating for the fat bike as a mode of transport, she continued: "I used to ride to work across town on a road bike. I did that for a year or two but you get to your destination and your nerves are so shot from being so hyper-vigilant that you're going to get stuck in a snowbank and tipped over.
"You just float on a fat bike," she added.
The club is encouraging people to take out annual membership – at $20 – when they turn up for the event, to support projects like the development of a new bike park for the city. Members race for free.
World Snow Day
The event takes place on World Snow Day, which sees a range of other snowsports and wintry activities available at no cost elsewhere in Yellowknife.
Yellowknife Ski Club is offering a pancake breakfast at the ski chalet from 10am till 3pm, with no fees to pay for using the trails, plus ski and snowshoe rental.
From 1-3pm, there's a pick-up game of ultimate at Somba K'e Civic Plaza, plus snow volleyball and hockey.
Also at 1pm, meet at the Wildcat Café for a guided walk to the ice caves organized by Ecology North.
Meet at Frame Lake by the skating oval at 1pm for a group snowmobile outing with the Great Slave Snowmobile Association.
And from 1-4pm there's a snowboarding demonstration session organized by the Ragged Riders club at Bristol Pit.