KITCHENER, Ontario — Andrew Flemming and Geoff Fowler tinkered for months in their spare time. They used soldering irons. They printed three-dimensional models in their basements. They brainstormed over beers in this small city about 60 miles west of Toronto, where they kept their project quiet.

“We did a fair bit of work in bars,” Flemming said.

Flemming and Fowler, both 29, along with their friend and business partner, Will Hamilton, 37, were pouring their creative energies into a high-tech training device the likes of which the sporting world had never seen.

They were building a better broom.

Not just any broom, but one that they thought could be essential to the sport of curling, which relies on the best broom handling out there as teams strategically cajole a polished granite rock across a sheet of ice.

They wound up calling it the SmartBroom, and in a sport that can come across as vaguely primordial, their piece of 21st-century gadgetry could play a role in determining who wins gold at the 2018 Winter Olympics in Pyeongchang, South Korea.