Kathy Marks cocks her head, listening for the din of a thousand bicycle bells. For the Toronto grandmother, it’s a cue to hop on her three-speed bicycle and join a riding protest for more bike lanes in Canada’s largest city.

But after several years of participating in this annual demonstration, she’s considering joining a new group of rabble-rousers to show her dissatisfaction with cycling conditions here: the Toronto Cyclists Union.

“I’ve been riding my bike for nearly 40 years in the city, and it’s high time we have something like a union,” Ms. Marks explained last weekend. “I don’t fly around like the youngsters. But if we were able to have better bike lanes and benefits like a union, you’d see more people out here who are my age.”