Toronto's centre trumps the suburbs in the numbers of commuter and utilitarian cyclists, but that doesn't mean there aren't still a lot of cyclists all over the city. The difference, however, between centre and suburbs is that cyclists in the suburbs are spread thinly over an area five times as big as the central urban area.
This is my third map mashup. It compares the share of commuters who are cyclists with the location of Toronto Cyclists Union membership. The map shows that the richest deposits of potential bike union members are where there are already a high number of cycling commuters.
It may come as no surprise that bike shops are located where people bike.