It may come as no surprise that bike shops are located where people bike.
I had previously posted the Census map of bicycle commuters in Toronto. I thought it would be interesting to overlay other information on top. So I created an old fashioned "mashup of the bike shop locations (source: Bike Union website) and the map of the Bicycle Modal Share in Toronto. Not having access to the original census data, I had to just take the image and rotate the bike shop map so it roughly fit the census map. You see the result above.
There seems to be a pretty high correlation between bike shops and commuter cyclists. In a previous post I had wondered why bike shops couldn't survive in the east end. The really low modal split for cyclists in Scarborough gives a pretty good indication, though it appears that there might not be such a big problem in East York and Leslieville.
If were going to open a bike shop I'd look at this map carefully. There are some darker blue spots with few to no bike shops, such as Etobicoke, Toronto Islands, the Portlands and Leaside (I think).
But with the Toronto Islands have restrictions on retail and the Portlands having very few actual residents that leaves Etobicoke, Leaside and a smattering of other spots in North York. Of course, I'd also have to take into account the absolute number of cyclists since the Toronto west end's high density of bike shops still might not be enough. I can't say before looking at the numbers.