Also, while the idea of being on the trail appeals, you will get a lot of people who browse, not buy -- I won't buy new shoes, for example, if I am riding, because I won't have anywhere to put them. So I might look, try something on, and them move on.
This is to make the store as accessible as possible for cyclists....who bike like me to do errands /don't have a car /near a very heavily used bike path and if you want to encourage others to bike for transportation/daily lifestsyle (and they tend to have a carrier, pannier racks, etc.). Trail was intended to mean more a defined bike path for commuters.

The most well-known and used bike stores where I've lived and biked in Toronto (14 yrs.), Vancouver (8 yrs.) and Calgary are all with half km. or right along a marked bike route. Sure you get people who browse, look around and won't buy..but you will also get more people who will buy and prefer safety/convenience of cycling on bike paths, bike lanes, instead of far flung mall locations with no safe cycling access.