There is an empty market niche for a neighbourhood mechanic who accepts a bike in the evening and returns it in the morning. The demand is concentrated almost entirely outside business hours – evening, early morning, weekend. Opening the residential neighbourhood shop at those times would target cyclists whose bike breaks down on the commute from work to home. An overnight fix means they would not miss their next morning’s ride and would not have to haul the bike to a city shop by some other transportation.
Currently the neighbourhood shops I have seen are open during regular business hours, perhaps close a little later and open also on the weekend. I have not checked, but they must be almost customerless in the daytime on weekdays. People go to work or school. I doubt there are enough stay-at-homes who bike enough to require a mechanic’s services frequently. People in the city may visit a city bike shop at lunch, but not a residential neighbourhood one. The local shops seem to be open exactly when the customers are not there.
Fixing a bike takes time, so cyclists leave it in the shop and come back later. It is important which time of the day the bike spends at the mechanic’s. Customers who use their bike a lot and thus need frequent service want the bike available and working mainly during rush hours, because many of them commute with it. A city bike shop open during business hours can accept a bike in the morning, fix it and give it back by the end of the workday. For the commuter, the bike is available both morning and evening. The shop does not need to store the bike overnight, so does not need to rent a large space, saving costs. In a suburban shop, customers could leave their bike one evening and pick it up the next evening, but they could not use their bike for one day’s commute then.
Load sharing between city and suburban bike shops is possible. Mechanics can work in several shops at different times. They can shift to accommodate peak demand, the timing of which differs by shop. The residential neighbourhood shop would get the most customers on the weekend or outside business hours. The city centre would get more on weekdays in the daytime (the cyclists whose bike breaks down on the way to work).