In principle, hubs can contain any number of bicycles from a minimum of one to tens of bikes.
However, we do recommend to have between 5 to 10 bikes depending on the potential number of users in such area. Unless it makes good sense, try to avoid too large hubs as they could be problematic especially if located on public ground.
In our system, the standard area covered by one Hub is a sphere with a 10 meters radius from the pin dropped on the map. The image below is from our Admin platform, when registering a new hub.