For locals this is a picturesque fitness circuit. Working in the city I would often ride my bike around this route on my lunch break because it is flat, takes less than an hour and runs along the rivers edge the whole way.
To get a broader view of Perth I suggest hiring a bike and riding around the Swan river and bridges. It’s cheap and there’s a cycle paths all around. From the city you want to ride over the Narrows bridge over to South Perth where you continue East until you get to the Causeway bridge, come back over the river and into the city again.
In the city there is a number of bike shops to hire from, or visit Point Fraser in East Perth and there’s a bike hire place by the Causeway bridge.