CyclingGravel has been out and about and is always good for ideas. This route is from National Arboretum to Campbell via Black Mountain and Ainslie. The route is found in Komoot and on the website. If you do not mind the suburbs this is a good ride.
“OK, so not entirely boring, but not gravel. This route takes you through some of the older streets of the city, delivering an experience of the layout of some of Walter Burley Griffin’s original street designs. The suburbs also have some of the original (or close to original) houses of the city, as well as some new (and expensive) rebuilds. Don’t forget to sticky-beak at Lego House, which is on Masson Street.”Arboretum to Russell, CyclingGravel, 15 July 2020, accessed 24/7/2020
The map of the route is shown below on Komoot.