We rode from Cammeray to Lane Cove Park a few months back. It’s a great circuit. I recommend that you start near Tunks Park and make your way to the trails under the freeway. You then branch of towards Chatswood and the paths winding up to Chatswood are really nice. Near Chatwwood there are some well signposted roads to get you to near the station. We then headed down the steep hill into Lane Cove National Park and rode to the far end and had lunch at the garden centre. We returned to the centre of Lane Cove National park and made our way up to North Ryde Station. We caught the train to Chatswood. We then rode back along the trails to the top of Tunks Park and the Long Gully bridge. Great trail for commuters and joy riders to learn.
See the Purple trail in Google Maps here in the Northern Sydney Maps >>