Your guide to cycling in & around Brisbane
The trip to Lake Samsonvale is roughly ten kilometres from Petrie station, and is cycleway for the most of the journey.
It's a pleasant trip to the lake, although as you might expect the journey involves climbing a few hills, particularly as you get closer to the dam. The dam is about forty-five metres above sea level and the railway station is about ten, so there's a fair amount of hills involved, but none are overly steep and the only truly "get-off-and-push" stretch is the sixteen-metre uphill right after you cross the North Pine River.
The final leg of the journey requires some road cycling although this mainly involves residential back-streets aside for a 150 metre stretch along Forgan Road to get to Bullocky Rest.
Bullocky Rest is a large picnic area on the eastern bank of Lake Samsonvale. It's a great place to have lunch or spend an evening, although you will need to bring your own food as there are no shops within cycling distance.
The picnic area has the usual facilities including picnic tables, electric barbecues, toilets and fresh drinking water. There's also playgrounds and bushwalks if you're feeling adventurous.
This is a reasonably intense trip, so you probably shouldn't attempt it if you're new to cycling. There are no hazards to take care of, although you should be wary of your speed on the trip back down.