This would be one of my choices.
http://goo.gl/maps/Stojp Access Kedron Brook Bikeway via The Grange and ride all the way to Toombul. Just after the railway bridge turn left and cut through the park to join onto Santgate Road with the flow of traffic as Google Maps doesn't show that bike path. Sandgate road is fast and has its own wide bike lane. Bikes aren't allowed in the tunnel at Toombul so you just stay in the bikelane and go through the surface streets using the bike lane in Nundha Village and back onto Sandgate road. It can be confusing at first but just stay to the bike lane in the far left.




There are a few pinch points. The first is going through Virginia railway station across the bridge where there's no bike line from the traffic lights to the roundabout. There is a bike path that goes from the traffic lights, around the station, under the railway line then back up to the roundabout and across the bridge where you can rejoin the bike lane again. Second is the short bit of road where there's no bikelane between Beams Road and Garazzo Street in the northbound direction. Be wary of the northbound Gateway onramp so claim the lane. The last pinch points are if people park in the breakdown lane through Deagon but you can always turn off onto the side streets depending on where you want to go.
But I would choose this route. No traffic from Grange-Deagon as its all bikeway. Its also more fun to ride especially through the wetlands. Only downside its longer.
http://goo.gl/maps/qy1q4