While 99% of the bikes in the Brisbane to the Gold Coast Cycle Challenge were drop bar road bikes, I saw probably half a dozen tandem road bikes, mostly with couples on them. They all seemed to be Cannondale bikes.

Cannondale tandem bike at the start of the Brisbane to the Gold Coast Cycle Challenge

Other bikes I spotted included a handful of fixies, a recliner bike, flat bar road bikes and mountain bikes. And there were also a couple of lunatics riding Brisbane City Council City Bikes. I bet they had a blast.