Bicycle Frame

any beach cruiser frame usually works well most Schwinn and smiler bikes and larger frame ridged mountain bikes

Have you tried hanging around outside your local tip? Admittedly, you end up loking homeless and disreputable, but people throw some near new things away these days.

And what's your local equivalent of car boot sales, flea markets etc?

Also to consider, it must be the same the world over, police recovered stolen property auctions. Not everything can be traced back to it's owner. The nearest one to me sees up to 10 bicycles going as a job lot for £100.

There are quite a few guys on the forum from down under, post a wanted in the swap and shop. You will get some help too.

Here's one of the newer things Kings has been selling:

http://www.kingsmotorbikes.com/alum-bike-frame-gt2a-s.htm

an aluminum cruiser frame with a built in tank

Looked around a bit at Craigslist/ Sydny- looks a bit sparse, like just getting going- it's a bigger deal here in the states and agreat place to get bike stuff locally.

Beach cruisers are good because theyhave lots of clearance- a lot of people use mountain bikes. I think a freewheel hub is easier to mount a sprocket on, but gotta have some caliper brakes squared away-

Good luck mate, my mother was from Bundaberg Queensland.