I posted this a few weeks ago on 500riders - forgot to post it here.
You can get 1" x 1" x .125" 6061T6 tubing from:
Performance Metals
South Windsor NSW, 2756,
Phone: 024577 7769
Web address:
www.performancemetalsaustralia.com.au
The fellow I spoke to was : Stuart Shackley. They sell by the metre.
They have this in stock pretty much All the time - a very slight radius on the corners and the price per metre is $19.50 (+- a few cents, can't recall exactly) + tax. 1 metre will do the entire cradle of a gen 3 conversion ( I don't lift the Y) - though it would be wise to get more than this for bending purposes / practice , if you've not done one previously.
It's cheap, and easily available guys - you can do a clean conversion with no multiple joints for bugger all. I've just done 2 frames for a couple of mates of mine, 1 being a gen3, the other a gen 4, using just 2 over metres of tubing = less than $46.00 retail in cradle tubing. Sometimes you can get aluminium cheap - this is one size / type that comes under that heading.
With the Gen3, I hoicked it out of the workshop with all the ancillaries to be done by the owner - he's a big boy and should at least do part of his own bike

. With the Gen4 (CRF450x08), the owner is a tech geek ( a handy bloke to have around at times, but next to useless with anything mechanical ) so I'm doing all of his conversion over a few months between other things. With that one I'm doing something very different with the tank & airbox . It should be interesting. I'll post it up if he gives me the go ahead - it's up to him and he might want to have something unique - I owe him a hell of a lot in many ways, so I'll only show it if he OKs it.