I tried fresh tempering the seat mount tubes, they still cracked. The fold is along the grain of the tube and its also a zero bend radius fold. The only solutions I can see are to put and inserts inside the tube (similar to the pushrods in this post) or to file the cracked area away once the flattening is done. Last night I formed the clamps for around the seat tube. I used the flattened tube I made earlier to test the setup. The plans call for the length of the flattened support tubes to suit. I guess I will wait until I have the seat frame bent and covered before I make them. Today I cut the thick washers for the landing gear clamps and then started on the pushrods. I had cut the pushrod parts a while back but had to spend some time deburring and smoothing the tooling marks from the edges of all the parts. The smaller bare aluminium pieces fit inside the tubes and the plates go on the outsides to allow for bolting through the spherical bearings on the control arms. Hopefully I will get back and start flattening and drilling the ends of the tubes tonight. Shannon.