I have not been heating the tubes... But I have been thinking of doing so and I've also been considering making another crimper with a bigger pair of vise-grips. The Columbia I crimped before was easy, thin walled tubes I'm sure, as was the Rollfast I did. But this Schwinn is a new thing to me, tough, those stays gotta be thicker. After the work I've done so far, I've also came up with another way to drop the rear end. On the burrito I built, I lengthened the tubes right behind the bottom bracket, effectively swinging the rear axle up. But, I've got to figure out the fork first because that height will determine how far I want my rear axle to move up, and will I be able to save my kickstand? I feel a little woosey... Carl.