When I started building bikes, there was some plumbing work to be done in my house and my old 25 year old cheap gas burner was more or less dead, so I invested in a Rothenberger super fire2 torch and map gas, it's a bit warmer than a normal soldering torch.
I also use the burner to bend tubes for my bike projects and it works ok up to 25mm x 1.6mm, I have done 40mm x 1.6mm , it worked for a light bend, see last picture below, but needed more heat, next time i will borrow a second map gas burner.
The method is to fill your tube with kiln dry sand and cap the ends, then heat the tube as much as you can. Then slowly bend the tube around your jig, moving the heat forward as you bend.
The advantage is that you have full control of the shape of bends. But it take some trials to keep the heat constant.
The bend around the wheel could have been better, first time doing a 180deg bend.