>>19682661st off, this is the wrong place to ask. It's a shot in the dark, to find someone w/ experience. Try one of the older forums.
2nd, I have some kind of background w/ brazing, and broadly I say "yes".
But there are so many Qs.
You mean a cargo bike w/ the frame extended to the rear or front? ('Big Dummy' vs 'Bakfiets'?)
Do you have any experience brazing?
You say 'torch', I assume an oxy + acetylene setup? Tubing from where? What braze alloys? (You won't hurt my feelings if it's not from Harris.) What's your fixturing like?
In a practical sense, that last question is the most important one.
This is the kind of thing I wish /n/ could talk about, but everyone here is fucking retarded.
You can get quite a lot done with simple fixtures, but there's not so much info online.
Do respond.