To accommodate plump tires and fenders l put a large bend in 22.2 ROR chainstays ( https://www.flickr.com/photos/216244...in/dateposted/ ). I use a home-made bending mandrel ( https://www.flickr.com/photos/216244...in/dateposted/ ) and for bending support have filled the stays with wax, a wax/sand mixture and with sand only; with the latter, one end is capped, the other has a nut brazed on and a bolt providing compression which I increase as I go, bit by bit. I've have had reasonable, if not 100% success with those methods, and I can't help wondering if Cerrobend or Wood's Metal would improve the results. Anybody here have direct experience to share? Given the chemistry of the alloys I'm particularly interested in how one works with these materials safely in a shop environment.