Having researched tube bending companies on Google I compiled a list of likely candidates (about 7 in all) - the first of which was a company called Pipecraft based in West Sussex (http://www.pipecraft.co.uk/).
I spoke with a chap called Andy who was so helpful I didn't even bother phoning the other companies on my list!
Having discussed my requirements (and essentially because I am generally interested in all things engineering) we decided that it was probably best for me to pop down and visit Pipecraft with my tubing.
This enabled me to watch and learn about the process of forming the tube and also served as a splendid opportunity to get a proper feel for their manufacturing capability for use on future projects.
In the end Andy rolled my 4130 tubing on a ring roller, we experimented with both sand filled and empty tubing and it turned out the bend was so shallow sand was not required to support the tubing - see pics below:
|Andy in action on the ring roller!|
|Andy (with mesmerised Dad in background) demonstrating a tube mitreing belt sander.|
All in all an excellent visit, 5 shaped top tubes and lots learnt about tube bending, shaping and fabricating.
Everyone at Pipecraft couldn't have been more helpful and I couldn't have wished to work with a more open and generally welcoming group of people - contact them for all your tube shaping needs ;)