Re: Frame material questions
The main problem I see is not the material as the way you have to set the frame up or "tack" or "pin" it so that you get the correct angles and spacing. The book I got a few years ago was "the Pateriek Manual for frame builders". It show the complete steps from a to z on building a bike frame.
As for My motor bicycle I started with a old Giant mountain bike frame and swapped the rear dropouts and changed the fork length ect, to get to the point were I was happy with the handling and placement of the wheels ect. I started by going to the local used bike place in Portland OR. The place is called "City Bikes" and for about forty bucks I had a strait frame to start with. The least amount you can pick up a set of frame tubes from a place like NOVA is about a hundred and fifty bucks and then your still not really set up to build a frame.
The first bicycle frame I put together I did not do a very good job, but if you have the skills of a good welder than the most thing you have to deal with is the design of the frame. Its not super easy job to set up. I have a little program on my Iphone called "Size My Bike" and I am hoping it will get me a starting point for my next frame I will be putting together.
there it a show on the Discovery Channel called "Cafe Racer TV" and they always start with a old motor cycle frame and then modify it to make it work for their needs. I have yet on that show to see them start fresh with just a set of tubes.
For me I like steel because its very reliable I can guess when its going to get in trouble and can modify my design to suite.
I like the stout CRMO tubing that my bike is made out of and on these kind of bikes I like to overbuild just for safety sake.
the first frame I put together I made my own jig out of square one inch tubing and it did OK because all I did was to hold the steer the seat tube and the rear dropouts in alinement but my new jig holds all of the tubes right were they need to be.
the first frame I put together was a set of TANGE Number three strait gage tubing with Columbus lugs and it took me about a week to get it right and even then I was not totally happy with the way it came out. Well its been about five or ten frames since then(including repairs) and I feel a little more confident now.
as for material I say go with steel its been working for over a hundred years and it seems to do the job for me.