Frame tube thickness/ crank length

Hi everyone, i have some questions to ask.
First of all does anyone know how thick frame material is?
Second, what size do you run on your 24" muni and why that size and not another?
and my final question is for andrew carter, what did the material required to build your frame cost and what sort of metal is it made out of, steel, chromoly or smething else?
thanks for all responses

Sorry for the late reply and for bringing up an old thread. Here are a few answers, bearing in mind that I’m the the best person to be asking and have no metalworking experience.

Tubing thickness - The tubing I’ve used is called ‘streamline’ and has a sort of tear-drop shaped cross-section. This is very similar to what I’ve used - . The second on the list is much the same as mine (approx. 30x12mm, 0.9mm thick). Since my framebuilder and I are trying to experiment with lightweight frames and the minimum requirements, I think 0.9mm is probably the thinnest you’d want to go for a muni or trials frame.

Crank size - I’m running 160mm cranks. I love them. I used to ride with 140’s but didn’t get enough torque out of them, and I feel that 165’s and especially 170’s are too awkward for me and have more chance of hitting the ground. Here in Queensland we have lots of rocks, ruts, and other miscellaneous bits and pieces to hit the pedals on, as you know. Having said that, Kris Holm rides with 165’s, as far as I know, and he’s the one you should be looking to for guidance. I’m really glad to see that he’s broken free from that 170mm standard size in his products. I run 160mm Profile cranks on my 24" muni.

Material costs - I can’t remember exactly, but I think the materials alone (streamline tubing, and the round neck of the frame) cost about $80. I got the bearing holders free from Gary at though, which was nice. Apparently this tubing was comparatively expensive though. It is 4130 chromoly as far as I know.

Good luck! Do you have a project lined up?