This is helpful, thanks. I managed to find a fairly cheap Aluminum square tubing on the Home Depot website which had similar dimensions. I'll keep this thread updated on the progress, and hopefully receive more help that will most likely be needed.
Okay, so I'm new to this forum, but I'm hoping I can get some help. I live in the United States, and I'm having trouble converting from metric to standard with the build plans given. I want to build the open source Spaceframe recumbent bike which the build plans can be found...