I am going to build a custom swingarm in my shop at school i was wondering what type of metal to use. I was thinking round stock alluminum but it could bend easy. I am going to use it for silver lake sand dunes in michigan and i have a track with a 62 foot table top that shoots me about 15-20 feet in the air. That should give you an idea of what type of metal to use. I need it to be lightweight.