Nice research work on bike frame design from Des Covill as reported in Cycling weekly (http://www.cyclingweekly.co.uk/news/latest-news/new-research-unlocks-secrets-of-steel-tubing-189907). The full papers are here . . . http://www.sciencedirect.com/science/article/pii/S1877705815014216  and
http://www.sciencedirect.com/science/article/pii/S1877705814005931