Metal AM part failure sees Australian cycling team crash out of the Olympics
During the Tokyo 2020 Olympics, the failure of a metal additively manufactured bicycle handlebar caused the structure to snap while being ridden by Alex Porter, a member of the Australian cycling team (AusCycling), during his fourth lap in the men’s team pursuit challenge.
The resulting crash left Porter with friction burns and damage to his face, arms and legs. While the Australian team was permitted to ride again under a rule allowing second opportunities in case of mechanical failure, the team did not qualify in the top four, but, rather, placed fifth. This ranking meant AusCycling could no longer compete for the silver or gold medal in the event.
The failure occurred in the bike’s one-piece integrated base bar and stem, at the junction where the stem area transitions into the outward-facing base bar. The exact cause of the failure is unknown, but speculation in the metal Additive Manufacturing community on LinkedIn has been that the break was due to the type of brittle fracture which is a known risk in metal AM parts, which can have a lower ductile strength than forged materials.
However, an analysis of the fault in Cycling News by Josh Croxton suggests that the failure may have been caused by an over-torqued bolt, with the snap having occurred very close to the location of the base bar and stem’s frontal bolt hole.
The titanium part was produced by Bastion Cycles, Fairfield, Australia. In a statement issued by the company, a Bastion spokesperson said, “The team at Bastion Cycles is working with the Australian Olympic team to understand the cause behind the failure of one of its handlebar units during the four-person, Australian pursuit challenge at the Tokyo Olympics.”
AusCycling has announced a full investigation into the incident.
