Rui Costa's chainring failure at the Tour de Romandie prologue earlier in the week was down to the use of incorrect chainring bolts, not an equipment failure, Cyclingnews can report.
Lori Barrett, the Managing Director of the team's chainset supplier, Rotor, contacted Cyclingnews to share information and an update from the Intermarché-Circus-Wanty team on the mechanical issue.
"Rui ripped out all four of his chainring bolts when putting on high load when leaving in big gear from the start podium. The mechanics found all 4 broken bolts on the start podium," read a message between the Intermarché-Circus-Wanty DS and Barrett.
It continued: "I immediately requested pictures from them and there I noticed a mistake. They used by accident the short chainring bolt for single chairing [sic] versus the standard one for double chainring. So the big chainring was not fully supported by the nut. The two versions of the bolt are next to each other in [the] service course, so human mistake there. We have instructed all mechanics to check all bikes and made them aware of the two different types."
It transpires that Costa was using a double chainset, but with the shorter chainring bolts designed for single chainrings fitted in error. The shorter bolts would have had minimal thread engagement which wouldn't have held up to Costa's starting effort, resulting in the bolt failure.
Cyclingnews has reached out to the team for comment but hasn't received a response at this time. We will update this story if we receive further clarification.
