While Bora-Hansgrohe's Wilco Kelderman blamed disc brakes in part for losing 10 minutes on stage 9 of the Giro d'Italia, his bike and wheel sponsors, Specialized and Roval, denied his claim.

Kelderman finished 33rd, losing 10:53 on the Brockhaus climb, but was already on the back foot before the hill began. One of the losses was due to a broken spoke, he said.

After the stage, an exasperated Kelderman claimed that the broken spoke was due to heat from the disc brakes.

"On the last climb down, a spoke broke off the wheel. I think the disc brakes got very hot and the spoke got warm," Kelderman explained to Dutch outlet AD (opens in new tab). 'It was a very fast downhill, so the pressure broke the spokes.'

Kelderman's bike is equipped with Shimano Dura-Ace R9200 series disc brakes, and the spokes in question are Alpinist from Roval, a subsidiary brand of Specialized that also supplies bikes, helmets, and shoes for Bora Hansgrohe It is part of the CLX II wheelset.

In response to complaints, a Roval spokesperson denied the claims.

"We are in close contact with the team, but it appears that a spoke broke during a major impact and the wheel had to be replaced," Roval category leader Chris Wehan told Cycling News. The broken spoke was on the drive side; heat from the brakes was not the issue and had nothing to do with it."

"The team confirmed he hit something," reiterated Kelly Henningsen, Specialized's global PR and media relations leader.

According to Wehan, the spokes broke because they were intentionally designed to deflect the force of the impact away from the rim and toward the hub.

"We design the wheel as a complete system so that when the rider is subjected to a significant impact, the forces are transferred from the tire/rim pressure vessel through the rim to the spoke bed and spokes. This ensures the structural integrity of the wheel system and allows the rider to stop completely and safely for a wheel change.

The wheels used by Kelderman were only announced by Loval a week ago, but the team has been using these and deeper Rapide CLX II wheels since the start of the season.

The launch of the new wheels marks a return to tubeless for the Roval and Specialized brands, which were forced to return to square one in 2020.

A few months before the original Rapide CLX and Alpinist CLX were scheduled to be released, Peter Sagan, then with Bora-Hansgrohe, damaged a wheel during training and the tire self-removed.

Even though the wheel had already passed the necessary safety tests, Roval and Specialized decided that it was undesirable to take the risk that this could happen to a consumer, and instead took the surprising step of selling the wheel as "inner tube only. This was a surprising move.

After a redesign that supposedly included the aforementioned impact force deflection, Roval is now confident that the second iteration can be used safely.

Stage 9 was ultimately won by Kelderman's teammate Jai Hindley. He used the exact same bike, groupset, and wheelsetup as the Dutchman.