Challenge Tyres has issued a consumer safety bulletin to customers, confirming that its tyres should not be used with any rims or wheels that do not comply with either current 2019 ETRTO, past ETRTO or soon to be released ISO 5775 global standards for tyres and wheel fit.
Challenge said in the statement that it has noted multiple failures of its clincher tyres by both consumers and sponsored teams caused by sharp edges on the ENVE SES hooks:
“Challenge has therefore been forced to list the ENVE SES rims as not compatible with our clinchers models on our website. We ask that consumers do not mount ENVE SES wheels with any model Challenge clincher tires, handmade or vulcanized, standard clincher or tubeless ready, made from our lowest level nylon and butyl construction through our highest quality tire production made with polyester, cotton or silk casings and latex construction.”
Failure to follow this warning could cause the ENVE SES wheel to cut Challenge’s casings, resulting in explosive air loss from the tire and/or inner tube, potentially causing a crash and injury to the rider.
Challenge clarified in the statement that both old and new ETRTO and future ISO standards require a minimum 0.7mm radius on all hooked rims. According to the brand, it came to attention that ENVE SES model carbon wheels do not comply with any of the above standards on the design of the hooked rim radius.
The design standard violation has been clearly communicated to affected consumers, shops, sponsored teams, ENVE and its parent company as Challenge has been made aware of problems.
Challenge asks that consumers do not mount ENVE SES wheels with any model of Challenge clincher tire whatsoever.
Here is the Full Consumer Product Safety Bulletin and advice for Challenge customers.
If you have any questions please contact Challenge directly at firstname.lastname@example.org.