'This 65mm rule is totally stupid' - Newmen's 66mm deep rims are UCI compliant and can still be used in races

Newmen’s latest ‘Streem S.66’ wheelset, featuring a 66mm deep rear rim, has sparked debate following its use by Team TotalEnergies at Paris-Roubaix. Despite the UCI’s rim depth regulation capping maximum rim height at 65mm from January 2024, these wheels remain compliant due to a 1mm tolerance allowance for surface coatings such as paint and decals. This subtle margin, combined with adherence to overall wheel diameter limits, means the slightly deeper rims are still legal for competition, challenging the straightforward interpretation of the new rule. The UCI’s technical regulations specify that rim depth is measured perpendicularly from the outer to inner extremities of the rim, with a strict 65mm limit but a tolerance of one millimetre for coatings. Additionally, the overall wheel diameter, including tyre, must fall between 550mm and 700mm, indirectly limiting tyre sizes to around 38mm depending on rim width. This framework ensures wheels conform to safety and performance standards, but the tolerance has created a grey area exploited by manufacturers like Newmen to maintain aerodynamic advantages without breaching the rule. Newmen has openly criticised the 65mm rim depth restriction, describing it as “totally stupid.” A spokesperson explained that the regulation fails to account for inevitable manufacturing variances, particularly in carbon mould wear, which can cause slight deviations in rim depth. Newmen has adjusted its tooling to ensure rims measure no more than 66mm after painting, thus complying with the UCI’s tolerance. However, the company argues that the rule is overly simplistic, ignoring the aerodynamic interplay between rim and tyre, which varies significantly depending on tyre width and construction. The broader implication of this controversy highlights ongoing tensions between regulatory bodies and manufacturers striving for marginal gains in performance. While the UCI aims to enhance safety and control speeds through equipment restrictions, teams and brands continue to push boundaries within the rules’ technicalities. Newmen’s stance suggests a need for more holistic regulations that consider the wheel as a system rather than focusing solely on rim dimensions, potentially prompting future revisions or clarifications in cycling equipment standards.