Why the UCI’s New 400mm Handlebar Rule Risks Doing More Harm Than Good

By Lee Prescott, President – International Bike Fitting Institute

The UCI’s recent announcement mandating a minimum handlebar width of 400mm for all competitive riders has sparked significant concern across the bike fitting and wider cycling communities. At the International Bike Fitting Institute (IBFI), we appreciate the intention behind the regulation—to discourage extreme equipment choices that may pose safety risks. However, in this case, a well-meaning rule could unintentionally compromise rider health, safety, and long-term participation in cycling.

Biomechanics Matter

As fitters, we know there is no such thing as a one-size-fits-all solution—especially when it comes to contact points like the handlebar. Biomechanically, most riders—particularly smaller-framed individuals, women, and juniors—naturally fall within the 360–380mm range for optimal bar width. Forcing them to use 400mm bars compromises shoulder alignment, increases strain, and degrades overall comfort and efficiency on the bike.

A Knock-On Effect for Safety and Control

To compensate for the mandated 400mm width, many riders are now rotating their lever hoods dramatically inward to achieve a narrower effective grip. This adaptation significantly reduces the rider’s ability to safely and confidently reach the brake levers from the drops—a critical control position, especially during high-speed descents or sprints.

Not only does this diminish safety, but it also puts riders in awkward wrist and hand positions that can lead to numbness, discomfort, and long-term injury.

The Industry Impact

Beyond the riders themselves, the regulation is already causing ripple effects in the cycling industry. Manufacturers—wary of regulatory constraints—are beginning to limit production of narrower handlebars. This could further reduce access to ergonomically appropriate equipment for the vast majority of everyday cyclists, not just professionals. The result? More riders on ill-fitting bikes, experiencing discomfort, and potentially walking away from the sport altogether.

We’ve Reached Out to the UCI

In light of these concerns, the IBFI has formally contacted the UCI requesting clarification on the reasoning and evidence base behind the 400mm minimum bar width rule. We have asked for a dialogue to explore alternatives that support safety and biomechanics. We are currently awaiting a response and hope to collaborate with the UCI to address this issue constructively.

Our Position

At the IBFI, we advocate for evidence-based, rider-first approaches to bike setup. Cycling should be a sport that welcomes all bodies, not one that inadvertently excludes them through rigid equipment rules.

We encourage our members, industry partners, and fellow fitters to share their thoughts and experiences. If you or your clients have been impacted by the new rule, we’d love to hear from you. Together, we can advocate for smarter, safer standards in cycling.

Lee PrescottPresident, International Bike Fitting Institute