Tire width was the buzz at Paris-Roubaix: UCI checked this instead

The buzz in the Paris-Roubaix paddock on Sunday was all about the super-wide tires that Tadej Pogačar and others were racing on.

Teams rolled out meaty 35mm tires to ease the pain on the most brutal race of the year.

But the UCI tech police weren’t checking that, at least not directly.

Velo spotted UCI commissaires doing their typical pre-race bike checks, including magnetic scans of wheels and frames to detect motors (none found) as well as measuring handlebar width and positioning.

The UCI staff also deployed a small 3D-printed measuring tool. Bike Radar reported that the device is not yet listed on the UCI website.

They weren’t measuring tire width. They were measuring tire height.

A commissaire told Velo on Sunday that they were not checking tire width because, unlike cyclocross, there is no width limit under UCI road rules, at least not yet.

There are rules about wheel diameter, and that’s what the UCI was checking on Sunday.

The official told Velo they were using the fitted chunk of plastic to indirectly check for wheel diameter compliance, limited to 700mm, including the full wheel and tire setup.

The UCI reversed-engineered its gizmo to slip over the top of the tire.

If the sidewall height was near the limit, officials could then do a more precise check on the complete tire and wheel diameter.

One team source told Velo there could a ceiling on how wide tires can go. Ever wider tires would have higher sidewalls, which could, in turn, push the whole setup beyond the limit.

Monster tires pushing the limits

Teams have been aware of new rules since the beginning of this season, and were cautious not to be caught out by surprise just minutes before the start of Paris-Roubaix on Sunday.

The gizmo is part of the UCI enforcement toolbox.

On Sunday, commissaires also used the tool to measure inward angles of brake lever hoods, first rolled out in 2024.

It’s part of the ever-evolving UCI arsenal to enforce rules compliance at races, a sometimes contentious tug-of-war between teams and suppliers on one side and the UCI’s rules on the other.

Visma-Lease a Bike, for example, was notified just weeks ago that it could not race with its tire pressure regulator on Sunday.

Wout van Aert raced without it and still won his emotional victory despite puncturing twice during the race.

There was plenty of chatter about riders rolling out new super-wide tires for the Hell of the North.

Velo spotted at least three teams with 35mm tire width on Sunday. Tadej Pogacar’s 35mm tire width when fully inflated barely slipped inside his front fork.

So far, no violations have been reported.