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, quietly rolled out this weekend.

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, which does have a tire width limit, there is not one for UCI road rules, at least not yet.

Instead, 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 precise follow-up check on the complete tire and wheel diameter.

One team source told Velo that on a standard wheel, tire width is effectively restricted to around 38mm to 39mm before the added sidewall height would start to push the limit.

Wider wheels have higher sidewalls, which could, in turn, push beyond the limit on the allowed total 700mm diameter.

The UCI found an easy workaround to what could have been a slow and tedious process of accurately checking each set of wheels on hundreds of bikes just minutes before the start of the race.

Monster tires pushing the limits
Pogačar rode monster 35mm tires at Paris-Roubaix. (Photo: Andrew Hood)

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 new tool is 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 was pushing even wider when fully inflated and barely slipped inside his front fork.

So far, no violations have been reported.