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UCI Gives Update on Hookless Rims with Tubeless Tires Ahead of Paris Roubaix

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Just as the cycling world is preparing for one of the biggest single-day races of the season, the UCI has announced its first guidelines on the subject of hookless rims with tubeless tires. The announcement is fairly brief, and breaks down their plans for the “short, medium, and long term.”

Essentially, for now they just recommend teams and riders to follow the ISO standards 5775-2:2021 and 5775-1:2023. These standards ” provide a framework for the compatibility of tire and rim widths on bicycles.” Stating that these standards have not always been respected, the UCI points out that adherence has been made more difficult since the European Tyre and Rim Technical Organisation (ETRTO) standards have not always aligned with the ISO standards.

Looking ahead, it’s clear that the UCI hopes to work with all parties to come up with a more concrete solution, but for now, all they can do is recommend that tires and rims are within spec.

From UCI:

Following its statement on recent incidents involving the use of hookless rims with tubeless tyres, the Union Cycliste Internationale (UCI) is today in a position to issue its first guidelines on the subject for the short, medium, and long term. 

The UCI’s initial statement came in light of several incidents that have occurred in professional road cycling over the last two years at events on the UCI International Calendar, including this year at two UCI WorldTour events – the UAE Tour and the Strade Bianche (ITA) –, as well as concerns expressed by road cycling stakeholders about rider safety.

In the short term, the UCI reminds teams and riders of the requirement set out in article 1.3.018 of the UCI Regulations, which imposes compliance with International Organisation for Standardisation (ISO) standards 5775-2:2021 and 5775-1:2023 in cycling competitions. These standards provide a framework for the compatibility of tyre and rim widths on bicycles. The UCI notes that the norms defined in these ISO standards have not always been respected and does not rule out the possibility that this may have been a contributing factor in some of the incidents encountered.

The UCI also recognises that compliance with the ISO standards by teams and riders is made more difficult by the fact that manufacturers base their recommendations for compatibility between tyres and rims on the recommendations provided by the European Tyre and Rim Technical Organisation (ETRTO), which have not always been aligned with ISO standards.

Further information on articles 1.3.018 and 1.3.002 of the UCI Regulations, which both refer to the ISO standards mentioned, is available in the UCI Technical Regulations Clarification Guide.

In the medium term, the UCI has taken the decision to mandate SafeR – the newly formed entity dedicated to safety that brings together all stakeholders of professional road cycling – to work with all parties concerned, including teams, riders and the cycling industry, to explore potential improvements and clarifications regarding the use of hookless rims with tubeless tyres that would be relevant to incorporate into the UCI Regulations. SafeR will provide their recommendations, to be considered for application for the 2025 season, in a report with the aim of continuously improving rider safety. In particular, teams, riders and Commissaires are asked to report any incident involving hookless rims with tubeless tyres that may occur and to ensure that the circumstances of the incident can be analysed in detail.

In the longer term, the UCI will carry out an in-depth analysis of the appropriateness of the current requirements for the use of different types of equipment in competition, in particular wheels, to ensure that these requirements guarantee the safety of riders, are adapted to professional cycling, and do not rely exclusively or for the most part on the diligence and internal processes of manufacturers.

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Glenn
Glenn
6 months ago

The UCI says..”are asked to report any incident involving hookless rims with tubeless tyres..” but if only incidents from hookless rims are reported, how will an adequate and unbiased comparison be made with hooked rims, tubed clinchers, or tubeless tires?

Helpful Jeff
Helpful Jeff
6 months ago
Reply to  Glenn

There’s none so don’t worry about it

Antoine Martin
Antoine Martin
6 months ago
Reply to  Helpful Jeff

Bullshit, i’ve had a tire jump from a hooked rim and none from my hookless. I’m not even saying i prefere hooked or hookles, i mostly don’t care but it’s way more complicated than some would like this to be. It’s not “no hook bad hook good”. In motorsport most rims are hookless and tire sustain ridiculous loads.

Thetruthhooks
Thetruthhooks
6 months ago
Reply to  Antoine Martin

Motorsports are an incredibly poor analogy. Tires have wire beads and are such a close fit they require hydraulic presses or long crow bars. Nothing about tire or rim construction in Motorsports is relevant to the conversation. Bike tires have completely different casing construction, and are loose enough that thumbs or a small lever are sufficient to install. Motorsports tires are also subject to government regulation and testing standards. Bike tires are hypothetically built to standards, as are rims, but they’re effectively a toy and built to standards not much more stringent.

Helpful Jeff
Helpful Jeff
6 months ago
Reply to  Antoine Martin

@UCI valuable data alert!

Rim Brake enjoyer
Rim Brake enjoyer
6 months ago
Reply to  Antoine Martin

Today in “guy who has never mounted a motorcycle or car tire in in his life”

Matt
Matt
6 months ago

If I may speculate, I do wonder whether stretching of the tire bead by brute-force installation plays a role in hookless blowouts. Food for thought: Maxxis tire instructions say to mount them without using tools, and I did wind up with a stretched-out tire once when I mounted one using a tire lever–it wobbled right where I had used the lever. That Minion DHF stayed seated, but I (1) was running it on the correct width of rim, (2) was using a hooked rim, and (3) was running it in the 20’s of PSI.

Nate
Nate
6 months ago
Reply to  Matt

What blow outs?

SomeGuy
SomeGuy
6 months ago

I’m so over this. The recent failures were not hookless blow-offs. THE.RIM.WAS.BROKEN.

Carbon rims break when they hit something hard enough and when that happens with a tubeless system, the tire deflates. Deflated clincher tires are unlikely to stay on the rim. Doesn’t matter if there’s a tube, no tube, what the tire was made of, what you filled it with, whether it was air, nitrogen, helium, or kitten flatulence. Rim breaks, air goes away, tire comes off the rim.

Focusing on the hookless element does not solve anything here. If a bunch of houses built by the same contractor are burning down, we might have some questions, but we’d probably start with looking for an ignition source. What we wouldn’t do is blame the plumbing.

Learn cause and effect before you just blame the new thing.

Alex
Alex
6 months ago
Reply to  SomeGuy

A tubular is more likely to hold onto the rim due to the glue. A hooked clincher will hang on better than a hookless, but that depends on how big the break in the rim is. If it’s a small break, the tire bead should hang on longer.

SomeGuy
SomeGuy
6 months ago
Reply to  Alex

Tubulars can stay in place when they flat or if the rim breaks because they’re glued on, but that is a completely separate conversation.

These were not “small breaks”. In one of these photos, we can see that the rim was cracked all the way through and even dislocated. A clincher bead is held in place by air pressure and the firm structure of the rim. When a tubeless rim breaks in this way, the pneumatic seal is lost and the air pressure goes away. Hooks can help retain a tire *at higher air pressures*, but the physics change for a tire with no air in it.

Hooks need air pressure in order to even become a factor, so they don’t solve any problems related to this type of failure. Without air pressure, the bead can pull away from the inner rim wall – and the bead hook, if there is one – dropping into the center channel where the rim diameter is smaller. This loosens the tire fit – all with weight of the rider still on the bike. We can see De Ghent’s wheel turn sideways as well while this is all happening. It would have been far more surprising if the tire had stayed on.

Robin
Robin
6 months ago
Reply to  SomeGuy

And tubular tires sometimes come off when a rim breaks. When a wheel breaks as badly as the one in question did, all bets are off no matter the tire.

Andreas
Andreas
6 months ago

I actually support UCI here. Working to align standards, and potentially sharpen up the dimensional requirements would be good for the sport, and act as an enabler to progress. Then, if combining products that follow such standards is done, the current hit and miss with different rims and tires being loose or near impossible to fit on the rim would be reduced, and that would make it easier for everyone. As these things take time, I wouldn’t hold my breath though.

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