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Why won't the UCI allow disc brakes on the road?

Paul Lew, the man behind Reynolds wheels, asks why cycle sport's world governing body is resisting change

Paul Lew, the man behind the Reynolds range of wheels, has been nominated as the Vice Chairman on Wheel Committee after two years on the board. The committee is a sub-group of the Bicycle Technical Committee and deals with UCI on the issue of wheels.

Why would you care? Well, the committee has an ongoing conversation with the UCI on the approval of wheels for UCI-sanctioned events.

Currently, the UCI requires rupture testing of all “non-standard” wheels which have “rims taller than 2.5cm, fewer than 16 spokes and spoke thicknesses of over 2.4 mm". Here’s the current list. The UCI aims to ensure wheels are safe for racing, while the manufacturers say the UCI testing protocol is unrealistic and hard to reproduce.

The committee met most recently just before the Eurobike show, with a discussion about disc brakes. The UCI don't currently allow disc brakes in road events. Paul Lew has provided his observations coming out of that meeting. We'll print them in full...


"The day before Eurobike started, I participated in the most recent UCI disc brake discussion. In that meeting, compelling evidence was presented that indicates the UCI may postpone its approval of disc brakes indefinitely. With most of the industry’s key suppliers embracing the new technology, one might ask: “Why is UCI resisting the technology of road disc brakes?”

For some insight as to why the UCI is resisting the technology of road disc brakes, here is an excerpt from its presentation. Please excuse any typos, misspellings, or grammatical errors — these are the words, spellings and phrases from the UCI’s 27 August 2013 presentation (everything that follows in bold italics comes from that presentation).


1 Disc brakes are still considered as technical innovations on the road and have to be submitted to the UCI and approved by the Equipment Commission to be allowed in competition after one or several test events.

Until today no disc brakes adapted for the road cycling was never presented to the UCI. 

3 Challenges on the road are very different from the mountain bike or cx with

• Higher speed

• Longer braking time

• Higher temperature accumulation

• Bigger disk which means bigger issue in case of crashes

• Braking behaviour that may block the wheel and make the bike slip

• Difference of braking performance between disk brakes and rim brakes that may cause crashes inside the peloton

The UCI don’t want to allow dangerous, non-adapted braking systems in competition that may cause even more crashes instead of improving safety

If disc brakes will be allowed on road events, enough time will be given to the industry to adapt to this decision


For cyclists who compete in UCI-sanctioned events or sanctioned events that adhere to UCI regulations, the message is clear: disc brakes are not allowed. UCI has made it clear that they have reasons not to accept disc brakes and if we take a historical perspective, UCI is not easily persuaded to adopt regulations that permit new equipment.

For cyclists who don’t compete in UCI events, it’s easier - and also a bit more complicated. Disc brakes are here to stay and they offer many benefits. Certainly, they are “allowed” for casual group riding and tours. Those who intend to compete on bicycles with disc brakes in local events will need to check regulations on a case-by-case basis. 

The UCI attitude regarding disc brakes will influence the trajectory of disc brake technology, which is driven by the willingness of manufacturers to invest in developing and advancing disc brakes, and the consumers’ demand for purchasing them.

Reynolds Cycling has made commitments to embrace the new disc brake technology, and to simultaneously improve our rim brake technology. For example, in 2013, Reynolds has released both an upgraded rim braking system (the Cryo Blue Power brake pads), as well as its first disc brake road wheel, the Assault Disc. As one of the early adopters, Reynolds Cycling will invest a significant portion of their product development budget to lead the market place with innovative disc brake wheels and solutions.

Time will tell where the UCI goes with approving disc brakes on the road. Reynolds and I will remain committed to participating in the discussion, ensuring safety, and embracing innovation. Whatever the outcome, the cyclist and the sport are always better off for having new technology options."


So, according to Paul Lew, the UCI isn't in any great hurry to allow disc brakes in competition on the road, and it might never actually approve them.

Now, it must be said that these comments were made prior to today's election of Brian Cookson to the UCI presidency. Our next question to Paul Lew is whether he thinks the new change at the top is going to make a difference on this issue. We'll keep you posted.

Taking that a step further, will the new regime be changing other equipment rules any time soon? The best known rule, of course, is that complete road bikes aren't allowed to weigh any less than 6.8kg, but many maufacturers we speak to feel that other restrictions currently in place are also limiting the progress of bicycle design. 

Wouldn't now be a good time for a wholesale review of the rules and regs?

Post script

We now have a reply from Paul Lew. Here's what he says...

"It's important to know that neither I, nor anyone else [on the committee], had any input [on UCI's position] - this was a word-for-word recap of UCI's position at that moment. That's not to say that in the future I and other committee members won't have input.

"In my position as a representative of manufacturers and cyclists, as well as a fair-minded ambassador for UCI, it is important that I stay balanced in my perspective. This means that people who have an opinion for or against disc brakes may from time-to-time find frustration with my opinion on the matter, which is to try to walk a narrow line, halfway between welcoming innovation while also working to see the UCI perspective.

"This IS a negotiation and taking a hard position from either side will stall progress. It is my job to try to find an agreeable way to encourage innovation while respecting the traditional attitudes of UCI. There is a gap and we must build a bridge, not stand on one side of the gap or the other and sling arrows."

The issue of disc brake use in road competition looks set to be a big topic of debate for the forseeable future. Whatever the eventual outcome, it surely needs to be addressed properly with serious examination of the facts, because right now nobody really knows how it would influence road racing or whether oft cited safety concerns are well-founded.

David worked on the tech team from 2012-2020. Previously he was editor of and before that staff writer at RCUK. He's a seasoned cyclist of all disciplines, from road to mountain biking, touring to cyclo-cross, he only wishes he had time to ride them all. He's mildly competitive, though he'll never admit it, and is a frequent road racer but is too lazy to do really well. He currently resides in the Cotswolds, and you can now find him over on his own YouTube channel David Arthur - Just Ride Bikes

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