Would dropping the UCI weight limit put an end to disc brake bikes in professional races?

We ponder if dropping the UCI weight limit will cause more problems than it solves for disc brake evolutionists

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The UCI weight limit, or ‘Technical Regulation 12, Article 1.3.019’ is a rule in professional cycling that stipulates “the minimum weight of the bicycle (in working order) is 6.800kg, considered without on board accessories in place.”

First introduced in 2000, the 6.8kg rule was originally intended to ensure rider safety at a time when there was considerable unease about carbon-fibre and the prospect of manufacturers pushing the limits of the material.

Since then, technology has improved, meaning that sub 6.8kg bikes are common. To hit the weight limit on pro bikes, mechanics sometimes have to add weight, usually lead weights down the seat tube, or manufacturers apply extra paint.

>>> Should the UCI weight limit be scrapped?

With the steady improvement of carbon-fibre technology many feel the 6.8kg rule is no longer relevant and this has led to pressure on the UCI to drop it.

When asked for comment the UCI responded: “We would like to review this rule and are in consultation with stakeholders including teams and the industry, to bring it up to date.”

If the rule is scrapped or lowered will it kill off disc brake bikes in the pro peloton for good?

Juergen Falke, director of products at Merida believes it could: “Because disc brake bikes require a reinforced fork and frame, thru-axles, disc-rotors and hydraulic reservoirs the weight penalty over a comparable rim-brake bike will be at least 500g with the coming disc brake generation.

“At the moment it is more like 650g or more.”

What the pros think about disc brakes

Development decrease

CEO of Edco and industry expert Paul Lew suggests it could slow the overall development of disc brake technology too: “If a decision were to be made soon, and the 6.8kg rule goes away, then it probably discourages further disc brake work and development.

“I wouldn’t say it ends it, but it does discourage it. Who wants to ride disc brakes if the 6.8kg rule goes away and everyone is able to ride 5.8kg bikes?”

James Shaw recently signed for Lotto-Soudal having previously ridden for its under-23 team.

When asked which option he would choose, a sub 6.8kg road bike, or substantially heavier disc-equipped machine, he admitted: “I’ve not ridden road discs yet, but I would be inclined to go for the lighter bike.”

This may present a problem for those marketing disc brake bikes by having professionals ride them.

>>> Disc brakes in the WorldTour: are they necessary on road bikes?

Falke works closely with Merida-sponsored teams and warned: “Most racers would vote some weight saving over improved braking, because all pros are crazy about weight.”

In Lew’s opinion, “The UCI won’t make a decision on the 6.8kg rule until disc brakes have been accepted or declined by professional racing.

“Taking away the 6.8kg rule could have significant effect on disc brake acceptance. In my opinion, disc brakes have enough obstacles on their own without another distraction.”

>>> Disc brakes: everything you need to know

Shaw does believe the pro peloton is open-minded towards discs though, stating: “As much as pro riders look for a weight gain or aerodynamic gain, they would also take a braking gain.

“[But]one thing we can’t have is some guys on discs and others not on discs. It wouldn’t be safe with some braking later into corners.”

Our take

Considering how much effort and sacrifice the world’s best climbers go through in order to lose a couple of kilos of body weight, it is likely that a disc brake bike weighing 7kg will not be an attractive proposition if they also have the option of a 5kg machine.

Trials of discs in the pro peloton will be resumed in 2017, but the future of them remains very much in the balance.

Eight things to know

Expert view

Juergen Falke, Director of products, Merida R&D

“The reality in road racing at WorldTour level is that very few bikes in the peloton fall below the 6.8kg limit.

“In most cases, pros don’t use the ultimate lightweight version of the frames: teams mostly use either the second material level or special lay-ups with a focus on maximum stiffness and high robustness.

“Tyres have 25mm width with a focus on puncture resistance and maximum grip. Stems and handlebars are also selected according to stiffness and robustness, not with a focus on lowest weight.

“Considering all this, even a drop of the UCI bike weight limit ‘just’ down to 6.0kg just increases the expense of ‘tuning’ material up and does not create more fairness.

“With regards to discs, the whole industry wants to see pro racers use disc brakes.

The whole Fran Ventoso story and subsequent ban of disc brakes in April 2016 — and the way the different, involved parties acted was simply not professional at all and was far from objective.

“There is no doubt that disc brakes are better and offer a higher level of safety for a rider and his opponents due to more predictable braking under all kinds of conditions.”