The UCI weight limit rule, which says bikes used in competition must weigh a minimum of 6.8kg, was intended to ensure rider safety. But, in practice, it disproportionately affects smaller riders, particularly women.
I don’t know the official origin of the UCI weight limit, but my theory is the men’s peloton was the reference point when the rule was set in 2000.
Back then, I’d guess the average weight of a male professional cyclist was around 68kg, and someone decided the bike should weigh roughly 10 per cent of that, which is how a minimum weight of 6.8kg was decided. Perhaps there was a little more analysis behind it, but the principle seems that simple.
The problem is that this thinking is completely outdated. The rule has been in place for the entirety of my professional career, which spans over 18 years.
Since then, the bike industry has evolved dramatically, constantly pushing boundaries and innovating, yet the UCI’s rules and mindset haven’t kept pace. For someone like me, with an engineering background, that contradiction is especially frustrating.
Take a climb such as the Col de la Madeleine, which featured in this year’s Tour de France avec Zwift, and is 18km at 8 per cent. As I explained in a LinkedIn post, a 52kg rider putting out 5.5W/kg will climb it at about 14.3kph.
A 60kg rider with the same relative power climbs at 14.8kph, which means they’ll be 1 minute and 16 seconds faster on the climb. This is because the fixed bike mass is a smaller portion of their total weight, so the power-to-weight ratio of the heavier rider’s complete setup is higher.
A hand pulling me backwards
The UCI weight limit was particularly frustrating early in my career, before disc brakes became the norm, and most of my race bikes were well under the 6.8kg limit.
- Read more: Road bike disc brakes: everything you need to know about road cycling's most controversial tech
I spent much of my career on Cervélo, and the R5 in my size was typically 6.2 to 6.3kg. The only way to meet the regulation was to add ballast, which the UCI mandates must be hidden from view.
In practice, this almost always meant putting the weight down the seat tube so it sat near the bottom bracket, which was thought to be the safest place for handling. But bikes aren’t designed to carry extra mass there, and it completely changed the ride dynamics.
As a small climber who spends a lot of time out of the saddle, the added weight at the bottom bracket shifted rearwards whenever I stood up. It felt as though someone had a hand hooked into my back pocket, pulling me backwards – a sensation that genuinely affected my performance.
Challenging the UCI
As my results and standing in the peloton had grown, I felt I had the authority to raise the issue of the minimum bike weight directly with the UCI. In 2019, I was riding for CCC-LIV on the LIV Langma with Cadex wheels, another bike weighing around 6.2kg in my size. The weight penalty was substantial, and I was vocal about how it impacted my racing.
The UCI’s response at the time was telling: it agreed the rule was outdated and should be changed, but said I shouldn’t expect it to happen anytime soon. That has essentially been the only answer I’ve ever had.
Once disc brakes became standard, the debate over the UCI weight limit faded, because it’s rare for a disc-brake bike to be under 6.8kg. But the industry keeps innovating, and now we’re back where we started.
I currently ride for WorldTour team AG Insurance–Soudal, which uses bikes from Specialized.
The Specialized S-Works Aethos in my size (48–49cm) with disc brakes weighs around 6.2kg straight out of the box. It’s a perfectly safe bike – Specialized sells it to the general public – and it would be a huge asset for me on major mountain stages.
Yet I can’t race it purely because of an outdated, one-size-fits-all rule designed around the physiology of the average male pro.
Below the design norm
As a light rider, I’m far more sensitive to stiffness profiles, bike weight, and even wheel handling, than the average rider.
That sensitivity comes down to two things. Firstly, we’re below the ‘design norm’. A lot of equipment is designed around average-sized riders, so smaller sizes are often just scaled down without rethinking stiffness or handling characteristics. This can make bikes or wheels disproportionately stiff or harder to accelerate.
We also lack momentum. Whether it’s bike mass or wheel depth, we don’t carry the same inertia as bigger riders – and that affects how the bike responds.
A good example is wheel choice. I will almost always choose lower-profile wheels, even though high-profile wheels are lighter than ever and supposedly offer big aerodynamic advantages.
For me, deeper wheels feel harder to accelerate – the stiffness and rotational inertia make them slower to get up to speed. Once you’re at high speed, the aero benefit is great, but you have to get there first. So, even on flat stages, I often prefer low-profile wheels for their responsiveness and explosiveness.
In recent years, I’ve had the privilege of being a team leader, which has given me a lot of say over my bike setup. But that’s not the case for everyone. Domestiques or riders lower in the hierarchy often have less choice, even if their equipment is a poor match for their physiology.
I know of riders on strong women’s teams, whose smallest-size race bikes are actually heavier than the 6.8kg limit, which is a huge disadvantage. And they have no power to change that.
This all ties back to something I’ve often said: in professional cycling, salary is only one part of the decision when choosing a team. The environment and the equipment matter enormously, particularly for smaller riders.
Your bike should feel like an extension of your body
Ideally, your bike should feel like an extension of your body. If it’s too stiff, it resists the natural movement and rhythm you have when climbing, especially out of the saddle. That resistance costs energy and reduces efficiency over a long climb.
These are the main reasons why smaller riders – often without even consciously breaking it down – will tend to choose climbing bikes and lower-profile wheels on mountain stages. They might just say, “This setup feels better for me”. But what’s really behind that preference is a combination of stiffness, handling and the ability to accelerate the bike with lower absolute body weight.
In my experience and calculations, the real 'sensitivity threshold' to these factors starts at around 56kg. Above 60kg, the relative effects of bike weight and wheel inertia become far less significant. For riders under that, the impact is very real. And in many cases, it’s career-defining.
