Pro cyclists often appear to ride bikes that are disproportionately small for them. But why?
No, it’s not just a trend… and it’s not quite just “marginal gains,” either. For the pros, bike sizing is actually important for strategy.
Do you want to learn more about why pro cyclists ride such small bikes? Let’s take a quick look at some of their reasons… and even explore whether it’s a good idea for amateurs to emulate them.
A few big reasons for all the small bikes.
Have you ever noticed while watching the Tour de France or another major bike race that some of the pros’ bikes look kind of… tiny?
Okay, they’re not so small that they look clownish. They’re definitely smaller than an amateur rider of the same height might buy!
Why is this? In the world of pro cycling, the slightest advantage determines victory or defeat. Thus it only makes sense that bike size would be a part of the strategy, too. And even if it seems opaque to us on the outside, surely the pros have a very good reason for choosing a petite bike.
Three main performance benefits come from the use of smaller bikes. These can be summarized as aerodynamics, frame stiffness, and handling.
Let’s check out each of these factors and better understand the pros and cons. It turns out small is actually a big deal when it comes to bike sizing in the pro peloton!
1. The aerodynamic difference.
Of course, with many things in the pro cycling world, the primary driver for selecting a smaller frame is any aerodynamic advantage it may offer.
A smaller frame presents a reduced front to the wind. The reduction in drag this results in is critical! That’s because overcoming air resistance can account for a pretty significant chunk of a cyclist’s total energy use. Especially when they are riding solo or on the front of the peloton, it makes a difference.
But it’s not just about the drag the frame itself. Actually, on a smaller frame, riders can take a lower, more aggressive position. A shorter head tube, often found on a smaller frame, allows for a greater “drop” from the saddle to the handlebars. Compact geometry might be chosen specifically to optimize a rider’s ability to streamline their body.
Read More:
Why do so many pro cyclists love wind tunnel testing? And does it really help optimize their rides?
From this, we understand that the frame is more of a tool allowing the rider to become “aero,” rather than the frame itself being “aero”…
This idea of smaller frames being more aerodynamic has been studied in research, too. Riding one frame size smaller can save a few watts, and for professional cyclists, every watt conserved or gained matters. A smaller bike might be a pretty big competitive advantage.
2. Stiffness and power transfer can help to max out speed on the bike.
Aside from allowing for a more aerodynamic ride, smaller frames have enhanced structural stiffness. This directly translates to more efficient power transfer.
Whyy, and does it really matter? Sure! Smaller frames naturally possess shorter tube lengths and form “tighter triangles” within their geometry. The increased rigidity resulting from this means a greater proportion of the cyclist’s pedaling force is directly converted into forward motion. Also, energy loss due to frame deformation (or, the bending of the frame when the force of pedaling it put on it) is kept to a minimum.
Using energy effectively is most important during the high-power efforts such as sprints, accelerating attacks, and long climbs. In these situations, maximizing energy transfer isn’t just helpful… it’s actually necessary for a top performance.
What’s the catch? Well, while it makes sense for smaller frames to be stiffer, some analyses suggest that frame stiffness between equivalent carbon frames of varying sizes may NOT be so significant. Still, maybe pros have a nuanced view of it. After all, the stiffness may vary in different directions, including laterally or torsionally, which is more important during out-of-saddle riding. Even a minuscule stiffness advantage could be helpful in a sprint!
3. Handling and agility help to navigate the parcours.
Finally, but still important, the compact geometry of smaller frames also contributes to improved handling and agility.
More than anything else, these improvements can help a rider survive the professional racing environment. Keep in mind, there’s no really point in being “aero” if you crash!
A smaller frame typically has a shorter wheelbase, also known as the distance between the front and rear axles. A more compact design makes the bike more responsive to input — not just turning the handlebars, but controlling the bike with the entire body. This enables quicker changes in direction and sharper cornering.
But these differences in handling remain a compromise. With smaller frames, riders often rely on longer stems to make the bike a better fit. However, these stems can also dampen handling and shift the weight of the rider forward.
Optimal handling for a professional cyclist is not a universal concept. Instead, riders might decide their ideal handling as an adapted and specialized characteristic. That may mean differences in frame size, stem length, and other components. As such, bike sizing can differ somewhat even for riders of very similar heights and body types.
Embed from Getty ImagesHow do pros compensate for small frames?
Despite all the advantages discussed above, the pros still need to find their desired riding position on a smaller frame. For this, they employ specific adjustments, often involving the stem and seatpost.
To compensate for the shorter top tubes and reach inherent in smaller frames, professional cyclists often use very long stems. They can exceed 130 mm or even 140 mm to extend the rider’s position forward! This helps to offset the reduced length of the frame.
While longer stems provide the necessary reach, as mentioned before, they can alter steering dynamics. Pros adapt to steering that feels slower or more “dampened” to find the right combination for safe riding in the peloton.
With a smaller frame, the seat tube is also shorter. For tall riders, a seatpost extension can reach the right saddle height for leg extension. Additionally, pros often position their saddles further back on the rails to reach their preferred hip angle. This is another important element of power delivery and can be influenced by the steep seat tube angles found on smaller frames.
Keep in mind that just like with amateur bike fitting, adjustments aim to optimize the rider’s three contact points: hands, feet, and saddle.
How can you tell when a pro cyclist is riding a small frame?
The visual characteristics of a pro’s bike (such as a pronounced saddle-to-bar drop, an elongated stem, and an extended seatpost) are often admired and sometimes even emulated by recreational riders!
However, these functional necessities are also the clues that a smaller frame is being adapted to a taller rider.
If you’re trying to see whether a pro is on a smaller bike than they “should” ride, look for the “slammed” stem and extended seatpost. The distinctive appearance of a professional’s bike is the consequence of a highly specialized bike fitting strategy!
How has bike fitting evolved over time?
The trend of professional cyclists riding smaller frames isn’t an isolated or recent phenomenon. Rather, this came about through decades of bicycle design and fitting philosophies.
Moving from traditional to modern geometry.
Historically, bicycle sizing was a much simpler affair.
The fit of a bike was primarily determined by the seat tube length, with a strong emphasis on standover height. In models from before the 1980s, the top tube length and other frame dimensions often remained static across different frame heights. This meant a taller rider on a larger frame would often feel cramped due to the same top tube length as a shorter rider.
The industry underwent a pretty significant transformation with the advent of “proportional sized” frames, largely influenced by Japanese manufacturers entering the U.S. market. In this modern approach, smaller frames feature shorter top tubes, and larger frames incorporate longer top tubes.
While this is generally an improvement for riders of “average” proportions, this shift also introduced greater complexity in sizing. For example, measurements like effective top tube length have become more important than the traditional seat tube length.
The current diversity in sizing systems and all the varying methods manufacturers use to measure frames for both pros and amateurs reflect this ongoing evolution.
Triathlon and time trial bikes have an influence across bike sizing.
The push towards more aggressive, forward positions in road cycling can be traced back to related disciplines like triathlon, which has fewer restrictive rules compared to UCI road racing.
Triathlon bikes push on the boundaries of bike fit, because they encourage riders to adopt more forward and aerodynamic positions. These positions have subsequently influenced road cycling. Shorter cranks and more aggressive saddle positions, which were initially pioneered in triathlon, gradually found their way into the road peloton over time.
Contemporary professional cycling is also increasingly driven by sports science, advanced data analysis, and the direct involvement of a team’s “aerodynamic experts.” This is especially true in time trialing, where riders may spend extensive time in wind tunnels learning how to be as aerodynamic as possible. A scientific approach can also move away from being comfort-oriented to promoting more extreme rider positions.
This is just one more way that the optimization of cycling and the “marginal gains” mindset has changed the sport over time.
Embed from Getty ImagesShould amateurs ride smaller bikes?
While the smaller frame strategy offers many advantages for pros, it still comes with inherent trade-offs.
One big compromise lies in handling and stability. Although smaller frames can offer agility, the necessary use of a longer stem will slow down the steering and dampen handling response. This can make the bike feel really “squirrelly” at low speeds, and adversely affect weight distribution for the rider.
And the extreme positions adopted by professionals, enabled by smaller frames, demand a lot of physical flexibility, core strength, and adaptation. Yes, that’s right: pros aren’t comfortable on these small bikes, and they simply have to get used to it. For recreational riders who lack conditioning or dedication to becoming as aero as possible, attempting to emulate these positions could be painful or maybe even dangerous.
It’s definitely NOT what you want to do for a comfortable bike setup.
Experts usually advise recreational cyclists against blindly copying professional setups. This is true for bike sizing as well. Bike fitting for amateurs looks a lot different than for the pros, because amateur bike fitters like the ones at your LBS prioritize different goals and outcomes.
For the average rider, comfort, injury prevention, and sustainable power output over long rides are going to be the most important. And a “fit first” approach, which aims for the rider to be comfortable and able to reach their own specific goals, is the most important for a good experience.
Embed from Getty ImagesRiding a small bike is a compromise, even for the pros!
So what do you think of why the pros ride these small bikes?
As with most things, it’s a mix of good and bad. Bikes are engineered for marginal gains: to optimize aerodynamics, enhance the power transfer, and improve agility, all within the confines of what’s possible within the modern peloton.
But this strategy doesn’t come without a price. And without a pro cyclist’s conditioning, flexibility, and truly remarkable ability to adapt… it would be difficult to ride such tiny bikes day-to-day.
For most cyclists, a personalized fit approach remains the best standard, not just for enjoyment of riding, but also for safety and health.
So if you’re feeling inspired to try a smaller bike yourself, think of all the reasons why the pros do it… and all the reasons why they may not want to!
Do you think you would be able to adapt to riding such small bikes as a pro cyclist? Why or why not? Let us know your views in the comments or on social media! ★
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