WHY ARE TEAMS NOW USING “ALL-ROUND” AERO BIKES INSTEAD OF ULTRALIGHT CLIMBING BIKES?

The evolution of racing bike design

Over the last two decades, racing bike design has been defined by two dominant philosophies: the ultralight climbing bike and the aerodynamic time trial or aero road bike. Initially, teams made a sharp distinction between these categories—lightweight machines were reserved for mountain stages, while aero-focused designs were deployed on flatter, faster terrain. However, rapid advances in carbon fiber technology, computational fluid dynamics (CFD), and integrated component design have blurred these lines.

Historically, climbing bikes were prized for their featherweight construction, often flirting with the UCI’s minimum weight limit of 6.8 kg. These bikes sacrificed aero tubing shapes and stiffness for minimal mass. Aero bikes, by contrast, featured deep tube profiles, hidden cabling, and aggressive geometries, but often tipped the scales significantly heavier, making them less desirable for summit finishes. This binary choice dictated team bike selection strategies for years.

The UCI weight rule and its impact

A major turning point came with the UCI’s weight regulation, which froze the minimum bike weight at 6.8 kg. Manufacturers realized that, beyond a certain point, reducing weight offered no competitive advantage if the bike could not go below the legal threshold. This shifted engineering focus toward optimizing aerodynamics, stiffness, and rider comfort rather than shaving off the last few grams. As a result, aero bikes slimmed down, while climbing bikes became more aero-optimized, converging into the modern “all-round” aero bike category.

• Climbing bikes focused on grams, but gains plateaued due to UCI rules.

• Aero bikes shed excess weight with new carbon layup strategies.

• Teams began to see more value in reducing drag than chasing grams.

• Hybrid “all-round” designs emerged to merge climbing agility with aero speed.

The result is that teams no longer have to compromise between a climbing bike and an aero bike. Instead, they opt for a single machine capable of excelling across all terrains—reshaping professional cycling strategies and equipment choices.

Performance benefits of all-round aero bikes

The performance edge of all-round aero bikes can be quantified through a combination of aerodynamic savings, stiffness-to-weight optimization, and improved rider positioning. In real-world racing scenarios, these factors often outweigh the pure weight advantages of ultralight climbing bikes. The key lies in the physics of drag: at speeds above 15 km/h, aerodynamic drag is the largest resistive force a rider faces. On long mountain climbs, where gradients exceed 7%, weight still matters, but the crossover point where aero trumps mass occurs sooner than most fans realize.

Why aero matters even uphill

Studies and wind-tunnel data consistently show that an aero bike can save riders 20–60 seconds over a 40 km climb compared to a climbing bike, depending on gradient and wind conditions. Even on iconic climbs like Alpe d’Huez or the Stelvio, reducing drag contributes significantly to total effort. Teams have tested these differences extensively, and the consistent findings favor all-round aero bikes when performance is measured across entire race stages, not just final climbs.

Stiffness, comfort, and integration

Beyond aero advantages, all-round bikes deliver stiffness that translates into better power transfer, especially on sprints and accelerations. Modern frame geometries and integrated seatposts also enhance rider comfort, reducing fatigue in multi-stage races. Component integration—such as hidden cabling, one-piece cockpits, and disc brakes—adds to both performance and aesthetics, creating a seamless package optimized for speed.

• Up to 45 watts saved at 45 km/h with aero frames.

• Reduced rider fatigue due to compliance features.

• Disc brake systems improve control in mountain descents.

• Integration improves airflow and reduces mechanical drag.

For pro teams, these small percentages add up to decisive race outcomes. When a single bike platform can deliver efficiency across sprints, climbs, and descents, it becomes the logical choice. Hence, the all-round aero bike has become the standard weapon in WorldTour arsenals.

Strategic and economic advantages

The shift to all-round aero bikes isn’t only about physics; it also reflects logistical, financial, and strategic benefits for pro cycling teams. Running two distinct bike platforms—climbers and aeros—meant managing more equipment, spares, and rider-specific setups. This created inefficiencies in race support, added costs for sponsors, and limited adaptability when weather or stage dynamics shifted unexpectedly.

Simplifying team logistics

With all-round aero bikes, teams can equip all riders with a single platform adaptable to most conditions. This reduces the need for multiple frame inventories, spare wheels, and mechanics specializing in different setups. The logistical streamlining allows team cars to carry fewer bikes, saving space and reducing complexity during Grand Tours.

Sponsor and market alignment

Sponsors also benefit from this shift. Instead of marketing two flagship models, brands can highlight one halo bike that performs everywhere. This simplifies messaging and resonates with consumers who want one versatile bike rather than multiple niche machines. The commercial upside has further accelerated the adoption of all-round aero designs across the industry.

• Reduced logistical complexity in team support cars.

• Lower costs in production and inventory for manufacturers.

• Stronger consumer appeal for versatile bikes.

• Unified sponsor marketing and storytelling opportunities.

In addition, strategic race execution improves when riders know their bike can handle every terrain. The confidence factor—knowing that equipment will not be the limiting factor—translates into bolder tactics and more aggressive racing. This intangible yet powerful advantage underscores why ultralight climbing bikes are gradually fading into history.