Colnago Y1 Rs – aero or NO GO ?

The Colnago Y1 RS (2025 model) represents a significant aerodynamic and structural design evolution compared to its V4 RS predecessor.

These are my opinions on the bike’s possible performance characteristics, innovative features, and problem areas.

More: Colnago Y4 Rs Technical Paper

Colagno’s claims

Tests … show that the Y1Rs requires 20 fewer watts than the V4Rs to maintain a speed of 50 km/h.

That’s a lot of watts, albeit at a speed most of us could not achieve outside of a group. Also, the earlier V4RS was about as aero as a Raleigh chopper, so aero savings weren’t hard to make. That said, I  REALLY like the looks of the new Y1 RS, and it certainly looks aero to me. Here are some more thoughts

Background and Design Insights

The predecessor had gaps all over the place, boxy frame sections and non-modern aero-geometry around the cockpit/head tube and seat tube.

Innovations in the Y1 RS

The Y1 RS addresses the issues. Key improvements include:

• Frame Geometry and Aerodynamics:
  • Air gaps between each wheel and the frame are much reduced but within UCI limits, likely improving airflow.

• • Slender tube shapes replace the boxy sections, reducing drag.

• • The hinged steering in the head tube and fork legs exhibit deeper and more aerodynamic profiles.

• Integrated Components:
  • The handlebars feature a unique design that minimises pressure drag.

• • The hinged fork and steerer assembly allow for a more compact, aerodynamic head tube structure.

• Reduced Frontal Area:
  • The bike’s frontal area has been reduced by 19%, significantly improving the overall drag.
  • Of course, the frontal area of the rider is much greater.

• Structural Adjustments:
  • The rear triangle has been modified from a traditional double triangle, requiring reinforcement (weight and bulk) to reinforce joints.

• • The bottle cage positions are designed to be partly integrated into the frame aerodynamics at speed and effectively fill a large part of the air gap in the front ‘triangle.’

Controversial Features

The Seatpost design supposedly adds some comfort. I doubt this. If this frame flexes slightly vertically for comfort (compliance), I can’t see the joints holding out too long, which is why Colagno reinforced them and why it likely will be stiff (which is fine).

As counterbalance, the narrower BB would likely reduce pedalling stiffness.

At over 1400g, the weight is light by historical standards but not modern ones. Perhaps it’s more than 400g heavier than some modern race frames. A more aero frame should trump a less aero, lighter frame on the flat.

The handlebars are an odd shape but probably quite aero. I like how they look but would worry about their adjustability – or lack of it.

What else?

You might as well get aero Qarbon aero chain rings, aero brake rotors and an aero rear derailleur (here’s how to make one from a Coke can…seriously) cover while you’re at it. Or you could buy a TT bike and be done with it 🙂

When viewed from the front, the forks do not look as far from the wheel as I would expect for a latest-gen Aero bike but there will be UCI limitations on this.

Or, as the company says,

Optimization of tube position. Tubes position has been optimized to achieve the best aerodynamics, without compromising stiffness and weight (ex. DT curvature and **distance from the wheel**)

Conclusion

I’d like one for racing in 2025!

Whilst its aerodynamics represent a step change for the better compared to its predecessor, I imagine they perform similarly to other leading aero race frames. I quite fancy the latest Cevelo S5 but would admit that the Y1 RS might edge it in a wind tunnel.

The wattage savings are unlikely to be realised by 99% of the readers of this post as we can’t solo ride at the test speeds. We could hit those speeds on significant downhills. Still, we would have lost time going uphill with the extra weight—furthermore, aerodynamics change on the flat in a group ride when we can hit those speeds; likewise, aerodynamics change in a sprint when the bike and rider are ‘all over the place’ compared to the rigidity of the wind tunnel tests.

The manufacturer has addressed numerous aerodynamic details, but a modern aero bike’s separation between the forks is less than expected (due to UCI rules).

The weight would be acceptable, but I would worry about the bike’s adjustability.

I am interested in seeing how the integrity of the reinforced area at the bottom of the seat post holds out.