Factor ONE 22% Faster Than Tarmac SL8? Wind Tunnel Truth Before You Buy
Recommended Gear for Better Riding
Aero claims vs independent wind tunnel data
“22% Faster”? Factor ONE vs Reality – and What You Actually Need
The new Factor ONE comes with some wild claims: “8% faster than OSTRO VAM”, “up to 22% faster than a Tarmac SL8”, “15% more efficient than a Cervélo S5”. Sounds amazing. But before you throw your current bike on Marketplace… what do those numbers really mean for you on the road?
First Question: Are You Chasing Numbers or Performance?
Be honest with yourself for a second:
- When you look at a new superbike, are you chasing watt numbers… or the feeling of riding something special?
- Do you want to ride faster on your routes, or own “the fastest frame in the tunnel”, because it sounds cool?
- If I told you the difference between the top 10 aero bikes is only a couple of watts with a rider on… would that change how you choose?
Pause here for 10 seconds
Picture your ideal ride: where are you, who are you riding with, what speed, what terrain?
Now ask yourself: what actually matters more there – 2 watts of aero, or comfort, fit and confidence?
The Data: How the Bikes Were Really Tested
To keep this grounded in reality, let’s use independent wind-tunnel tests from CyclingNews.
Wind tunnel setup (the boring but important part)
- Same rider, same position, same 56 cm size (or closest match)
- Speed: 40 km/h with the rider on the bike
- Compared to a Trek Émonda ALR (rim brakes, round tubes, shallow wheels) as a baseline
- Key metric: “Watts saved vs Émonda” – how many watts less you need to hold 40 km/h
In other words: this isn’t a bare frame hanging in the tunnel. This is as close as we get to “same rider, different bike, same speed, how many watts do you save?”
Factor ONE vs the Fastest Superbikes
Here’s a simplified comparison with a rider at 40 km/h:
| Bike | Power at 40 km/h (rider on) | Watts saved vs Émonda |
|---|---|---|
| Cervélo S5 (2025) | ≈ 273.1 W | ≈ 27.6 W |
| Factor ONE (Prototype) | ≈ 273.2 W | ≈ 27.5 W |
| Specialized Tarmac SL8 | ≈ 280.2 W | ≈ 24.5 W |
| Trek Madone SLR Gen 8 | ≈ 280.4 W | ≈ 24.3 W |
| Factor OSTRO VAM | ≈ 280.4 W | ≈ 24.3 W |
| Colnago Y1Rs | ≈ 276.8 W | ≈ 23.9 W |
| Cervélo S5 (previous gen) | ≈ 281.3 W | ≈ 23.4 W |
| Canyon Aeroad CFR | ≈ 282.1 W | ≈ 22.5 W |
So yes, the Factor ONE is absolutely in the top tier. Nobody is arguing that. But notice something:
The new Cervélo S5 and Factor ONE are basically tied. The difference between them is 0.05 watts – well inside the error margin of the tunnel.
Question for you
If two bikes are effectively identical in aero performance, what decides for you then?
- Brand story?
- Ride feel and handling?
- Price and spec?
- Or how it looks in your photos?
Breaking Down Factor’s Claims
1. “8% faster than OSTRO VAM 2.0”
If we look at the actual power needed at 40 km/h with a rider, the picture is much simpler:
- Factor ONE: ≈ 273.2 W
- Factor OSTRO VAM: ≈ 280.4 W
That’s a difference of about 7.2 W, which works out to roughly 2.6% less power needed on the Factor ONE at 40 km/h.
So in a neutral, rider-on comparison, the realistic gap is around 2–3%, not 8%. Where the “8% faster” number comes from is unclear – but it’s not what shows up when you compare the complete power numbers from the same test.
2. “Up to 22% faster than a Specialized Tarmac SL8”
Using the same logic, we compare full power, not just “watts saved”:
- Factor ONE: ≈ 273.2 W
- Specialized Tarmac SL8: ≈ 280.2 W
The difference is about 7.0 W, which is roughly 2.5% less power for the Factor ONE at 40 km/h.
That’s still a strong result, but it’s nowhere near “22% faster” when you look at the complete rider-on power numbers from the same testing protocol.
3. “Around 15% more efficient than a 2024 Cervélo S5”
Against the previous-generation Cervélo S5 in the same dataset:
- Cervélo S5 (previous gen): ≈ 281.3 W
- Factor ONE: ≈ 273.2 W
That’s a gap of about 8.1 W, or roughly 2.9% less power required by the Factor ONE at 40 km/h.
So again, if we base the comparison on the complete power numbers, the realistic difference is in the 2–3% range, not 15%. And when you compare the Factor ONE to the new 2025 Cervélo S5, tested on the same day, they are essentially identical in required power.
In other words: when you look at the full picture – the actual watts you have to push at 40 km/h – the Factor ONE is clearly among the very fastest bikes in the world, but the gaps to other top superbikes are in the low single-digit percent range, not double digits.
The pattern is clear: Factor’s ONE is genuinely fast. But the percentages in the marketing do not line up cleanly with independent, rider-on wind tunnel data.
What Do 2–3 Watts Actually Mean for You?
Let’s translate the hype into something you can feel.
Imagine there’s a 3 W difference at 40 km/h. On a 30-minute climb at around 15 km/h, because aero drag scales with speed³, that becomes roughly: 0.16 W difference.
Over 30 minutes that’s about one second.
One. Second.
So ask yourself:
- Would you notice 0.16 W on a climb?
- Have you ever finished a 30-minute climb and thought, “if only my bike was one second faster”?
- Or is your real limiter your legs, your weight, your pacing, your sleep, your stress?
What Do You Actually Want From Your Next Bike?
At the sharp end of aero, the differences between the top bikes are small. The differences in ownership experience are huge.
- Are you willing to trade comfort for a few theoretical watts?
- Do you want a bike that feels stable in crosswinds, or the one that “won the tunnel”?
- How important is brand identity to you? Are you buying speed, story or status?
- What’s your real goal next season? Faster group rides? A Gran Fondo? Racing? Just looking and feeling pro?
None of these answers are “right” or “wrong”. They just need to be honest.
A simple exercise before you spend thousands
- Write down your top three goals for the next 12 months on the bike.
- Next to each superbike you like, write how it helps those goals – beyond aero watts.
- If a frame doesn’t clearly support a goal, ask yourself: do I want it, or do I just want the idea of it?
Need Help Deciding What’s Actually Right for You?
If you’re still thinking, “OK, cool data… but what should I buy?”, that’s exactly where we can help.
At Approved Cycling we build custom bikes starting from the question: “Who are you as a rider, and what do you really want this bike to do for you?”
Want to talk it through and match the right frame, wheels and fit to your actual goals – not just the marketing slides?
Click here to book a call or visit the shop and let’s design the bike that fits your riding, not someone else’s advertising.
