I boosted a set of the Ksyriums from my brother-in-law’s bike when he went abroad (only things on his bike worth harvesting). I bought a set of Flo 60/90 in December. I change the two sets out on the same road bike.
The Ksyriums float up the hills, great sensation. Very light. The Flos don’t cut through the wind like I’d expected them to on long flat rides and don’t seem as fast as the 404’s that a friend lent me for a race in November.
I use GP4000S on both sets. All other parameters being equal, is there a chance the Ksyirums are the faster wheels on a flat to rolling course? And should I use them for the rolling-ish 70.3 I have in six weeks?
… The Flos don’t cut through the wind like I’d expected them to on long flat rides and don’t seem as fast as the 404’s…
While I don’t know which one is faster, all data indicates that they’re probably too close for you to actually be able to feel the difference. So, I’d suggest that your perception of their speed isn’t likely to be a reliable indicator of actual performance.
I don’t ‘feel’ much of a difference with my race wheels on. But I certainly ‘notice’ the difference in my times:).
Think about it though… The fastest wheels on the market will save you about 1-2sec / km. What does 1-2 seconds faster feel like over the span of a kilometer??
If it takes 100 seconds to travel 1km, do you think that going 98 seconds with race wheels will feel dramatically different?
But… Those seconds add up over the course of a race!
The Flos are faster; it’s just that heavier/more aero wheels feel more sluggish when you accelerate at slow speeds (and it’s hard to feel 0.5mph of aero benefit…ex. I don’t feel faster in an aero helmet, but I am).
I train on Ksyriums and they are great wheels (bombproof.mine are '03s and have been trued once), but as far as speed they are the “baseline” wheels often used when quoting time savings from tunnel tests.
I boosted a set of the Ksyriums from my brother-in-law’s bike when he went abroad (only things on his bike worth harvesting). I bought a set of Flo 60/90 in December. I change the two sets out on the same road bike.
The Ksyriums float up the hills, great sensation. Very light. The Flos don’t cut through the wind like I’d expected them to on long flat rides and don’t seem as fast as the 404’s that a friend lent me for a race in November.
I use GP4000S on both sets. All other parameters being equal, is there a chance the Ksyirums are the faster wheels on a flat to rolling course? And should I use them for the rolling-ish 70.3 I have in six weeks?
Thanks y’all
I know I own the company so it’s easy to say that I’d be biased but… as an engineer (not as the company guy for a minute) who has studied this stuff in wind tunnels and CFD, I’d HIGHLY recommend you race your 70.3 on the FLOs. I’d say the same thing if you had a set of Zipps, or HED wheels in your garage too. They’re just faster. As others have mentioned things won’t always “feel” faster even though they are.
Let me know if you have any questions.
PS… As Jackmott mentioned, the FLOs are quite a bit wider than the Mavic rims, are you certain the brakes aren’t rubbing?
I boosted a set of the Ksyriums from my brother-in-law’s bike when he went abroad (only things on his bike worth harvesting). I bought a set of Flo 60/90 in December. I change the two sets out on the same road bike.
The Ksyriums float up the hills, great sensation. Very light. The Flos don’t cut through the wind like I’d expected them to on long flat rides and don’t seem as fast as the 404’s that a friend lent me for a race in November.
I use GP4000S on both sets. All other parameters being equal, is there a chance the Ksyirums are the faster wheels on a flat to rolling course? And should I use them for the rolling-ish 70.3 I have in six weeks?
Thanks y’all
I know I own the company so it’s easy to say that I’d be biased but… as an engineer (not as the company guy for a minute) who has studied this stuff in wind tunnels and CFD, I’d HIGHLY recommend you race your 70.3 on the FLOs. I’d say the same thing if you had a set of Zipps, or HED wheels in your garage too. They’re just faster. As others have mentioned things won’t always “feel” faster even though they are.
Let me know if you have any questions.
PS… As Jackmott mentioned, the FLOs are quite a bit wider than the Mavic rims, are you certain the brakes aren’t rubbing?
Thanks Chris, your service has always been top-shelf.
I’m certain about the brakes.
Went for a race simulation ride today and even in winds up to 24mph I had a faster time at a lower HR than expected, and I understand the feel of the Flos better, thanks in part to these replies. I’ll be racing on the Flos.
I boosted a set of the Ksyriums from my brother-in-law’s bike when he went abroad (only things on his bike worth harvesting). I bought a set of Flo 60/90 in December. I change the two sets out on the same road bike.
The Ksyriums float up the hills, great sensation. Very light. The Flos don’t cut through the wind like I’d expected them to on long flat rides and don’t seem as fast as the 404’s that a friend lent me for a race in November.
I use GP4000S on both sets. All other parameters being equal, is there a chance the Ksyirums are the faster wheels on a flat to rolling course? And should I use them for the rolling-ish 70.3 I have in six weeks?
Thanks y’all
I know I own the company so it’s easy to say that I’d be biased but… as an engineer (not as the company guy for a minute) who has studied this stuff in wind tunnels and CFD, I’d HIGHLY recommend you race your 70.3 on the FLOs. I’d say the same thing if you had a set of Zipps, or HED wheels in your garage too. They’re just faster. As others have mentioned things won’t always “feel” faster even though they are.
Let me know if you have any questions.
PS… As Jackmott mentioned, the FLOs are quite a bit wider than the Mavic rims, are you certain the brakes aren’t rubbing?
Thanks Chris, your service has always been top-shelf.
I’m certain about the brakes.
Went for a race simulation ride today and even in winds up to 24mph I had a faster time at a lower HR than expected, and I understand the feel of the Flos better, thanks in part to these replies. I’ll be racing on the Flos.
Ok, pretty easy answer that the Ksyriums are slower aerodynamically than Flos (or any “modern” aero shaped deepish wheel such as Firecrest). So lets make it a little tougher, I have a set of the Reynolds DV wheels that are a few years old but super light (lighter than the Ksyrium SL my wife rides), tubular (Continental Sprinter tires) and 46mm deep. I am poor so it isn’t going to happen, but what if I switched the front DV out for a Flo 60 with GP4000S? (The rear wheel is covered so I’m not even including it in the question) In mostly flat conditions riding in the ballpark of 40kph what actual time savings might one expect between the two front wheels? I know that is probably impossible to say difinitevly, but theoretically would there be a calculable difference?
