Flo has published lots of their own numbers that should give you at least one more data point as the difference between depths.

Old article with lots of speeds and such.
Newer article without anything about disc wheels but still gives an idea between depths.

For most of those, you'll have to compare the relative time savings each wheel gives over their baseline wheel, the Mavic Open Pro. For example, the first article says that at 25mph (relative speed) a Flo 90 will save 419 seconds over 180km over the Mavic Pro while the disc will save 466 seconds. Therefore the disc is about 47 seconds faster over 180km than the 90.

---

Benjamin Deal - Professional - Instagram - TriRig - Lodi Cyclery
Deals on Wheels - Results, schedule, videos, sponsors

Always use a solid disc wheel on the rear.

Hambini's treatment of this is the best you'll get: https://www.hambini.com/...test-bicycle-wheels/
NB Not trying to market wheels.

If you want specific data then you need to be more specific about the wheels you're testing. A 80mm V-shaped rim with a 24 round spokes is going to test slower than a 60mm toroidal rim with 20 bladed spokes. A lenticular disc is going to test faster than a flat disc.

As for Swissside's data comparing their own, presumable similarly shaped 60/80/disc rear wheel are in line with what a lot of tests show.

Proven data is going to be hard to come by. Wind tunnel time is expensive and companies are only going to publish tests that show their product on top.

Thanks for that guys, both the Flo paper as well as the Hambini's summary will benefit me. Flo specifically gives another perspective, while Hambini gives a broader view.

https://www.wheelscience.com/pages/performance-data

Some useful comparisons. NB test on track therefore uniformly low yaw angles: unlike in 'real world' (on the road).

I somehow gave you a hint about my DT Swiss Arc 1100 80mm (newer version with 20mm internal width) and DT Swiss Arc 1600 62mm (also 20mm internal width). But you're right - I should have been more specific. Or... I should have made an asterix, that "please exclude the influence of a bike frame, tires size, hubs, spokes, rim-shape etc. All I'm interested in is a depth variable."

To the other point about companies publishing tests - don't you think that Swissside didn't make the best job at marketing here? If somebody new enters the page and sees "I can buy a disc for > USD 2000 and it will make me 35 seconds faster over an IM distance compared to my 80mm/80mm", then it's not an appealing advert. This is why I was curious about some real life data, or at least some tests at different average crosswind angles.

Good stuff, thanks Tomaz!

I've been wondering about this lately, to inform a possible purchase.

I have an older model Zipp disc (I think a 2008 Sub9, with a c. 19mm external width), am considering getting a new Hed Jet 9 wheelset, and wonder if the rolling resistance benefits of a wider wheel, coupled with a modern rim shape, would offset the aero benefits of the older disc.

Any thoughts?

I digitise a lot of wind tunnel data to use in course modelling and the data backs up what you're seeing
From my own tunnel testing
For a low yaw (<0.5deg average) day at IMNZ, switching a 78mm rear to a disc would save 19s of translational drag (add a bit more for rotational drag savings) for a 5hr rider
On a higher yaw day (7.5deg average) that increases to 42s

On the high yaw day, dropping from the 78 pair to a 58 pair costs 41s, or 21s if you pair the 58f with a 78r
On the low yaw day those numbers are 19s and 12s

It is much more important to pay attention to tyres/tubes than wheel depth

So comparing like-to-like a disc>80>60, but the actual magnitude of the difference will still depend on specifics. A 30mm tire on a narrow rim will have minimal differences between wheels, since there is little that rim shape can do to overcome a ballooning tire. A well shaped toroidal rim with an absolute minimal tire will exacerbate the differences.

As for advertising its certainly not the most logical pitch. I have to imagine that their target audience is bimodally distributed between very competitive athletes selling old stuff to buy new stuff and money-to-burn recreational athletes buying the one that looks fastest. Idk tho marketing is far outside of my area.