• Increase font size
  • Default font size
  • Decrease font size
Home Blog Zipp 950 Disc vs Wheel Cover

Zipp 950 Disc vs Wheel Cover

E-mail Print PDF

In 2003 I tested a CH aero wheel cover (that company has since been bought out by wheelbuilder, where the price instantaneously went up from a reasonable $40 up to $80+) against a Zipp 950 disc in the Texas A&M wind tunnel.

That test and trip to Texas probably cost me around $5000 (off the top of my head)...seeing as how that is a sizable chunk of change, I requested anyone who viewed that data sign a non-disclosure agreement.  Y'know, cuz, I'm a capitalist and all!  :-) I've got probably a half dozen signed NDA's laying around here from members of the manufacturing community and regular Joe's, so to speak.  Over the years, I've distributed some of these initial disc vs wheel cover results as part of this wheel data package:

...and I've relied on a gentleman's agreement to keep that data confidential...y'know cuz I paid a financial and stress-based toll to acquire these data!  Since the beginning of this adventure, I've had maybe a half dozen folks leak the data on various public internets forums over the last 7 years.  But thanks to my helpers out on the internets, I've usually rectified the situation in short order...y'know, copyright law gets forum owners' attention pretty quickly, it seems!

Well, it seems topica is the last hiding place for gems like this where Andrew Coggan PhD, for whatever reason, decided to talk about what he thinks my hard earned data taken at A&M says:

In retrospect, it makes sense that around this time, I started selling fewer of my wheel reports.  Bummer, for me, huh?!?

Curiously, though, it turns out that I was able to measure a difference between a zipp 950 disc and a CH aero wheel cover in the A&M wind tunnel...and at beta=0 (no wind/dead calm) the wheel cover measures slower, fwiw.

Too bad I didn't have the budget or time to control for the tire that was put on each of these wheels (one clincher and one tubular) - now that would have been interesting!

Anyway, getting back to that group of folks that signed the original non-disclosure agreement over 7 years ago...well, it turns out that the guy (Andrew Coggan, PhD) who penned what was written in the ibike topica link above, was part of that group who gave me their word they wouldn't talk about what I tested.

I'll leave the legal issues and ethical judgements up to those reading at home.