What are your opinions on them?

I've a pair of CH Aero disc covers. They're nice for time-trialists on a budget. Wouldn't want to use them much outside of races, though.

Good for bike polo.

Look neat.

Provide some of the advantages of a true disc wheel.

Provide all the disadvantages of riding in crosswinds.

Are cheap.

does not seem aero

I was curious how well they helped aerodynamically. I have only seen one or two in person and i don't know too much about them. I've asked around locally and gotten mixed opinions. Some think they are pointless and just extra weight but others think they do help.

I have one for my poor-man's TT/tri bike. They add a bit of weight but I don't think my Open Pro/wheelcover combination is significantly heavier than a true disc wheel. I thought there was data out there showing that they're just as aerodynamic as a true disc. Of course, most of those analyses show that the true bang for the buck is an aero helmet and tri bars.

Wheelbuilder.com makes nice covers.

https://www.wheelbuilder.com/store/aero-disc-covers.html

This is really hard to imagine considering high end disc, such as zipp can actually produce slight forward lift. Also there is a power advantage to using a real disc.

From WheelBuilder's website:

"Note: The covers are not currently compatible with track, tandem, or front wheels."

Was bummed when I saw that.

They're no fun in a cross wind, or traffic since a large vehicle speeding past in the same direction you are riding can create an aero push on the disc.

I don't think you can even use those as spoke cards. Try a little older floppy.



It would be real funny if polo people create a disk wheel-ish thing using many of these. I am pretty sure you can considering how light and thin they are.

i sell adspace on my disc wheel to local companies

Yeah. It's probably comparable to the old ones that were just flat. Not the lenticular, dimpled ones.

If you don't think a disc and bars help out, you've obviously never ridden one.

I dropped over 50 seconds with bars + Disc + Trispoke on a 10 mile TT, still completely undialed in (as in my aero position was pretty ****ty), even after not training as hard (Season ended before I could bust out the big guns), versus track drops and 32 spoke Deep V's.

My Zipp 900 weighs less than my Mavic Aksium Equipe spoked wheel, but then again, it's a very expensive disc.

What's worth noting is Zipp's construction technique of the disc has not changed much in the last 20 years. The hub and rim edge are better but it's still a sandwich foam core carbon wheel.

The newer lenticular wheels from zipp (and HED as well) are actually spoked wheels with a very light cover on them, which is why they are not track compatible, as they're not very stiff (They're more marketed towards triathletes/pro skinny TT racers).