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aero disc wheel cover - my results(13 posts)

aero disc wheel cover - my resultsrockbender
May 14, 2003 11:13 AM
With very little information found from other's results, I set out to see if the CH Aero disc cover was going to increase my speed significantly on a mostly downhill course. I bolted the cover up to a Ult/OP wheel.

I picked a hill on the course and a designated spot that I wanted to hit at about 30 mph before tucking. I first did this with my K's, and then switched to the disc wheel and headed down again, measuring top speed.


Ksyrium: 43.6 mph
Disc: 44.3 mph

Is this significant? perhaps not. I could have been in a slightly different position, though I tryed to be very consistent. Furthermore, I only ran one trial of each wheel. What I did notice is that I had to feather my brakes to keep it under 30mph when I hit 'the spot' with the 'K' while I actually had to pedal to hit 30mph with the disc... noticible difference in inertial mass there (expected).

I rode the rest of the course with the disc and didn't notice an appreciable change in time.

Photo for those interested... apologize for the clutter!

Again, if any of you tri- or TT guys have any conclusive evidence on running discs, I'd be interested to hear it. I am leaning towards running the K's just because they are familiar.
how complicated was installation? nmJS Haiku Shop
May 14, 2003 11:39 AM
piece of cake...rockbender
May 14, 2003 11:52 AM
the installation was quite easy. I was actually going to use/try the cover last year, but it didn't fit right on the ksyrium - fits the OP profile fine.

All I had to do was remove the cassette, put the two sides of the cover on and joined them with 6 or 8 aluminum T-bolts. Replace the cassette and that's it.

I didn't weigh the assembly, but am guessing it added close to a pound on the rear wheel.
I've got the carbon versionMR_GRUMPY
May 14, 2003 11:56 AM
It's better than nothing, but no way, as good as a disc.
how often do you use it, and under what circumstances? (nm)rockbender
May 14, 2003 12:30 PM
I've got the carbon versionasgelle
May 14, 2003 1:51 PM
> It's better than nothing, but no way, as good as a disc.

Not true. See
May 14, 2003 2:41 PM
Do you work for biketechreview? In other words are you willing to share with us a summary of the information you have found?

May 15, 2003 6:20 AM
> Do you work for biketechreview? In other words are you willing to share with us a summary of the information you have found?

I don't, which is why I don't think it's proper for me to share these results. I am a subscriber, though, and have found the information well worth the small charge.
May 15, 2003 7:51 AM
understandable... thanks for the advice on checking out the article.
Here's some numbers from Analytic Cycling. . .js5280
May 14, 2003 12:18 PM

I look forward to hearing more about this subject. If a $60 disc cover is almost as comparable performance-wise to a deep section or tri-spoke which cost way more, that might be the way for me to go too. Any ideas on how the total weight compares? How much does the additional mass/inertia affect performance?
re: aero disc wheel cover - my resultsGreyhound
May 14, 2003 9:54 PM
Where can I find more info on these disk covers? Does the company have a web site? Any info would be appreciated.

May 15, 2003 8:58 AM
I am actually borrowing the cover from a friend, and thus am trying to find some info myself to make sure I want to use it.

The only place that I have seen sell/distribute it is

wish I had a tri-spoke for the front!
it is not bad if result is accuratecyclopathic
May 15, 2003 6:03 AM
you're looking at almost 5% drag reduction since resistance proportional to cube. Replacing wheel with best combo (tri-spoke front/disk rear) yields 10% drag reduction