CH Aero disk cover - observations

Triathlon Forum
1

Bought a NOS Wheelsmith Mavic GP4 tubular wheel with Shimano 600 8-spd hub, 32spoke, to put the CH Aero on. Ebay Racing…

Mounting on this rim was easy, but the derailleur scrapes the cover when in the lowest gear, and I can’t adjust it to clear the cover without affecting the shifting. It just barely touches, so I’m riding it, figure CH Aero’s replacement policy is cheap enough to replace once there’s any significant damage. The double-head pump I have doesn’t fit into the wheel, so I had to use a frame pump, and buy a new floor pump that will fit.

3 different rears for this bike, the other two -
a clincher Ritchey Aero Pro rim with 32spoke and RS-100 8spd hub,
Hed Jet Deep tubular (alu rim with carbon fairing) 24 bladed spokes and Dura-Ace 8spd hub.

Weights: without cassette or skewer, and Continental Sprinter on the tubular rims, Michelin Sport on the clincher:
clincher 1750g
Hed 1400g
CH Aero 1800g
Nearly a pound more than the Hed, gave me pause.

Timings:
The race wheels (Zipp 440 front and Hed) are worth about 1-2 min over the clinchers, for 15 miles, by repeated tests on a training TT route and in races I’ve done for several years. I’ve never tested the Hed on its own.

So far on the CH Aero, one ride on the TT, a du 30k, and a 20k in a tri:
TT results were comparable with the Hed, not significantly faster. This route has lots of turns and other accelerations, so the result is expected.
The 30k was the fastest I’ve averaged in any race, 38km/h, 23.6mph, but it was perfect for the disk - flat, mild sidewinds on out and back, only 5 turns.
The 20k was in a race I’ve done 5 years running, descended the bike time every year, mostly by buying speed (aerobars, then a better frame, then race wheels, then… I’m running out !). Last year 32:51, this year 32:30 (avg 37.2km/h), similar wind conditions, mild to none, moderate rolling hills. Last year I was jetlagged, this year I had sore legs after standing all the previous day setting up/policing/cleaning up a childs’ birthday party. Hard to tell how these fine tapers affected each day.

What I notice most is that the CH Aero is spookily quiet, in calm conditions I can usually hear the wheels, but not with this combination. That’s encouraging, but the results so far are somewhat indecisive. Certainly the CH Aero will be a lot better than ordinary spoked wheels, but seems it’s only a small advantage over the Jet Deep. Still, every second helps…

On a really technical bike course with no/little wind, I think I’ll still run the Hed.

2

“but seems it’s only a small advantage over the Jet Deep.”

The Deep 90 is a very aero wheel, only slightly less aero than a trispoke according to the Hed website. I’ve found the same thing in comparing my Hed Deep with Ch Aero covers, but you’d not notice a huge performance difference with any other disc over the Deep either.

It’s amazing how quiet the covers are. None of the whoosh-whoosh that you get with “real” discs.

3

Anyone who has a real disk knows that you don’t have to buy a new pump - you need a disk wheel pump presta adapter, aka the crack pipe. Even with the CH Aero wheel cover.

4

I recently got one as well and I was surprised by how well it all went together. I had mine specifically cut out by Rich Sawaris at wheelbuilder to fit my Velocity Deep-V rims and powertap hub. I haven’t done any real tests on it but I will say it felt super fast (I think this is the correct terminology) compared to my Zipp 404s with Tufo brakes. I also have my derailleur brush lightly against the cover when I’m in my lowest gear.

BTW, I don’t need the crackpipe to inflate the tire…the valve cutout is deep enough to inflate the tire with a normal floor pump. A piece of tape goes over the cutout after inflating to create a nice smooth surface.

Great product.

ot

5

It may only be slightly faster than a Hed Deep. But how much cheaper is it? Also if you use a power tap it gives you the option of using your power meter in the race. I used a Ch cover over a Power tap at Ironman Arizona and I can not compare how fast I may have gone with a different wheel but I know that my marathon was much faster due to being fresher. Having wattage on the bike kept me from killing myself trying to maintain certain speeds with that wind. There were 4 times that my ego wanted to go faster when someone I knew passed me on the bike, however the wattage meter caused me to behave. I ended up passing 3 of the 4 during the marathon. I will write the 4 th one off to him being a very fit man who had a good race.

If you use a Power Tap a CH cover is awesome.

6

Anyone who has a real disk knows that you don’t have to buy a new pump - you need a disk wheel pump presta adapter, aka the crack pipe. Even with the CH Aero wheel cover.

the crack pipe would work, but it’s $12, and the new pump was $20. For that price, I’d rather have another pump…