So what’s the scoop on these, from those of you who use them? There are a few companies who make boly-on disk wheel covers. I would thing they would be lighter than a regular disk…do you still reap the benefits?
I got mine at wheelbuilder.com. They are heavier than a regular disc and not as sexy, but from a performance perspective they are pretty similar. Oh yeah, they don’t hum like a real disc either. For $70, it is a pretty sweet deal if you are on a budget.
Plus, if you wreck one wheelbuilder will replace it for $12.
This is the #1 asked question on ST. A disc is a disc is a disc. I own CH Aero covers from excel sports as well as a RENN disc from bikesport. No difference in performance. You’ll be fine with them. Basically they are discs for those on a budget. Good luck.
As mentioned, a disc is a disc. I’ve used a CH Aero cover. They work best with a basic box rim but if you’re careful they can be trimmed down to fit an aero wheel as I did with a Hed jet 60.
I did the do-it-yourself cover out of monokote like they use on model airplanes, 16 bucks and a little bit of work, works great.
klehner has a monokote wheel and it looks pretty cool, it mathces his bike’s paint scheme. When I first saw it, I thought it was a disk. And Ken’s pretty damn fast!
I just bought one from wheelbuilder. $70 trimmed to fit my PT and Mavic rim. Took it out the other night to test it out. Over a 5-mile loop, I was 5 seconds faster with the disk despite my average watts being 8% lower.
As for weight, according to my scale the cover by itself weighs 390 grams.
www.ltcycles.com has one that is made of carbon that weighs 200grams. They are sold out for the season, but I thought someone said they were $125 - or $50 for a 1/3 lb weight reduction.
*I have run a CH aero cover for several years. It is now pretty ugly up close but then the rest of my ride ain’t much to look at anyway. I have decent bike splits with it. For the money I’d recommend it. It does seem heavy though. I think it is best for straight, flat courses. I have been switching to a more conventional wheel for courses that have a lot of turns and or climbs. The wheel/cover seems a bit sluggish in accelerating out of the corners. I have been thinking about building a monocote cover as it seems that it should be lighter *
Are they easy to take on and off? Would it be a waste to put it on a Zipp 404?
Somebody posted a picture of a 404 with a custom cut disc cover that a custom wheel builder had built for him. Essentially it looked similiar to my Hed Jet 60/CH Aero cover. It would lack the coolness factor of a full Zipp disc, but it would be every bit as fast.
The 404/disc is at www.wheelbuilder.com.
Is it a couple minute process? Do you have to remove the cassette? In other words, could you decide at the last moment before a windy/rainy race whether to use it and then quickly install it? Since it’s usually dark when I get to the transition area, I don’t want to be futzing around too much with this. Might use up too much of my adrenaline.
I will be doing moo next year, would it really be of any benefit looking at time savings and energy use?
Thanks for the info.
Personally, if you want a separate race wheel (i.e. wheel with disc cover), you’re not saving a huge amount of money over a new Renn 575, or even better, a used but in good shape Renn 575 (often available in the classifieds here). Then you have a purpose built disc wheel without the worry (no matter how small or unwarranted) of screws coming loose, etc.
Chris
heavier, not lighter, but very nearly as aero. Here’s my report:
Bought a NOS Wheelsmith Mavic GP4 tubular wheel with Shimano 600 8-spd hub, 32spoke, to put the CH Aero on. Ebay Racing… cost $60, plus the CHAero itself, comes out cheep cheep.
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 buy a new floor pump that fits.
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 not unexpected.
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. 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.
I am interested in these. can you give a bit more detail on how they install? Having trouble picturing
http://www.excelsports.com/new.asp?page=8&description=Wheel+Cover&vendorCode=CHAERO&major=1&minor=24
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what realistic time gains or average MPH’s do you see using one of these???