Say that I ride olympic distances, typically flat and not that technical courses, and average (hypothetically) 22 mph over 40k. How much would I gain in mph if I switched my ‘normal’ road wheels (say Mavic Ksyrium as an example) wheels for a pair of deep-rim wheels (say Zipp 808)? Nothing else changes.
The cost is pretty high compared to most other things you can do to get more aerodynamic. On the other hand, most seem have them, so I assume there is some measurable benefit.
Maybe 0.5 mph if I was to take a guess based on using my training wheels vs. race wheels. I think the aero gurus; can probably tell you the exact grams of drag and tiem you’ll save. I think about the same as a road helmet vs. a aero helmet.
The disc wheel will make a fairly big difference. Throw in a 90mm front wheel and you will be noticeably faster. I’m not sure how much time you will gain exactly, but it would be minutes on a 40k time.
The measurable benefit is increased confidence in having a more awesome looking bike! That’s at least 10 mins of savings.
But really it’s hard to tell how much you’ll save is it varies from frame to frame even with the same wheels. Even a different yaw average day takes effect.
So I pretty much have nothing to add…
Flo wheels are one of the only companies to say you’ll save x time over an Ironman. With their disc, they say something like 9 minutes over an Ironman… IMHO I call bullshit. I think you’ll save 4-5 minutes with fast wheels (regardless of brand x vs y) in an Ironman (that’s less than 1 minutes Olympic).
Again, personally, I’ve only run heavy training wheels for every single day of training and then raced an Ironman with a very aero top, rented zipp 808s and a Giro A2 helmet. With all of that “huge” amount of savings; I would guess I went .5 mph faster over the whole course.
That’s really not that much considering I was more aero and I dropped a ton of weight with the better wheels. I think you’ll see a big difference in speed on decents, very very very little on climbs and .1 on flats.
And more than anything, if there was significant data to prove that setups save massive amounts of time; we’d have that data plastered everywhere by now but instead we still question “how much does it really save?” If you’re going to buy wheels, don’t spend more than a grand… I think after that you’re wasting money nit picking… aka buy Flo wheels new unless you can get some killer deal on used wheels.
If you’ve maxed everything else out - aero helmet, clean cables, good position (most important thing) - and you want a bit more speed, then I’d say they’re worth it. In my experience, all else aside, my deep wheels (not even wide/FC shape, standard V) might have saved me up to 2 mins in the 40K. This is just my gut feeling. Wide full-toroidal wheels might give you a minute more.
Flo wheels are one of the only companies to say you’ll save x time over an Ironman. With their disc, they say something like 9 minutes over an Ironman… IMHO I call bullshit. I think you’ll save 4-5 minutes with fast wheels (regardless of brand x vs y) in an Ironman (that’s less than 1 minutes Olympic).
But the faster you go, the more beneficial the wheels become. I wouldn’t call b.s. based simply on anecdotal experiences.
Aero wheels will save around about 100 to 200 grams of drag over a typical training wheel, depending on the wheels in question and what yaw angles you experience. Source:
https://docs.google.com/spreadsheet/ccc?key=0Agu_Y5SLfSFKdHZaREoyanBRVWtKcjNFbFpSa0ZfM3c#gid=1
and
http://www.aeroweenie.com/assets/img/data/flo.png
100-200g drag @ 30mph saved is probably more realistic average drag savings most of the time.
Now, 100g of drag saved @ 30mph is approximately 40 seconds save per 40k no matter how fast or slow you go. (per the aero rule of thumb: 0.1 lbs (50 g) of drag (at 30 mph) = 0.5 s/km = 5 W = 0.005 m^2 CdA = 0.0005 Crr )
Saving 100g of drag saves you ~40 seconds per 40k which is around 0.27mph assuming you were hovering somewhere around 1 hour for 40k to start with.
Depending on the wind and wheels in question you might save half, or double that.
Flo wheels are one of the only companies to say you’ll save x time over an Ironman. With their disc, they say something like 9 minutes over an Ironman… IMHO I call bullshit. I think you’ll save 4-5 minutes with fast wheels (regardless of brand x vs y) in an Ironman (that’s less than 1 minutes Olympic).
But the faster you go, the more beneficial the wheels become. I wouldn’t call b.s. based simply on anecdotal experiences.
Sure it’s personal opinion but none of their “research” is really definitive… so when we’re presented with a question without a definitive answer, personal opinion is one of the most logical ways to determine worth. If you go buy a TV at Best Buy, do you read the opinions to get a sense of how good or shitty a tv is or do you just take the facts that the company spits at you? I would hope you read the opinions; and read them with a grain of salt much like you should read the “research” these companies tell you.
This isn’t really true.
In terms of time saved, a slower rider will actually save more time over a fixed distance.
This is a non intuitive but true fact, which you can validate with physics if you want here: http://analyticcycling.com/DiffEqWindCourse_Page.html
Further complicating the question is that a slower rider will experience higher yaw angles, which might cause them to save even MORE time, with a disc, since discs do so well at high yaw.
9 minutes for an ironman is probably possible if the course was a crosswind the whole way compared to a really bad training wheel or something. I would consider it a slightly misleading marketing edge case =)
But the faster you go, the more beneficial the wheels become. I wouldn’t call b.s. based simply on anecdotal experiences.
How much would I gain in mph if I switched my ‘normal’ road wheels (say Mavic Ksyrium as an example) wheels for a pair of deep-rim wheels (say Zipp 808)? Nothing else changes.
From Jackmott above: Now, 100g of drag saved @ 30mph is approximately 40 seconds save per 40k no matter how fast or slow you go. (per the aero rule of thumb: 0.1 lbs (50 g) of drag (at 30 mph) = 0.5 s/km = 5 W = 0.005 m^2 CdA = 0.0005 Crr )
Fortunately for you, Ksyriums suck for aero, so you have a lot to gain. From the chart below, the difference between a single (old) Zipp 808 to Ksyrium ES front wheel is ~16W at 50km/hr. Add 8W for the rear wheel and another 4W for rotational drag brings us to 28W. Which, if the rule of thumb is correct, is ~112 sec in a 40k.
But note that you can get most of the way there with a decent aluminum rimmed front wheel and a disc cover on the back. You don’t have to spend a lot.
And if you use fast tires and latex tubes, you can gain even more.
The measurable benefit is increased confidence in having a more awesome looking bike! That’s at least 10 mins of savings.
But really it’s hard to tell how much you’ll save is it varies from frame to frame even with the same wheels. Even a different yaw average day takes effect.
So I pretty much have nothing to add…
+1
Actually, you may not go faster. But, your competition will go slower since their egos will be crushed upon viewing the awesomeness of your bike.
My usual training circuit is pancake flat and about 40k. At cruising speed (not race speed), I gain a bit over 1mph with a pair of Profile Design 80mm semi-carbon aero wheels. That’s about 19mph with the PD aero wheels versus about 18mph with stock (Shimano R501-30mm) wheel. I don’t have any head-to-head data to compare the two at race speeds.
I also use a faster tire on the 80mm wheels, so that’s part of the gain – that might explain why I show more improvement than the other commenters predict.
Unlike some who have provided REAL evidence, I go with the confidence people! I have run a rear disk and 404 zipps up front, I SWEAR that my HIM an IM speeds would’ve been at least 1-1.5 MPH AVG. slower without them. The only reason I say this is that my best splits are with them, and when I put my race kit together on my bike, I only use it for about 5 rides before my race and my rides are faster with less power output than in training without them on my usual routes. For my last IM, I did a training ride of 112 miles without my race wheels and struggled to avg. 18 MPH, my IM I averaged over 19 holding back and keeping even splits for both loops of the course. Deep wheels make a difference, to me anyway! Good luck. Plus, they make your ride look effin sexy!!!
Yep, tires are often a bigger performance improvement than wheels.
My usual training circuit is pancake flat and about 40k. At cruising speed (not race speed), I gain a bit over 1mph with a pair of Profile Design 80mm semi-carbon aero wheels. That’s about 19mph with the PD aero wheels versus about 18mph with stock (Shimano R501-30mm) wheel. I don’t have any head-to-head data to compare the two at race speeds.
I also use a faster tire on the 80mm wheels, so that’s part of the gain – that might explain why I show more improvement than the other commenters predict.
Flo wheels are one of the only companies to say you’ll save x time over an Ironman. With their disc, they say something like 9 minutes over an Ironman… IMHO I call bullshit. I think you’ll save 4-5 minutes with fast wheels (regardless of brand x vs y) in an Ironman (that’s less than 1 minutes Olympic).
But the faster you go, the more beneficial the wheels become. I wouldn’t call b.s. based simply on anecdotal experiences.
Sure it’s personal opinion but none of their “research” is really definitive… so when we’re presented with a question without a definitive answer, personal opinion is one of the most logical ways to determine worth. If you go buy a TV at Best Buy, do you read the opinions to get a sense of how good or shitty a tv is or do you just take the facts that the company spits at you? I would hope you read the opinions; and read them with a grain of salt much like you should read the “research” these companies tell you.
What I’m saying is this: a rider riding at 20 mph will see less of a gain than a rider riding at 25 mph. You can’t say a test claim is b.s. simply because you may be riding at a speed different than what a test is done at.
http://cyclingtips.com.au/2010/04/biggest-bang-for-your-buck-in-time-trial-equipment/
always loved this article for this conversation.
So a skin suit gives you more time than position…please.
They were comparing a ‘tuck’ with a ‘tuned tuck’ from wind tunnel
A before and after would be helpful as the original position may have been good…
figured that, but still do not buy into that article
.