i just wanted to help the economy…but spending 2 k on a set for my wife who will have a hard time making the imcda bike cutoff …im wondering if their would be any benefits…shes a good bike handler,i dont think the wind will be a factor…how else could i spend the money to help her if the wheels only help the quicker crowd? just curious
Aero stuff actually gains slower people more time. The end.
She wants it. You buy it.
Aero stuff actually gains slower people more time. The end.
thats what i thought …but theres been debate on the effects of zipp wheels at such low speeds
at sub 15mph she will be subject to high yaw angles
so for the rear a disc will definitely be best, and that only costs you $75 or so for a cover for her current wheel.
for the front a HED 3 would probably be better than an 808, due to her being subject to more extreme yaw angles due to her slower speed.
other ways to help:
make sure she is on low crr tires
aero helmet
good position
pedal harder!
actually i was going to get the 1080s for my p3c and give her my 808’s…
actually i was going to get the 1080s for my p3c and give her my 808’s…
Aha, nothing wrong with with that plan then. I would still put a cover on the 808 rear though!
They will definitely be faster than a normal rim unless the wind is blowing her all over the road.
A deeper rear wheel makes the bike easier to handle, so an 404+disc would be a better option than 808s. An 808+disc would actually be easier to handle than a pair of 808s. Basically, in the simplest terms, the deeper rear wheel pushes you into the wind more than the deep front pushes you away from the wind, which is why it’s better to get a “mismatched” pair. So I’d say 606s or 909s or 999s. But probably not a straight up 808 pair.
As others have said, the wheels will be more of a benefit to her in terms of net time savings (though not percentage) than someone riding faster. Then again, if she averages <15, for most people that means usually they probably ride between 10 and 20. I’m sure you could bell curve it out. But my point is that to average sub-15, she’s also probably going to spend a fair bit of time going faster than that. At the much slower speed - say 10ish - she’s probably climbing.
That being said, if you wife is going to have a hard time making the cutoff, a bike fit is the first thing I’d make sure she had (not saying she doesn’t, but if she doesn’t that’s what I’d get first), and the second thing is maybe a coach to help get her ready for the race. If she has all that already, then by all means, get the wheels. But the last thing you want is for the new wheels to get shelved because she has a bad experience at Ironman, so I’m just thinking of some things along those lines.
But yes, the wheels will help her out whether she’s first or last off the bike.
i just wanted to help the economy…but spending 2 k on a set for my wife who will have a hard time making the imcda bike cutoff …im wondering if their would be any benefits…shes a good bike handler,i dont think the wind will be a factor…how else could i spend the money to help her if the wheels only help the quicker crowd? just curious
for 2K…she should get that speed up a bit first and earn the things 
A deeper rear wheel makes the bike easier to handle, so an 404+disc would be a better option than 808s.
i have the 808s already…1080s for me still looking or? i avg 19.4
cda is a hilly protected course…
i could rent the 1080s but
1080s, according to hed’s data, are faster than 808s at all yaw angles.
they are heavy though!
how about an 1080 front for you
give your 808 front for your wife
and disc covers for both of you?
i swear wheelbuilder should sponsor me!
A deeper rear wheel makes the bike easier to handle, so an 404+disc would be a better option than 808s.
i have the 808s already…1080s for me still looking or? i avg 19.4
cda is a hilly protected course…
i could rent the 1080s but
I recently interviewed top tech execs from both HED and Zipp for a little snippet we did on both company’s wheels. Both HED and Zipp told me that if a person isn;t consistently *over 25 M.P.H. *they should stick to 60 millimeter deep rims as opposed to deeper 80 and 90 millimeter rims.
The 60’s have a better, more efficient aspect ratio for lower speed regimes. Also, they are lighter and less affected by crosswind turbulence. For a rider between 10-17 M.P.H., especially on a rolling course, aerodynamics *do *still play a role, but a small(er) role relative to weight and stability. When it comes to rim depth slower (rider speed) equals lower rim profile. A lighter, more stable, slightly less turbulent shallower section wheels will both *feel *faster and actually be faster to a rider in the 15 M.P.H. regime than would a heavier, more turbulent 80 millimeter deep rim.
I know this has probably been discussed a bazillion times here, but can someone give me a quick executive summary on the theory of when aero wheels become truly beneficial and at what point their marginal utility diminishes? I’ve been contemplating back and forth lately whether or not to front the coin for a nice set of race wheels, but I’m still not sure whether the benefit would justify the cost. Just for a little background, I just picked up the sport last year and was averaging between 21-22 for oly distance, and a shade under 20 for the one HIM I did. This was on a road bike with Easton Circuits. Would I be a good candidate for deep profile wheels and if so, what depth(s) should I be looking for?
I recently interviewed top tech execs from both HED and Zipp for a little snippet we did on both company’s wheels. Both HED and Zipp told me that if a person isn;t consistently *over 25 M.P.H. *they should stick to 60 millimeter deep rims as opposed to deeper 80 and 90 millimeter rims.
The 60’s have a better, more efficient aspect ratio for lower speed regimes. Also, they are lighter and less affected by crosswind turbulence. For a rider between 10-17 M.P.H., especially on a rolling course, aerodynamics *do *still play a role, but a small(er) role relative to weight and stability. When it comes to rim depth slower (rider speed) equals lower rim profile. A lighter, more stable, slightly less turbulent shallower section wheels will both *feel *faster and actually be faster to a rider in the 15 M.P.H. regime than would a heavier, more turbulent 80 millimeter deep rim.
Yeah, I think you’d be hard pressed to beat the 404 front + disc rear as a “do it all” pair.
Aero wheels always have utility. Everyone is a candidate unless handling issues sacre you.
You don’t need to spend a lot though.
-
disc cover for the rear $100. a disc/disc cover is almost always the best for the rear
-
$400ish for a used flashpoint 80 or hed jet 90
with that you have 95% as good a wheelset as anyone for $500
I know this has probably been discussed a bazillion times here, but can someone give me a quick executive summary on the theory of when aero wheels become truly beneficial and at what point their marginal utility diminishes? I’ve been contemplating back and forth lately whether or not to front the coin for a nice set of race wheels, but I’m still not sure whether the benefit would justify the cost. Just for a little background, I just picked up the sport last year and was averaging between 21-22 for oly distance, and a shade under 20 for the one HIM I did. This was on a road bike with Easton Circuits. Would I be a good candidate for deep profile wheels and if so, what depth(s) should I be looking for?
Blasphemy! Everybody knows the key to going fast is finding the deepest, most dimpled, most bulging, toroidal Zipp wheels possible! 
Blasphemy! Everybody knows the key to going fast is finding the deepest, most dimpled, most bulging, toroidal Zipp wheels possible!
well that more or less true until the wind at your races starts to annoy you to the point of pedaling less hard
also ignoring the Zipp, and dimples parts
=)
I’m not averaging > 25mph for longer distances, yet no race I’ve ever entered has had a hint of crosswinds destabilizing me on a hed jet 90
perhaps a lot of iron and half iron distance races take place in more exposed and wind prone areas though?
Hello Tom and All,
I always enjoy your writing and comments. Thanks.
I read your comments attributed to Hed and Zipp. Their comments seem to be in conflict with their website advice on chosing wheel sets.
For me, a slow age grouper, "too aero’ is an oxymoron. I can agree with “too heavy” or “too twitchy” for deep wheels in some conditions, but overall, the slower I go, the more I think deep, deeper, and deepest rim wheels help me go faster.
As the Hed site says relative to apparent wind - the slower you go the more apparent the effective crosswind and the more you need a wheel that stalls at greater yaw angles.
Deeper rims stall at larger yaw angles … hence the deeper rims are more useful to slower riders than fast ones, as long as you are not on hills over 6% to 8% and you do not have control problems in the wind.
(This is yet another example of life’s being unfair - the fast riders not only do not have to ride for as long as most of the age groupers - they can do it with lighter wheels since they have less apparent cross wind.)
It appears (to me) that the additional weight of the deep rim is trumped by it’s superior cross wind performance capability for most triathlon courses.
I find my Zipp 808 front wheel easier to control in gusts than the Hed H3 and have only seen a very few steep downhills in gusts and traffic where I had to slow down or die.
If the wind was likely to be very strong and very gusty over a good share of the course I would opt for a 404 in front so I could stay in an aero position and not have to sit up and use the base bar.
For the rear my preference would be a disk (if legal) or a 1080 or equivalent.
If there was no crosswind in an out and back course then the lightest wheels like a Zipp 202 would be fine - but it seems that there is usually some wind.
What do you think?
Cheers,
Neal -------------------------------------------------------------------------------------
Tom Demmerly:
http://forum.slowtwitch.com/gforum.cgi?post=2225050#2225050
Now, one thing that HED and Zipp both mentioned to me is that the wheels that guys like Armstrong are riding are not the wheels us AG’ers should be on. Here’s why: I’m a decent AG cyclist in local triathlon terms. I often have the fastest or second fastest bike split in my AG and one of the better bike splits of the day in a small local tri.
My average speed seldom tops 23 MPH for an Olympic distance with an occasional 23.5 MPH average and a few 22.8 MPH average thrown in. The HED 3C and HED 3C Deep especially along with all front wheels over 60 mm deep and most rears over 80 mm deep are actually a little too deep for this speed regime.
In other words, when you take into account all the factors of wheel performance: Weight, cornering, crosswind stability, aerodynamics and rolling resistance then the super deep wheels are too heavy and too aero for the “low” speeds us AG’ers ride at.
Now, If we were up around 26, 27, 28 29 M.P.H. average speeds then we may benefit from deeper section fronts such as used by Lance and the really fast guys capable of averaging 30 MPH plus.
In short, unless we are are very, very fast on the bike- well above 25 MPH average speed- then we are fastest on something about 60 mm deep with wire spokes in the front for the best overall combination of weight, aerodynamics, cornering and stability. --------------------------------------------------------------------------------------------------------------------------------------------
Hed Wheel Website:
http://www.hedcycling.com/aerodynamics_technology/yaw_calculator.asp
Yaw Calculator:
Which wheels? 60? 90? H3? You’ll need to know a few things.
First, wind (or yaw) angle has a big effect on how a wheel performs. Second, there is “meteorological wind” and “apparent wind”. The weatherman on TV or you with a handheld anemometer can figure out the meteorlogical wind - it’s just part the current weather conditions.
Apparent wind is what you get when you factor your speed and direction into the existing weather.
Apparent wind what’s important for picking wheels.
So: At 27mph (a good 40k speed in a headwind) a 10 mph ENE wind (60 degrees) gives an apparent wind of 15 degrees. At 19mph (a good irondistance speed in a headwind) the same ENE wind gives an apparent wind of 20 degrees.
Using the two examples and wind tunnel data about wheel drag at different wind angles we can compare Stinger 90s to H3s for our two riders.
In a 40k race, the roadie, going 27 would see only 1 second difference between the two wheelsets.
He might opt for stingers because they are a little lighter than H3s.
The triathlete, going 19mph would go 40 seconds slower per 40k on Stingers compared to H3s.
After calculating a few scenarios, it is obvious why apparent wind is important. A zero degree headwind just does not occur out on the road, and this is why when we make a wheel, we design for and test incrementally to 30 degree wind angles.
A working knowledge of what windspeeds and angles affect bike wheels has directed Hed’s design process for 17 years, ever since this program was a nerdy, number only program on a floppy disc.
We’re enthusiastic about sharing this calculator.
More tools are in the works to help you pick the fastest wheels.
Zipp Website:
CROSSWIND CONTROL
It’s a common concern that deep section rims and discs are difficult to control in crosswinds. But in our experience, most riders can comfortably handle these wheels, especially after a few rides. In fact, our deepest rim, the 1080, is no more affected by crosswinds than a less aerodynamic tri-spoke.
That said, smaller riders should consider shallower rim profiles like the 303 and 404 to find the most aerodynamic setup possible without compromising control.
But for most riders under most conditions, a 1080 front wheel with a rear disc is entirely manageable.
AERODYNAMICS VS. WEIGHT
Since advent of deep profile rims, the tradeoff between aerodynamics and weight has been the key issue in wheel selection.
As any racer knows, lighter wheels are better for climbing and accelerating, and aero wheels roll faster on flat terrain and descents.
While there’s no hard and fast rule to choose one or the other, we find that aero usually trumps weight except on courses with multiple steep climbs (>8% grade).
On the other hand, your size, riding style, and – of course – personal preference are important considerations.
For Hilly Triathlon:
If you miss out on the dimpled hubs and personalized colors of ZEDTECH, the light and aero 1080/808 setup still offers the world’s fastest non-disc as your rear wheel and the wheel that it dethroned up front.
Done IMCDA whith Hed 3 and got hammered with the wind sending me across the other side of the road, i would stick with the 404 zipps, nice lightweigt wheel, could for climbing those hills and a lot less to catch the wind
.
… Basically, in the simplest terms, the deeper rear wheel pushes you into the wind more than the deep front pushes you away from the wind, which is why it’s better to get a “mismatched” pair…
Will you discuss this concept a little more? Is a mismatched set faster in all conditions? Faster for all riders? Do the same rules apply that everyone is discussing here for going to deep wheels in general? I am saving my pennies for my first set of “race wheels” (planning on Hed Jet 60’s) and while I strongly prefer the balanced aesthetic of a matching set (I know, I know, but my mind just really likes symmetry) I do not want to let my personal idiosyncrasies lead me to make a sub-optimal decision. Is a 6/9 combo that much better than a set of 60’s?