i need another wheelset and i was just gonna get some light rims but i have read that aerodynamics are more important.i read that light rims only accelerate faster.if this is true how should i compare wheelsets?
what is important?
1.so many millimeters of rim height
2.fewest spoke count
3.bladed spokes
4.other considerations that i haven't thought of
i weight 145 and 5'10" height.always ride alone.pride myself on climbing and live in a mountainous area.
there are lots of wheelsets on ebay now and i will spend from 200-300$.
also,i ride campy.when looking for wheels should i only buy wheels that are campy compatable or is there an easy conversion?
thanks in advance.

1st- aero is always better than lightweight up to the steepest climbs then light wheels are more beneficial.

2nd- low spoke count and bladed spokes do little to aid in aerodynamics. The rim is the deciding factor. For you to get a true aero benefit you need a rim with at least 36-38mm depth this would include wheels such as Zipp 303. Deeper section wheels such as Reynolds Stratus and LEW (46mm) and Hed Alps (51mm) and Zipp 404 (58mm) are even better. If I lived in a mountainous area I would choose either the Zipp 303s or the Reynolds Stratus DV. They are ultra light wheels that are aero too.

3rd- At your weight you will be able to ride nearly any wheel from a reputable builder. At your price range I don't know of too many options, certainly not any of the wheels posted above. You can find great deals on ebay but make sure you know what you are getting before you buy. You don't want to find out that your new to you wheel has a crack in the carbon fiber. Check the auctions for LEW composites wheels. They are super tough and very light wheels (1240 grams/pair). In fact, Reynolds purchased the LEW company and their new Stratus wheels are very similar. You can sometimes find a good deal on a set of LEWs which would give you an awesome set of climbing wheels.

4th- I would recommend that you look for a Campy rear wheel but you can use a Wheels Manufacturing conversion cassette on Shimano hubs. The cassettes work fine but you will have to spend an additional $150+ on a cassette whereas I think it would be better spend on more expensive wheels to begin with.

Hope that helps.

What speeds are you riding at? I would buy that "aero before weight" argument if you're riding a time trial at 25mph. Weight becomes a lot more important at lower speeds, especially in the mountains (thousands of feet of elevation gain).

What speeds are you riding at? I would buy that "aero before weight" argument if you're riding a time trial at 25mph. Weight becomes a lot more important at lower speeds, especially in the mountains (thousands of feet of elevation gain).
the only time i go 25 mph is downhill.i average around 17mph unless i climb more than a thousand feet and then i am even slower.

the only time i go 25 mph is downhill.i average around 17mph unless i climb more than a thousand feet and then i am even slower.

the only time i go 25 mph is downhill.i average around 17mph unless i climb more than a thousand feet and then i am even slower.


At your average riding speed, high dollar aero wheels won't make any measureable difference. Look for reputable brands (like Mavic, Campy) and only get a campy compatible wheel. I would avoid conversion cassettes, personally.

I'd have to disagree... Read this: http://www.bike.com/template.asp?date=6%2F5%2F2002&lsectionnumber=6

I'd have to disagree... Read this: http://www.bike.com/template.asp?date=6%2F5%2F2002&lsectionnumber=6


You're comparing pro level riding at 25-35 mph to a recreational rider who averages 17. Apples and oranges for sure.

If you're not racing (and the poster isn't), it's silly to worry about a few seconds on 2-hour ride.

(most of them anyway). Aero is not even a consideration for you, in all honesty. I'm about your same size and I used to do a lot of mountain riding before I moved to NYC (I was in Utah for about 11 years). Weight is EVERYTHING when climbing, and aero doesn't really matter all that much on the way down. (At our weight, fat guys will beat us downhill without even pedaling!) Seriously though, the only real reason I can think of to go with deeper rims is that they look cool. If your mountains are like the ones I used to ride in, that's actually a liability when the wind picks up. Nothing like having to fight a cross wind with wheels that seem to act like a sail...

Honestly though, if I were you (and I'm not because I'm a total Shimano man myself, but it doesn't really matter), I'd get the lightest, reliable set of wheels you can afford. Personally, I ride Ultegra hubs with Mavic MA3 rims, but had my budget been like yours, I'd have sprung for Open Pros.

One other thing, in retrospect, I'd never have gone with the 32 spoke wheels I have. Overkill at our weight. 28 or even 24 would probably be fine. Heck, my 28 spoke MTB wheels on my FS rig have taken a serious beating and still look brand new.

(most of them anyway). Aero is not even a consideration for you, in all honesty.
At 17mph, on level ground, 77% of a rider's power goes to overcoming aero drag. Of that 8.5% is the drag due to the wheels ( http://analyticcycling.com ). Deep section rims will reduce the wheel drag by 10% or 1% drag reduction overall.

I'm about your same size and I used to do a lot of mountain riding before I moved to NYC (I was in Utah for about 11 years). Weight is EVERYTHING when climbing, and aero doesn't really matter all that much on the way down.
I don't understand, what slows you down going downhill if not air drag?

the only real reason I can think of to go with deeper rims is that they look cool. If your mountains are like the ones I used to ride in, that's actually a liability when the wind picks up. Nothing like having to fight a cross wind with wheels that seem to act like a sail...
The benefit of aero rims is measurable and quantifiable. The articles by Kraig Willett do that or you can do it yourself at analyticcycling.com. Also, the benefit of deeper rims increases as the wind direction comes more from the side. As Kraig says, though, while the difference is quantifiable, whether that is significant is something only each individual can decide.

At 17mph, on level ground, 77% of a rider's power goes to overcoming aero drag. Of that 8.5% is the drag due to the wheels ( http://analyticcycling.com ). Deep section rims will reduce the wheel drag by 10% or 1% drag reduction overall.
Exactly my point. Who notices a theoretical 0.55% reduction in overall drag? You probably get better aerodynamic improvement by wearing shoe covers, which are a lot cheaper than new wheels. The original poster mentioned that he does a lot of mountain climbing at less than 17mph. Being able to accelerate on light wheels FAR outweighs the importance of wheel aerodynamics on that kind of riding, in my experience. (Unless you've got a long straight climb with a perfectly constant grade).
I don't understand, what slows you down going downhill if not air drag?
I don't really care about drag from my wheels when going downhill. In the mountains, I usually USE the wind drag to check my speed. But then, setting speed records isn't that high on my priority list, especially on a winding mountain road. As for what slows you down, sure it's almost all air drag, just not a lot of that is from the wheels. Certainly not enough for a "normal" person to ever notice. And light weight can certainly slow you down on the descents. 30-40 extra pounds of weight will overcome a lot of drag when you're flying down the mountain. I used to ride MTB's with a bunch of older, heavier guys and when we hit a long downhill stretch of pavement, my fastest pedaling couldn't keep up with their coasting. Of course, going UP the mountain was a different story...
The benefit of aero rims is measurable and quantifiable. The articles by Kraig Willett do that or you can do it yourself at analyticcycling.com. Also, the benefit of deeper rims increases as the wind direction comes more from the side. As Kraig says, though, while the difference is quantifiable, whether that is significant is something only each individual can decide.
Perhaps there are some benefits to deep rims when the wind comes at an angle, but if your rims are really deep (like some of the carbon models recommended above) staying on the road in a strong cross wind becomes a real problem. Kind of like the VW Vanagon I used to drive...

[QUOTE=Matno]Exactly my point. Who notices a theoretical 1% reduction in drag? You probably get better aerodynamic improvement by wearing shoe covers, which are a lot cheaper than new wheels.

If you can't notice a reduction in drag then how in the h@ll are you realistically going to notice a reduction of 50-100 or even 300 grams? Besides, the wheels I mentioned above are noted for their light weight as well as there aerodynamics. You show me a set of OP that can compare in weight and aerodynamics with Zipp 303, LEW or Reynolds Stratus DV. They simply can't. I really wonder if any of the people that have responded to this post have ever even seen let alone used a set of LEWs or Reynolds? I doubt they have. I have owned all but one of the wheelsets I listed in my post. Therefore I have first hand experience with them. Do you? Or do you simply post your opinions on equipment that you have never used?

As for the original post- Go ahead and get OPs for all I really care. Be ready for the inevitable click, click, click that the rim will surely develop after some miles. :p

Being able to accelerate on light wheels FAR outweighs the importance of wheel aerodynamics on that kind of riding, in my experience. (Unless you've got a long straight climb with a perfectly constant grade)...

Weight saved off the wheels makes no more difference in acceleration than weight saved anywhere else on the bike/rider. From http://www.biketechreview.com/archive/wheel_theory.htm
"So, what do all these numbers mean? It means that when evaluating wheel performance, wheel aerodynamics are the most important, distantly followed by wheel mass. Wheel inertia effects in all cases are so small that they are arguably insignificant.

"How can it be that wheel inertial forces are nearly insignificant, when the advertisements say that inertia is so important? Quite simply, inertial forces are a function of acceleration. In bike racing this peak acceleration is about .1 to .2 g’s and is generally only seen when beginning from an initial velocity of 0 (see criterium race data in Appendix D ). Furthermore, the 0.3kg/0.66lb difference in wheels, even if this mass is out at the rim, is so small compared to your body mass that the differences in wheel inertia will be unperceivable. Any difference in acceleration due to bicycle wheels that is claimed by your riding buddies is primarily due to cognitive dissonance, or the placebo effect (they paid a lot of money for the wheels so there must be some perceivable gain)."

Well said Asgelle. I'll admit that I am a Weight Weenie but I will also be the 1st to tell you that weight does not have as significant of an impact as aerodynamics.

I did my own test on a 28 mile loop which includes 3 good size and rather steep climbs. I used a regular "box" section rim (Mavic Ksyrium SL) and rode the course at 168 bpm. I then went back out two days later and rode the same course on the same bike at an average HR of 169 bpm. This time I used my Specialized Tri-spokes which are way heavier than the Ks.

Here are the results as copied from my training journal:
Sept 2002 ------- Colnago w/ Ksyrium SL wheels -- 1:27:19 Avg Heart rate 168 bpm.
Sept 2002 -------- Colnago w/ Carbon Tri-spoke wheels -- 1:25:18 Avg Heart rate 169 bpm. Total difference (-2:01)

For me it was clear to see that aerodynamics is a much bigger factor than weight.

I did my own test on a 28 mile loop which includes 3 good size and rather steep climbs. I used a regular "box" section rim (Mavic Ksyrium SL) and rode the course at 168 bpm. I then went back out two days later and rode the same course on the same bike at an average HR of 169 bpm. This time I used my Specialized Tri-spokes which are way heavier than the Ks.

Here are the results as copied from my training journal:
Sept 2002 ------- Colnago w/ Ksyrium SL wheels -- 1:27:19 Avg Heart rate 168 bpm.
Sept 2002 -------- Colnago w/ Carbon Tri-spoke wheels -- 1:25:18 Avg Heart rate 169 bpm. Total difference (-2:01)

For me it was clear to see that aerodynamics is a much bigger factor than weight.

No, this only shows the difference between 2 different rides. If you want to make a claim of which is superior, let's start with at least a couple dozen rides on each. From there, we'll determine a mean, std. deviation, etc, and see whether there is any significan difference.

Short of that, your observation is nothing more than anecdotal.

i need another wheelset and i was just gonna get some light rims but i have read that aerodynamics are more important.i read that light rims only accelerate faster.if this is true how should i compare wheelsets?
what is important?
1.so many millimeters of rim height
2.fewest spoke count
3.bladed spokes
4.other considerations that i haven't thought of
i weight 145 and 5'10" height.always ride alone.pride myself on climbing and live in a mountainous area.
there are lots of wheelsets on ebay now and i will spend from 200-300$.
also,i ride campy.when looking for wheels should i only buy wheels that are campy compatable or is there an easy conversion?
thanks in advance.
If you always ride alone, and if you don't look at your computer, you'll never know the difference until it comes time to replace a spoke, bearing, or true a wheel. You will notice a difference in comfort.

well.....i just built up some DT RR 1.1s to Dura-Ace (32h 3x...for a long tour this summer) for...120+140+40...$300. i'm sure if you dig around you could find a deal for Chorus around the same price.

[QUOTE=Matno] You show me a set of OP that can compare in weight and aerodynamics with Zipp 303, LEW or Reynolds Stratus DV.

Show me a set of any of those wheels in the $200-300 range this guy is looking for. I'd love to try some. As for OP's clicking, the number of people complaining about them on this board is far higher than I've seen in real life. I've never met anybody who uses them who didn't swear by them. Mechanical failure is uncommon for a 145lb rider.

Well said Asgelle. I'll admit that I am a Weight Weenie but I will also be the 1st to tell you that weight does not have as significant of an impact as aerodynamics.

I did my own test on a 28 mile loop which includes 3 good size and rather steep climbs. I used a regular "box" section rim (Mavic Ksyrium SL) and rode the course at 168 bpm. I then went back out two days later and rode the same course on the same bike at an average HR of 169 bpm. This time I used my Specialized Tri-spokes which are way heavier than the Ks.

Here are the results as copied from my training journal:
Sept 2002 ------- Colnago w/ Ksyrium SL wheels -- 1:27:19 Avg Heart rate 168 bpm.
Sept 2002 -------- Colnago w/ Carbon Tri-spoke wheels -- 1:25:18 Avg Heart rate 169 bpm. Total difference (-2:01)

For me it was clear to see that aerodynamics is a much bigger factor than weight.

For a test like this to have ANY significance, the wind conditions would have to be exactly the same for both rides, which is highly unlikely. Fitness levels from one day to the next can easily account for this much time difference. I ride the same route with same wheels and have times that vary by far more than that. For a test of this type to meaningfull, you'd have to measure both the direction and velocity of the wind and include valid compensation for any difference. The test would also have to be repeated MANY times.

Tests like yours almost always produce the expected result.

First of all, tests like mine have been conducted thousands of times by experts such as John Cobb and Steve Hed among others. Everytime they reveal the same results. Those results being that the Hed H3/Specialized tri-spoke wheel is 2 minutes faster than low profile "box" section rims over 40k. I'm sorry to contradict you oh great know it all C-40, but the facts are clear, aerodynamic wheels are faster than low profile, light weight wheels. End of discussion.


By the way dude, do you ever ride? 365 posts since Feb 2004? Get a life!

Amazing how some lose total sight of the original question asked. One other question for the aerodynamic gurus, sure guys like John Cobb who make a living pumping the huge benefits of aero wheels can quantify the aero mechanical benefits of such wheels, however, have they ever tried to quantify how much extra energy is wasted keeping such a wheeled bike on a straight course in heavy cross winded conditions?? Seems like guys like this specifically avoid this simple question a lot because it doesn't jive with their own agenda.

And by the way, trying to draw any meaningful conclusion from two separate training rides on two different days is asinine to say the least. Almost as asinine as talking up the benefits of Reynolds Stratus or Zipp 303 wheels to a guy looking for wheels in the $200-300 range, but not quite.

Amazing how some lose total sight of the original question asked. One other question for the aerodynamic gurus, sure guys like John Cobb who make a living pumping the huge benefits of aero wheels can quantify the aero mechanical benefits of such wheels, however, have they ever tried to quantify how much extra energy is wasted keeping such a wheeled bike on a straight course in heavy cross winded conditions?? Seems like guys like this specifically avoid this simple question a lot because it doesn't jive with their own agenda.

And by the way, trying to draw any meaningful conclusion from two separate training rides on two different days is asinine to say the least. Almost as asinine as talking up the benefits of Reynolds Stratus or Zipp 303 wheels to a guy looking for wheels in the $200-300 range, but not quite.

First, Kraig Willett makes no money pumping aero benefits. He performs wind tunnel testing at his own expense and tries to recoup some of the cost by selling the data. He has no vested interest in how the data comes out. And yes, he has estimated the energy needed to keep an aero wheel on course. In a cross wind, the side force is the same order of magnitude as the longitudinal force (the exact ratio can be calculated from the lift/drag ratio of the wheel and some trigonometry). But this is not the relevant value. In a steady cross wind, this force can be cancelled by leaning the rider's weight into the wind costing no power from the rider. In a fluctuating wind, the rider has to shift his weight to cancel the fluctuating side force but this depends on the changes in wind speed or direction not the absolute value of the wind. Since the magnitude of these shifts is moderate and the rate of change of the wind shift is slow, almost no energy is required to cancel these fluctuating side forces.

First of all, tests like mine have been conducted thousands of times by experts such as John Cobb and Steve Hed among others. Everytime they reveal the same results. Those results being that the Hed H3/Specialized tri-spoke wheel is 2 minutes faster than low profile "box" section rims over 40k. I'm sorry to contradict you oh great know it all C-40, but the facts are clear, aerodynamic wheels are faster than low profile, light weight wheels. End of discussion.


By the way dude, do you ever ride? 365 posts since Feb 2004? Get a life!

Maybe he posts here so much due to the fact that he has a lot of knowledge to share. Here's some of my knowledge. Don't rely on tests comparison tests when the person conducting the tests has a vested financial interest in the results, ie. it's no shocker that Steve Hed's tests show that Steve Hed's wheels are so damn much faster. Maybe the other tests have merit, but aren't those tests are conducted in a wind tunnel? If the original poster wants to ride inside a wind tunnel, or wants to ride flat time trials, or has $1,500-$2,500 to spend, NONE OF WHICH APPLY, he should use Steve's or any of the other impractical wheels you've been lucky enough to own.

Weight saved off the wheels makes no more difference in acceleration than weight saved anywhere else on the bike/rider

gotta review (or start to study for the first time) physics. Rotational Inertia DOES NOT behave exactly the same way as Linear inertia. Obviously the website you provided HAD NOT distinguished the difference. How do you lower the inertia of the wheel? They had not provide the method. Which inertia, rotational or linear? didnt say. Get 2 identical wheels, add 1 lb of weight onto the 1st wheel's rim, while adding 1lb to the 2nd wheel's hub. Spin them individually and feel the difference.

Make sure everyone please refer to some credible sources (or common sense, if u will) , not some magazine or bikeshop hearsay. Let there be Ksyrium SLs on the hills!

For the original question, i guess your best compromise is to get Mavic CXP33 laced to 28H Ultegra(Colorado Cyclist has them for $233). But Jack-of-all-trade simply is master of none. If you still got dropped behind after getting those pairs, oh well... :)

To add to this laundry list of posts. AE Bikes has the American Classic conversion cassette but it's for 10 sp. Do you ride 10? If so, they sell it for about $66, much cheaper than a Campy cassette.

If you're looking for a straight up Campy set, check ebay for a newer Centaur or Daytona hubset on good rims and spoke build. It'd be nice if a local builder could do this for you, though.

Good luck, and let us know how those $2000 Reynold wheels treat you. Oh, wait, sorry; from the other posts I thought you were a Cat 1 looking to shave off a few seconds in the next TT.



i need another wheelset and i was just gonna get some light rims but i have read that aerodynamics are more important.i read that light rims only accelerate faster.if this is true how should i compare wheelsets?
what is important?
1.so many millimeters of rim height
2.fewest spoke count
3.bladed spokes
4.other considerations that i haven't thought of
i weight 145 and 5'10" height.always ride alone.pride myself on climbing and live in a mountainous area.
there are lots of wheelsets on ebay now and i will spend from 200-300$.
also,i ride campy.when looking for wheels should i only buy wheels that are campy compatable or is there an easy conversion?
thanks in advance.

gotta review (or start to study for the first time) physics. Rotational Inertia DOES NOT behave exactly the same way as Linear inertia. Obviously the website you provided HAD NOT distinguished the difference.
Is this a joke? Did you even read the article? If you had read the article you would see that he has explicit terms for linear and rotational inertia and does, in fact, distinguish between the effects. He derives his model from first pricipals (F=ma) and this model has been validated against actual instrumented riders.

How do you lower the inertia of the wheel? They had not provide the method.
Since these are model calculations, one doesn't need to specify the method of reducing moment of inertia. Run the model with one moment of inertia, run it again with a different one, see the effect on speed or power. Repeat for different wheel masses, drag coefficients, etc.
Which inertia, rotational or linear? didnt say.
From the context it is clear the wheel inertia refers to rotational inertia, linear inertia is dealt with in the treatment of wheel mass.
Get 2 identical wheels, add 1 lb of weight onto the 1st wheel's rim, while adding 1lb to the 2nd wheel's hub. Spin them individually and feel the difference.
if you've ever tried spinning a wheel from 0 to 20 mph on a workstand, you would know it takes almost no effort. Once spinning, it takes almost no power to maintain the wheel at 20 mph. The difference in power required to spin a wheel with half the moment of inertia of another is less than 1/2 Watt. I seriously doubt anyone could feel this difference.
Make sure everyone please refer to some credible sources (or common sense, if u will) , not some magazine or bikeshop hearsay. Let there be Ksyrium SLs on the hills!
I feel Kraig Willett is a credible source given that he receives no funding from the bike industry, and presents the full derivation of his model and his actual data, but if you have your doubts, go to http://www.analyticcycling.com and run the calculations for yourself. I have and the results are as stated,

I should have read through the article rather than skimming through.

if you've ever tried spinning a wheel from 0 to 20 mph on a workstand, you would know it takes almost no effort. Once spinning, it takes almost no power to maintain the wheel at 20 mph. The difference in power required to spin a wheel with half the moment of inertia of another is less than 1/2 Watt. I seriously doubt anyone could feel this difference.

Statement is only true when the wheel is spinning freely without friction. Work is needed to overcome the road friction.But it applies for all wheels, so I'll take it for granted. But there is a discrepancy in your 1/2 watt calculation. It turns out to be 50% of power difference, not 1/2 watt. I would consider 50% less power a significant difference. Also total work done to spin the wheels are dependent on distance travelled. So although average instantaneous power can be minimal, over time it adds up, and it is not directly related to the bike's translational velocity.

Another thing I noticed from Mr.Willett's article that he described the uphill portions as "TT similar". IF that is the case, This experiment would be conducted at speed that will favor an aerodynamic wheel. I am would be a little doubtful at lower speeds, aerodynamics will still play the same importance. And in case of a commuter like me, it may not work its big miracle on me that well.

One problem that has been bothering automotive engineers when designing race cars is the problem of unpredictable turbulence presence when in racing situation. Frequently they have to measure the wind conditions at the circuit before doing aerodynamic adjustments on the race car. In a tight peloton, this is even more of a problem. Mr.Willet's data has been collected under a controlled condition. It is very possible that the major aerodynamic benefit of a deep-secton wheel in a "wind-tunnel like" condition will be negated by less-than-ideal airflow problems.

I would not decline the benefit of an aero wheel can offer, but the benefit can be very conditonal, while the benefit of a lighter rim is perfectly repeatable and constant regardless of any situations.

No flames, let me know what you guys think.

I should have read through the article rather than skimming through.
Statement is only true when the wheel is spinning freely without friction. Work is needed to overcome the road friction.But it applies for all wheels, so I'll take it for granted.
You don't have to take it for granted, Willett includes it explicitly in the rolling resistance term.
But there is a discrepancy in your 1/2 watt calculation. It turns out to be 50% of power difference, not 1/2 watt. I would consider 50% less power a significant difference.
From Willett's article, Power for training ride = 193.66W, power with 50% lower front wheel inertia=193.63 (0.03W lower), 50% lower rear wheel inertia=193.62 (0.04W) lower). For uphill portion of the training ride Power=237.2W, 50% lower front wheel inertia=237.19W (0.01 lower) 50% lower rear wheele inertia=237.18W (0.02W lower). So my 0.5W was a gross exageration, I'm sorry, the true loss is much less.
Also total work done to spin the wheels are dependent on distance travelled.
Work is not power times distance but powerXtime.
So although average instantaneous power can be minimal, over time it adds up, ...
Yes, in fact work equals power times time; but if you have lower power, you'll have lower work. Also riders are not work limited but power limited. There's a thorough discussion of this at www.cyclingpeakssoftware.com.
...and it is not directly related to the bike's translational velocity.
Well, yes it is. Power to overcome aero drag is proportional to the velocity cubed, power to overcome rotational inertia, gravity and rolling resistance is proportional to velocity to the first power.
Another thing I noticed from Mr.Willett's article that he described the uphill portions as "TT similar". IF that is the case, This experiment would be conducted at speed that will favor an aerodynamic wheel. I am would be a little doubtful at lower speeds, aerodynamics will still play the same importance. And in case of a commuter like me, it may not work its big miracle on me that well.
The fraction of rider power needed to overcome drag does depend on speed (it also depends on slope of the road, surface smoothness, rider size and weight, and other parameters) but if you do the calculations at analyticcycling.com, you'll find the time saved by reducing drag is greater for slower riders than faster ones. Note I'm referring to time savings. This is mainly because the slower rider is riding longer and so has more time to benefit from the increased speed.
One problem that has been bothering automotive engineers when designing race cars is the problem of unpredictable turbulence presence when in racing situation. Frequently they have to measure the wind conditions at the circuit before doing aerodynamic adjustments on the race car.
This is because cars are designed to produce downforce and the design is based on undisturbed flow (the flow is already fully turbulent). This has nothing to do with bicycles.
In a tight peloton, this is even more of a problem.
The peleton wil shield a rider from the wind making the apparent wind speed les than for a rider alone. Other than the decreas in wind speed, the peleton has no effect.
Mr.Willet's data has been collected under a controlled condition. It is very possible that the major aerodynamic benefit of a deep-secton wheel in a "wind-tunnel like" condition will be negated by less-than-ideal airflow problems.
I have to repeat, "Did you read the article?" Willett's final data set is taken from a rider in the middle of a Pro,1,2 Crit and the model works equally well for that data.
I would not decline the benefit of an aero wheel can offer, but the benefit can be very conditonal, while the benefit of a lighter rim is perfectly repeatable and constant regardless of any situations.

No flames, let me know what you guys think.
The benefit of reduced drag depends on knowing the environmental wind and the benefit from lower weight depends on knowing the grade of the road. There is uncertainty in both these quantities; though I grant you the there will be more uncertainty in the wind. However the 4-10:1 benefit of reduced drag over reduced weight is more than enough to overcome any uncertainty in the wind in deciding which will produce the larger benefit.

Getting dizzy here. Is this the bottom line(s): if you had to choose between aero vs non-aero, go aero.

if you had to choose between an aero/heavier wheel vs a non-aero/lighter wheel, go heavier/aero.

if you can get an aero and light wheel, it's the best of both worlds.

or do i need to have another cup of coffee to wake up?

Kerry and I had an interesting discussion on the wheel weight importance issue. I provided several links to a super high level discussion by some of the biggest brains in the industry who beat each other over the head with physics models, tons of experience and years of scientific testing by race teams. The result- about 50-50 on either side of the question, with people I respect on either side. So don't be too sure of yourself no matter what side you are on, because somebody smarter and more experienced than you has the other side and the proof to back it up.

But general notions which seem safe:

1. For flat to somewhat rolling solo rides at speed, TT's and high speed competitive riding- aero is king, assuming steady state riding (not tons of accelerations and speed changes).

2. On the big hills, weight is king. Light wheels and big mountains go together like milk and cookies. On the steeps, even bottom line racer$ will risk angering sponsors to ride restickered lighter wheels.

3. For aero, deep rims matter the most unless you pony up for a tri-spoke wheel or a rear disk. Spokes and frames ect make a much smaller difference- but over 40K if the TT race is real close they may make a difference. Plus they look neat!

4. Truly aero wheels are a bit scary in serious crosswinds.

5. The wheel weight importance issue attracts almost as many bike nerds as the Shimano vs Campy debate (which everyone knows Campy wins-- heh just kidding Shimano partisans, put down your pitchforks and torches).

First of all, tests like mine have been conducted thousands of times by experts such as John Cobb and Steve Hed among others. Everytime they reveal the same results. Those results being that the Hed H3/Specialized tri-spoke wheel is 2 minutes faster than low profile "box" section rims over 40k. I'm sorry to contradict you oh great know it all C-40, but the facts are clear, aerodynamic wheels are faster than low profile, light weight wheels. End of discussion.


By the way dude, do you ever ride? 365 posts since Feb 2004? Get a life!

You won't gain a lot of repsect by making offensive posts.

You could use some education (my degree is in mechanical engineering). If you had any scientific background, you would realize how invalid your 2-ride test is. I would never argue that aero wheels aren't faster, but if you would take the time to read valid tests, you would also note that the benefits increase dramatically as speed increases. Recreational riders who are not competing against anyone and avergaing 17 mph will derive far less benefit from a pricey aero wheel. Certainly not 2 minutes and a 25 ride.

As for a life, I have one but it doesn't include working, so I can ride anytime I want.

Kerry and I had an interesting discussion on the wheel weight importance issue. I provided several links to a super high level discussion by some of the biggest brains in the industry who beat each other over the head with physics models, tons of experience and years of scientific testing by race teams. The result- about 50-50 on either side of the question, with people I respect on either side. So don't be too sure of yourself no matter what side you are on, because somebody smarter and more experienced than you has the other side and the proof to back it up.
Could you post some of these links. I ask because all the information I've seen has indicated that except for steep climbs aero trumps weight. I'm not disputing what you say, I'd just like to see the counter argument.
... you would also note that the benefits increase dramatically as speed increases. Recreational riders who are not competing against anyone and avergaing 17 mph will derive far less benefit from a pricey aero wheel. Certainly not 2 minutes and a 25 ride.
It depends on how you define benefit. The reduction in power is greater for the faster rider, but the reduction in time is larger for the slower. As I said above this is mainly because the slower rider is out longer. For example, on a 25 mile flat course comparing aero and standard wheels, a 25 mph rider saves 21.3 W, increases speed 0.84 mph, and saves 1.95 minutes. A 17mph rider saves 6.7W, increases speed 0.54 mph, and saves 2.5 min. (all numbers are approximate within the accuracy of the assumptions and the model).

Could you post some of these links. I ask because all the information I've seen has indicated that except for steep climbs aero trumps weight. I'm not disputing what you say, I'd just like to see the counter argument.

No I am talking about the importance of wheel weight versus overall weight and the moment of inertia debate.

I think as a general principal, the aero aspects of the wheel are pretty widely accepted as being key. The differences lie in how steep and long the climbing must be before it makes a difference. Additionally, don't forget the situation with tons of accellerations and speed changes, which may be another situation where the lighter wheel is superior.

Of course, light and aero like the delightful Reynolds carbon wheels is kind of the best of both worlds (except for your budget! ;) )

No I am talking about the importance of wheel weight versus overall weight and the moment of inertia debate.
Got it, thanks. Sorry about the confusion.

Could you post some of these links. I ask because all the information I've seen has indicated that except for steep climbs aero trumps weight. I'm not disputing what you say, I'd just like to see the counter argument.

It depends on how you define benefit. The reduction in power is greater for the faster rider, but the reduction in time is larger for the slower. As I said above this is mainly because the slower rider is out longer. For example, on a 25 mile flat course comparing aero and standard wheels, a 25 mph rider saves 21.3 W, increases speed 0.84 mph, and saves 1.95 minutes. A 17mph rider saves 6.7W, increases speed 0.54 mph, and saves 2.5 min. (all numbers are approximate within the accuracy of the assumptions and the model).

I'm curious who's computer program you're using and the specs & price of these hypothetical (?) aero wheels. I think you've proved my point, though; the power benefit increases with speed. I don't think the 2.5 minutes saved by the slower rider would be much consolation for the poor guy who finished "only" 27.5 minutes behind instead of 30.

I'm curious who's computer program you're using and the specs & price of these hypothetical (?) aero wheels. I think you've proved my point, though; the power benefit increases with speed. I don't think the 2.5 minutes saved by the slower rider would be must consolation for the poor guy who finished "only" 27.5 minutes behind instead of 30.
I use the model at www.analyticcycling.com . This is the one which has been validated against instrumented riders and published in the peer reviewed literature. There are no wheels. as you say they are hypothetical. I can find wheels which match the parameters, but what's the point, we're only looking at the effect of wheel choice. As to proving your point. I can't agree, One could look at power saved, increased speed, or time saved. The first two favor the faster rider; the last, the slower. Which wheel provides more benefit depends on a person's choice of metric and since that depends on the individual, I can't say which is better a priori. I can say that for one choice, aero wheels benefit a slower rider more than a faster one. As to whether the 2.5 minutes savings is significant, I can't say. Again that depends on the individual, but I can say that the 17 mph rider saves 2.5 min. and the 25 mph rider saves 2, and that 2.5 is bigger than 2.

Work is not power times distance but powerXtime.
This is not true. Work is Force x distance ( distance=velocity x time). Power is either Force x Velocity, dV/dT or torque x angular speed. I cannot derive your equation out form these. Longer the distance the rider travels, longer the time. You can state that ther's a constant ratio between velocity and time over a fixed distance, but this is not certainly true when realistically, rider speed varies. I am not trying to adhere to this law strictly, since it involves a lot of integrations. So Power and Work output varies on velocity, while velocity depends on time. There is simply no fixed average [ower output over a fixed ride time, so gain by aerodynamics is not constant.

Yes, in fact work equals power times time; but if you have lower power, you'll have lower work. Also riders are not work limited but power limited.
True. I see your point of benefits from aero wheels, but as i have stated, the gains varies too much, so the only "surefire" way to reduce work done (and therefore power) against drag (rolling resistance + aero drag) is a lighter rim.

Well, yes it is. Power to overcome aero drag is proportional to the velocity cubed, power to overcome rotational inertia, gravity and rolling resistance is proportional to velocity to the first power.
I should have worded my statement a little better to avoid misunderstanding. You are true in both statements, and that is the fact too. However aerodynamic drag also depends on the frontal area of the wheel. Lower spoke counts will reduce the frontal area, while deep-section rims reduce turbulent after the trailing edge of the rims. But compare the rolling friction with the aero drag, we may not see a very significant difference. I may also go as far as stating rolling frictional force will be bigger in magnitude. In 20mph, 70% of the rider's power output is used to overcome aero drag. True. But a good portion of that drag comes from the rider's own body and the frame. Drag from a couple more spokes and shallow rims are also relatively small, just like what you stated about rolling inertia and total linear inertia.

It's good to have some healthy conversation going on to press me back to my physics textbook...

If you don't know that power is the rate of doing work (P=W/t, or W=P*t) then I'm afraid we really have nothing more to say to each other. If this was a troll, good job, but you just overplayed your hand.