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Bladed spokes? How much difference?(41 posts)

Bladed spokes? How much difference?bill
Feb 11, 2003 2:23 PM
I know this is area covered before, but I wasn't paying attention so sue me.
I'm considering Am Classic 420's -- seems a nice, reasonably aero, light for aero, well-made wheelset. Comes with bladed or conventional spokes. The guy at AmClassic did not push the bladed spokes, saying that he didn't buy into their aero effects, and he didn't think that I would need te additional strength.
What do you all think?
my take on thisDougSloan
Feb 11, 2003 2:37 PM
On long descents around here, I have a pretty good feel for speeds, having done them hundreds of times.

I swear that low count bladed spokes are faster, and it seems to matter more than rim shape. My Nucleons feel far faster than my standard 32 spoke Open Pros, and about the same as my Zipp 303's. The Nukes are low count, bladed spokes.

I have no scientific data, and not even some sound reasoning, but purely anecdotal observations. Nonetheless, I'll rely on my observations over someone else's theory or tests.

Doug
my take on thisaltidude
Feb 11, 2003 3:32 PM
Out of all the components of a rider and bicycle that create drag, and there are many for sure, do you really think having fewer bladed spokes increases your speed to the point of being able to actually feel the difference? your body and frame create so much more drag and turbulance than some tiny spokes on your wheels, I find it almost impossible to imagine that anyone could actually feel an aerodynamic difference simply by lowering their spoke count or going with bladed spokes. A low spoke count, deep dish wheel will supposedly save a person a couple seconds per kilometer in your typical time trial application. Are you saying you can actually feel a real difference in speed on a descent if it causes you to be a mere second or two faster per each kilometer of descent? That seems very hard to believe just from a pure common sense logic standpoint.
I'll do an experimentDougSloan
Feb 11, 2003 3:52 PM
How about I go and do the same descent multiple times, changing only the wheels? I'll record both elapsed time and top speed. I'll begin at 20 mph even, then move to the same tuck each time, controlling as close as I can. We can even run a stats analysis on it the data and see if it's significant.

This might take a while, but I'll eventually do it and report back. The bitch about it is that I have to climb the darn hill all those times! I have in mind a 1.5 mile approx. 10% descent that I've hit 55 mph on.

Keep in mind that the upper spokes are moving with respect to the wind at twice the road speed, or 110 mph on this hill. Of course, effects will be exponentially smaller at lower speeds.

Any suggestions?

Doug
I'll do an experimentaltidude
Feb 11, 2003 4:41 PM
Yes, and your upper rim and tire are also moving at twice that road speed, and they have way more surface area than any of your spokes, but they remain unchanged unless you are talking about a completely different tire and wheel setup.

Lets put it another way, suppose you ridgidly attached 12 spokes in an upright position to the top of your shoulders, 6 on each shoulder and then you dove out of an airplane. Do you honestly think your descent speed would be significantly sfaster (ie have significantly less air drag) by then jumping out of the plane a second time with a total of only 6 spokes on your body, 3 per shoulder? No friggin way, and you don't need a degree in aerodynamics or physics to understand this. It's all placebo affect and marketing hype by component makers. You know you are on a different lower spoke count wheel and you imagine being loads faster. in reality these ultralight and low spoke count wheels may save you some seconds in a time trial, but they are not going to make you move through open air miles per hour faster to the point that descents feel visibly faster.
I'll do an experiment--? Apples-to-applesWheelwrite
Feb 11, 2003 5:05 PM
Ok, the airplane theory doesn't work because you're not comparing apples-to-apples. First of all you're comparing static (non-rotating) spokes on your shoulder jumping out of an airplane with only a gravitational pull, i.e. terminal velocity--once you hit it, you can't fall any faster vs. a rotating mass at ground level (completely different gravitational pull) being propelled at motion by your body and a thing called inertia.

I think you just flunked Physics 101 and the E=MC2 man just rolled over in his grave. You need to do some more research to back up your claims and no--it's not a marketing ploy. Just ask Lance and Chris why he/they prefer(s) Hed wheels when climbing the Alpe D'.

Over and out.

8^)
Because they are paid to. Simple. nmRimfired
Feb 12, 2003 9:37 AM
not so simpleDougSloan
Feb 12, 2003 11:05 AM
Some pros come out of pocket to buy their own fancy wheels that are not from their sponsors, ADA's, for example.
Because they are paid to. Simple. Not really!Wheelwrite
Feb 12, 2003 3:06 PM
No that's not entirely true. Lance and USPS, although under contract with Bontrager are riding their wheels. However, you'll see him riding Heds in the Alps with Bontrager decals on them. Inasmuch the same way (up until a few years ago) Lance was riding a Litespeed Timetrial frame with Trek decals and USPS colors until Trek got their act together and built what Lance and the boys now ride. When you're the top dog, you can pretty much ride what you want and have it "decal'd" to look like the sponsor's bike. Same way with Tyler Hamilton and CSC-Tiscali last year. Tyler, although his bike was "decal'd" like a Look KG-381, was riding a custom-built American Made carbon-fiber frame. In fact I'm told that CSC is riding the same frames this year, although they have a contract with Cervelo.
But then againRimfired
Feb 13, 2003 7:46 AM
Lance also used to ride with those boat-anchor pedals for a long time, just because he liked them. No one claims they are faster/lighter of themselves.

I think it just all goes to show that pros ride stuff they like - dependability/feel etc is just as big a factor as aero/lightweight.

If it was all as clear as people make out - they's all be on one wheel type/design for given events/conditions, would they not?

Re contracts and frames etc. We see a percentage of the backstage wrangling over contracts/money that goes on - you can't take it a face value.
I'll do an experimentaltidude
Feb 11, 2003 4:44 PM
The only way your experiment would be legit was in a pure blind test, ie you are put on a bike and you honestly do not know which wheels are on it and you do not look down at your wheels to see what you are running. Other than that, a test where you know each time what you are riding is as invalid as those who test frames and report the same placebo affects. The $4000 had to ride great, why, because it cost $4000 that's why.
Assuming that...PsyDoc
Feb 12, 2003 5:22 AM
...you exert as much experimental control as possible and do multiple runs (say 10 with each wheelset?), I think your results would be o.k. and specific to your body proportions, tuck style, etc. One possible improvement would be to have a friend do the same ride on the same day as your friend would be less suspectible to any type of experimenter expectancy effects (i.e., unconscious influences that could impact the results). Ideally, you would alternate runs to take into account time of day, wind, temp, etc. If you want, you can send me the data when you are finished and I could analyze them a few different ways with a statistical program called SPSS.
experiment issuesDougSloan
Feb 12, 2003 1:44 PM
Do you think using aerobars for a more fixed upper body position would be better?

Also, better to start from a dead stop and just gravity roll (but then we have frictional and inertial issues), or from an equal higher speed, like 20 mph, which might yield higher (more signficant?) speeds?

Don't know any way to do this blind. I'll just have to control the best I can. In any event, I'll fully describe the circumstances.

With varying top speeds around 50 mph and 10 trials on each wheel, what speed differences will be statistically significant (or is it better I don't know this ahead of time)?

Doug
experiment issuesPsyDoc
Feb 13, 2003 8:08 AM
Aerobars...did not really think of those. As long as you consciously keep your position constant (or as close as you can), then I do not think it would matter significantly. I think you would have better generalizability not using the aerobars, but others could argue differently.

Starting from a dead stop and letting gravity takes its course would be better, in my opinion, than from a rolling start.

How could you do this blind? Deceive your participants. If you can find a couple of your friends that you trust, then they could be willing "victims." Mislead them. Tell them that you are noticing some vibration at high speed and you want to know if they can detect it. You seem pretty anal-retentive, so when they see the elaborateness of the test (i.e., starting from a dead stop, etc) they will not think anything of it. Calling you anal was a compliment.

The speed differences are not as important as the variance/standard deviation. For example, you could have a large speed difference between two wheelsets, but the standard deviations are also large; hence, no significant difference. Or, you could have speed differences that do not "look" like they should be significantly different, but the standard deviations are small; hence, a significant difference. For example, a mean of 4.03 is statistically different from a mean of 4.14 due to small standard deviations.
my take on this--I concur with Doug!Wheelwrite
Feb 11, 2003 3:32 PM
Just can't explain it. But it works. I rode my son's bladed Xero's from Supergo for a few rides and comparing them to my 32-hole CXP-33's with 105 hubs, I found I was riding faster and the wheels seemed to split the headwinds better, too with no appreciable feeling of being buffeted by a cross wind either. Albeit, they were stiffer, though, so maybe that's the trade off.

Good Luck

8^(>)
I concur with Doug also! Never thought I wouldekdave
Feb 11, 2003 3:51 PM
I have a set of 32h open pros and some Rolf sestrieres (24/20 hole) the rolfs dont have a deep rim (22mm), but do have low count. I can tell you 100 sure I notice the higher speeds on downhills. I didnt buy into low count either till I tried it.

Fastest wheels I have tried (fastest feeling) were some 20 hole (f and r) bladed 30mm deep wheels.

I swear it doesnt make sense standing still, but maybe its when the spokes are moving through the air (circularly) very quickly that the drag adds up.

I even have the same tires on my wheels - I swear I cant tell you why its faster, it just really is.
my take on this--I concur with Doug!altidude
Feb 11, 2003 3:53 PM
If what you guys claim is true, then any person on a solo breakaway or a TT without an aero wheel would have no chance against similiar level competition running so called aero wheels. Yet each and every week in this country and others around the world, guys riding conventional, high spoke count wheels do fine in such events if they have the engine. what you guys claim about feeling lots faster sounds a lot like placebo affect knowing you are on a different wheel and little more. Spokes create so little drag compared to you body's position, your frame and your overall wheel profile that to try to claim by reducing spoke counts you are suddenly 5 or even 3 miles an hour faster is very difficult to believe IMO. If this were the case, no guy on a breakaway in the TDf with a non aero wheel would ever stand a chance at outrunning the peleton, but almost every year it happens in a couple stages. Wheel aerodynamics may increase your speed very marginally in a pure descent or TT application, but they certainly are not going to make you loads faster IMO. It would be comparable to me claiming that I just shaved all the hair off my right forearm, now I'm a lot faster. nope.
my take on this--I concur with Doug!--againWheelwrite
Feb 11, 2003 4:18 PM
I understand your theory 100%. And yes it may be just a placebo effect. But the fact remains--and I have been a cyclist for 29+ years and have ridden all sorts of wheels--that wheels do, indeed, make a difference. I'm not a Physicist so I can't explain the mathematics behind velocity, drag coefficients, and centrifugal forces when it comes to figuring out what makes them faster. But I do have to beg the question, if it's not that big of a deal, then why are there so many lightweight, minute-numbered, bladed-spoked wheels out in the marketplace and why are so many of them being ridden in the peoloton?

Does Salvodelli suffer from the same placebo? Or is it a marketing ploy by Shimano, Campy, Hed, Zipp and all those other Eurpean manufacturers?

Hey, I like 'em! The coolness factor is way up there. I wanna be like Lance (LOL)!

8^(>)
counterintuitive?DougSloan
Feb 11, 2003 4:20 PM
Many times, and I've been shocked before, these aero issues can be counterintuitive. Check some of the findings at: http://www.analyticcycling.com/RiderAeroStudy.html

For example, would you think that having 2 bottles on your bike frame in conventional positions is more aero than bottles behind the saddle, or a Camelbak? Seems weird.

I've read, but can't find it now, that about half the drag from wheels comes from spokes and half from the rims. Aero and fewer spokes would help.

A streamlined object, like a spoke or a frame tube, has 1/10th the drag of a round one. Now, flat or blades spokes are not teardrop shaped, but much closer than round.

A test is the only way to go. No amount of rationalizing will answer the question. Rationalizing got us a flat earth for thousands of years, right?

Doug
counterintuitive?altidude
Feb 11, 2003 4:28 PM
It doesn't matter if half the drag from wheels comes from spokes. The drag created by your spokes is probably on a conservative order 50 times less than the drag created by your body and its position in the air. Look at the total frontal surface area of all your spokes comapared to the surface area of your body. there is simply no way by reducing such a measly component as spoke count that you somehow by magic all of a sudden ride lots faster. IOt would literally be like me claiming I just shaved the hair off my right forearm, now i'm a lot more aerodynamic, bulldookey, no way, impossible. Talk to any aerodynamics expert and they'll tell you your body on a bike creates on a geometric scale more air disturbance and resistance than any component on your bike. Spokes play such a tiny role in air drag relative to the complete rider and bike package there is no way you will become loads faster by simply reducing your spoke count. You might gain some seconds in a time trial, but you are not suddenly gonna go from riding 20 mph to 22 mph unless you have somehow changed your engines output.
Well, you just rationalizedRimfired
Feb 12, 2003 9:42 AM
that tear-drop shaped spokes are the most efficient shape.

So why don't we have them, if every one is so keen on their experiments, modelling and aero wheelsets, and all this is to easily testable?
my take on this--I concur with Doug!--againWheelwrite
Feb 11, 2003 4:43 PM
I understand your theory 100%. And yes it may be just a placebo effect. But the fact remains--and I have been a cyclist for 29+ years and have ridden all sorts of wheels--that wheels do, indeed, make a difference. I'm not a Physicist so I can't explain the mathematics behind velocity, drag coefficients, and centrifugal forces when it comes to figuring out what makes them faster. But I do have to beg the question, if it's not that big of a deal, then why are there so many lightweight, minute-numbered, bladed-spoked wheels out in the marketplace and why are so many of them being ridden in the peoloton?

Does Salvodelli suffer from the same placebo? Or is it a marketing ploy by Shimano, Campy, Hed, Zipp and all those other Eurpean manufacturers?

Hey, I like 'em! The coolness factor is way up there. I wanna be like Lance (LOL)!

8^(>)
my take on this--I concur with Doug!--again--oops NM. Mea culpaWheelwrite
Feb 11, 2003 4:45 PM
re: Bladed spokes? How much difference?Wheelwrite
Feb 11, 2003 5:12 PM
Hey, sorry! And you thought you were going to get some great advice instead of opening a Pandora's Box.

I think the key here is fewer spokes/Aero rim vs. conventional. American Classic and Bill Shook have been around for a very long time and if he says the 420's with non-bladed spokes are OK and you're not a "Clydesdale" then by all means go for it!

Remember...opinions are like a_ _ h _ _ _s! Everybody's got one! (ROFL)
there really is a differance here is how you can tell.........the bull
Feb 11, 2003 6:54 PM
put you bike in a stand and move the pedal in high gear as fast as you can.
then get you face and feel the wind moving off the spokes
try a more areo wheel...less wind huh?
now imagine the turbulance this is creating on a moving bike
I agree with doug
if you dont then move the pedal around real quick
then stick you nose in the spokes as the wheel is moving
feel the resistance now?
there really is a differance here is how you can tell.........mghwk
Feb 12, 2003 12:00 AM
The previous illustration was a good one... Spoke aerodynamics are very important. The frontal area of each spoke is small, but the speeds are high and there is the multiplicative effect of the spokes presenting their frontal areas almost 24,000 times each mile for a 32 spoke wheel at twice the speed of the bike. Its a big deal, or I could pedal lots faster on my rollers.
are bladed spokes dangerous?tarwheel
Feb 12, 2003 4:50 AM
Aside from the aerodynamics issues, I would be afraid to ride a bike with bladed spokes. It seems like if you ever accidently jabbed a finger in the wheel, off it would go. Now, admittedly, it's not a smart idea to ever stick a finger in any spinning wheel. But I've known cyclists who have accidently done it while while cleaning a tire or a closing a brake release.
This whole topic has 2 very curious aspectsscorpionking
Feb 12, 2003 5:38 AM
I'd be real interested in knowing how much faster those who think low spoke count wheels help them so much are actually icreasing their real speed? Doug claims he can feel the difference on descents. In terms of say miles per hour Doug how much faster do you think the lower spoke count wheel is helping you move? If you can feel the difference, logic would tell me that you are talking about a several mile per hour difference. I doubt you could consciously feel or perceive any noticeable difference between say a 48 mph descent versus a 49 or 50 mph descent. So I can only assume you are talking about something like a 5-10 mph difference. A 5 mph difference would be a 10% increase in speed based upon a 50 mph descent, a huge difference in speed by any rational account. Are you saying the low spoke count wheels are making you that much faster all other things being equal or are you saying that you can actively perceive a big difference in your descent speed when the difference is only say 1-2 mph or in other words a 50 mph descent feels lots faster than a 49 or 48 mph descent? It is for thses reasons I too really doubt that low spoke count wheels are making your bike go much faster. I think its all in your head. Low spoke count wheels are not going to increase your speed by 10% on a descent, certainly not Campy Neutrons which have 24F and 28R versus a conventional 32 or even 36 spoke wheel. No wheelchange in existence will make you descend 10% faster all other things being equal. On the other hand, if your change in speed is only say 1 mph, then you are asking me to believe that you can through your perception of your bike feel a big recognizable difference between a 49 mph versus a 50 mph descent, I find that even harder to fathom. I think it's all imagination and in your heads. I know several CAT II level racers who have said in all honesty that regardless of which wheelset they show up with at a race, their performance and results are invariably the same. You will almost never find a serious categoried racer who claims that wheel changes or frame changes or other component changes make big differences in their speed or results. These claims are almost always invariably made by recreational riders who just purchased a product or are the claims of the component makers themselves.
Exactly rightBipedZed
Feb 12, 2003 6:02 AM
"You will almost never find a serious categoried racer who claims that wheel changes or frame changes or other component changes make big differences in their speed or results. These claims are almost always invariably made by recreational riders who just purchased a product or are the claims of the component makers themselves."

I used to purchase all sorts of trick/lightweight wheels and components in the hopes of some performance gain. Now that I've been seriously racing/training for 3 years and about to upgrade to Cat 2 I've realized equipment doesn't make you faster. I've had some of my best results on my relatively heavy training wheels.

Get your fitness up and you'll realize the gear isn't holding you back.
oh, so that's why...DougSloan
Feb 12, 2003 7:19 AM
That's why I see Lance riding critical stages of the Tour, like timetrials and mountain finishes, on his 32 spoke Open Pros with 14 gauge spokes. Makes sense to me now. Oh, well, I guess I was under the naive false impression that he was a "serious categoried racer." My mistake. I suppose he has to ride what his sponsors tell him to, though, but if it were his choice he'd pick the heavy, standard wheels over the so-called "faster" wheels. Maybe if he just got his "fitness up" he'd realize that he didn't need those chi-chi wheels. :-)

Doug
Well, at Lance's level, in the TdF, aOldEdScott
Feb 12, 2003 7:58 AM
couple of seconds can be critical over a 2000 mile race. Even a miniscule advantage he might get from those chi chi wheels is magnified out of all proportion over that many miles and that many days.

That said, I have 'felt' faster on low-count bladed spokes myself. Whether I was or not, I don't know and tend to doubt. But I for one would be interested to hear the results of the experiment you propose. We can flap our jaws all day about it, but something empirical would be nice.
here's some dataDougSloan
Feb 12, 2003 8:14 AM
From Analytic Cycling:

Wheel Aerodynamics

A paper by D. I. Greenwell, et. al., entitled "Aerodynamic Characteristics of Low-Drag Bicycle Wheels", Aeronautical J., Vol. 99, No. 983, Mar. 1995, pp.109-120, has a good discussion of the aerodynamics of bicycle wheels. Conclusions by Greenwell et al:

The total drag of the wheels is in the range of 10% to 15% of the total drag on a bike. Drag improvements between wheels can reduce this by 25%, or 2% to 3% of the total drag.

Axial drag forces are difficult to measure precisely. Most single valued measurements should be suspect.
Deep section aero wheels are better than a conventional 36 spoke wheel and are all about the same within the limits of measurement. Disk wheels are better yet. (Don't run a disk in front if there is any chance of wind.)

The rotational drag on a wheel does not change as speed changes or with different wheels.
The drag on the rear wheel is reduced by 25% due to the seat tube.
The forgoing applies to zero yaw angle. Read the paper if you want to know the results for non-zero yaw angles.

Coefficients of Drag Reported for Various Wheels (1)

Wheel / Cxo
Conventional 36-spoke 0.0491
Campagnolo Shamal 16-spoke 0.0377
HED CX 24-spoke 0.0379
Specialized tri-spoke 0.0379
FIR tri-spoke 0.0382
HED disk (lenticular) 0.0361
ZIPP 950 disk (flat sided) 0.0364

[The Shamal is not a particularly aero rim; however, is does have low count bladed spokes, and is significantly more aero than a standard wheel.]

Doug

http://www.analyticcycling.com/
here's some data - thanks Doug nmMrDan
Feb 12, 2003 8:18 AM
I can neverOldEdScott
Feb 12, 2003 10:17 AM
make heads nor tails out of Analytic Cycling's stuff. :-(
MebbeRimfired
Feb 12, 2003 9:46 AM
the reason why he rides what his sponsors tell him to is precisely because it doesn't make a damn of difference to his speed, but does to his bank balance?
This whole topic has 2 very curious aspectsrogue_CT1
Feb 12, 2003 8:43 AM
I'll have to agree with SK on this one. I can perceive no difference between my normal 14g $250 Velocity wheelset and my $600 Ksyrium SL's on the flats or while decending. I want the Ksyrium's to be faster because I paid so much, but there is no difference. When I get to a hill I do notice that the Kysrium's will respond better. Why? Because they are lighter, and the hub/spoke assembly transfers torque better than the other wheels. I also use Hed 3's. They are the most aerodynamic wheels in existance but I can not tell that by the seat of my pants. I can tell that once they are up to speed it takes slightly less effort to maintain that speed, but as far as an actual MPH difference I have no idea. For example: On the same flat road doing a 40K TT, with the Velocity wheels vs the Hed3 wheels, I don't notice that I am suddenly increasing my speed from 25 mph to 28 mph with just a wheel change. What I do notice is that the effort to maintain 25 mph is @ 176 bpm on my HRM with the Velocity wheels. With the Hed 3 wheels the same 25 mph is obtained @ 172 bpm. This allows me to increase heart rate to 178 which will raise my speed to about 26 - 26.5 mph. In my experience that is the only way I can find a true and measurable difference in wheel aerodynamics.
My K's are faster then my Heliums, same hill, time after time nmPaul
Feb 12, 2003 7:25 AM
Multiple effects, some brought about by other posters...MrDan
Feb 12, 2003 8:14 AM
First, the comment about the amount of wind/turbulence experienced with the spinning wheel test is excellent.
Now combine this with the total aerodynamics. The less turbulence created by spnning wheels, the less interference that turbulence has with the aerodynamics of the total package of rider/bike. I'll grant you that "It's not about the bike", but indeed it has enough effect to be worth going after for racing, and in particular the longer events, since the more energy you conserve, the better you are able to compete. Pro racers are in enough pain as it is, but alas Lemonds comment to the effect that - It never gets easier, only faster - rings true always.
what about bearings?Shad
Feb 12, 2003 1:48 PM
My nucleons "feel" faster to me as well, but I attribute that to the quality wheel bearings used in the hubs in addition to other reasons - real and imagined.

I know when I replaced the stock bearings in my rollerblades with high quality Swiss bearings, I was absolutely faster and have much more glide. Perhaps the bearings/hubs in the wheel have an impact as well.
what about bearings?DougSloan
Feb 12, 2003 1:54 PM
How do Nucleon bearings compare with Campy Record? If they are the same, then that can't be it for me.

Doug
re: Bladed spokes? How much difference?Woof the dog
Feb 15, 2003 2:56 AM
wow, i just read this whole thread.

What a waste of my time! I can't believe it.

Woof the dog.