# aero road wheels



## Lab Worker (May 31, 2004)

I've been thinking about getting a set of event-only wheels for my Roubaix. I'm currently running DT R1.1 rims on Hugi 240 hubs, 32x3 front and rear. They are a very nice set of wheels, but all this talk of deep aero wheels has got me thinking that I'd like a pair.

I race a few times a year, but I'd like to start doing some time trials. I'd like a set of aero wheels that would be used for these purposes only (not ridden on a day to day basis). Most races are longer 80 - 160km events where the aero advantage would come into play more.

If money were no object I'd have Cosmic SLs, but spending that much money on a wheelset that would stay in the closet most of the time seams pretty dumb to me and my mediocor income.

I've been thinking about some Velociy Deep V's built onto a nice reasonably price light hub (something like Speedcifics for example), or prehaps a pair of American Classic 420's.

I've read mixed things about AM Classics, but it seams like if you get the CX Ray version they're alright. Seams like the rear hubs arn't great, but for the amount of use these wheels would get, I think they would be fine.

I like the idea of using off the shelf rims and hubs and building them up, rather than being trapped by buying BRAND X spokes that only fit one wheel.

Any other opinions?? I'm, 75-80 kilo, reasonably fit (300-400km/week), and ride on crappy surfaced roads.

Cheers!


edit: I should mention that I couldnt' be bothered with tubs, so clincers only please  No wheel waggon where I race


----------



## Al1943 (Jun 23, 2003)

I doubt that the Velocity Deep V's would give you any measureable speed increase over what you already have. You'll need rims with a really deep profile to see much improvement, then you can expect about 1/4 to 1/3 rd mph improvement when above 20mph. Wheels with deep profiles get pretty expensive unless you buy used, then buyer beware.

Al


----------



## AJS (Aug 7, 2003)

"Event only" wheels, then you're not going to be concerned about comfort, but more a wheel's ability to be stiff, but not too stiff to bounce too much on the rough pave. It also works together with the tires you have, and their PSI.

You gotta have rims at least 38-40mm deep to start getting a _significant_ aero advantage. Unfortunately, there aren't many Al models I can think of that you can buy and have built as customs. You'd probably have to go with pricey CF rims to do that.

Or, look for some good used factory aero wheels as Al1943 said. That's probably your best bet. I can highly recommend Campy Shamals, and they wouldn't bust your wallet.


----------



## spookyload (Jan 30, 2004)

Have you considered Nimble Crosswind Trispoke wheels. They are very pricey new, but can be had for around $500 on ebay if you keep an eye open. I just sold a set to someone from here for a great deal. He got one front and two rear wheels with tubies installed for half the price of a retail wheelset. They claim to be the most aero wheels for general conditions.


----------



## oxygen debt (Feb 4, 2004)

I'll sell you my set of spinergy xaero with yellow spokes for $350 shipped anywhere in the continental US. I bought them on sale for $450 and have only put @200 miles on them. *I don't race* and am only able to average around 16-18 mph solo and do not feel that I can truly benefit from their more aero profile. I will stick with my 32/3x wheels for now. Drop me a line [email protected]


----------



## AJS (Aug 7, 2003)

Yum! They would look mighty good on my black/gray frame w. yellow trim. Are they Campy or Shimano freehub?


----------



## oxygen debt (Feb 4, 2004)

Shimano...but I think you could use a Mavic cassette and get the right spacing for Campy.

Thanks, Andrew


----------



## Kerry Irons (Feb 25, 2002)

*Aero?*

No offense, but these wheels don't look very aero. The rim profile is too shallow for any significant effect, and the spoke count is not that low. About as aero as a MAVIC Ksyrium (IOW, not aero), from appearance anyway.


----------



## AJS (Aug 7, 2003)

Kerry Irons said:


> No offense, but these wheels don't look very aero. The rim profile is too shallow for any significant effect, and the spoke count is not that low. About as aero as a MAVIC Ksyrium (IOW, not aero), from appearance anyway.


True. The aero benefit won't be a whole lot over a standard box rim. When I bought my Zondas (30mm rim depth) it was more for the solidity and strength than aero-ness. But they do have 12F & 11R fewer spokes than yer regular 32H, and they're aero spokes so....it all helps.


----------



## Coolhand (Jul 28, 2002)

AJS said:


> True. The aero benefit won't be a whole lot over a standard box rim. When I bought my Zondas (30mm rim depth) it was more for the solidity and strength than aero-ness. But they do have 12F & 11R fewer spokes than yer regular 32H, and they're aero spokes so....it all helps.



AJS, take a good long look at the reviews prior to buying any Spinergy product. Trust me- it ain't pretty. . .


----------



## AJS (Aug 7, 2003)

Coolhand said:


> AJS, take a good long look at the reviews prior to buying any Spinergy product. Trust me- it ain't pretty. . .


Oh sheet, I weren't going to buy 'em. I think they'd look nice on my rig tho' and I could get extry style points . Who needs performance and reliability when you've got looks?!


----------



## johnmyster99 (Mar 2, 2004)

Here are my thoughts, as I also recently filled up my wheel closet with event and training wheels for my new roubaix...

Since you want aero clinchers...

To me, the American classic wheels seem to equate the Rolf Prima wheels, which I am a huge fan of. I just got in a set of their Elans, planning to use them for climbing events and crits. The AC 420s seem to use the same rim as the Prima Vigors, and the 350s seem to use the same rim as the elans. Correct me if I'm wrong, but they look suspiciously the same to me. Of course the drilling is different, because AC are traditionally spoked, and the Primas are paired. 

The Primas use a white industries hub, which should solve the freehub concerns of the AC wheelsets. Prima vigors are something like 43mm deep, and under 1500 grams. WAY less than cosmics, for those who are concerned with things like crit performance.

Also look at rolf prima's new offerings, like the eschelon and aspin. Reasonably more affordable, more all-around use wheelsets.

Other things to look at would even include trying to find a deal on some older vector pros, bontrager aeros, or even cane creek deep/aero wheels. Any of these would have varying merits in the weight/aerodynamics/ebay affordability departments. If weight isn't a real concern, there are a few other options in the 'cheap on ebay' aero type stuff.

Above all, I'd reccomend the Prima Vigors. Next, I'd look into their Eschelon model. www.rolfprima.com


----------



## stratoshark (Feb 2, 2004)

*rolf prices?*



johnmyster99 said:


> Also look at rolf prima's new offerings, like the eschelon and aspin. Reasonably more affordable, more all-around use wheelsets.


Before I contact a Rolf dealer, do you know the prices of the new models? I didn't see a price list on the Rolf website. Thanks.


----------



## johnmyster99 (Mar 2, 2004)

*prima*

I can't quote prices off the top of my head. Their dealership program is pretty easy to get along with. Any old bike shop could get a price sheet from them, if there isn't a shop in your area dealing with them. They're way friendly on the phone.


----------



## jumpstumper (Aug 17, 2004)

johnmyster99 said:


> I can't quote prices off the top of my head. Their dealership program is pretty easy to get along with. Any old bike shop could get a price sheet from them, if there isn't a shop in your area dealing with them. They're way friendly on the phone.


They are around $850 per set.


----------



## racerx (Jan 29, 2004)

*I hear what you are saying,*

but can you really not use tubulars?

Good old, tried and true Zipp 404 (or find a sweet deal on late model 440's) are the ticket for event only aero wheels.

Put som high presure Conti's on em and say goodbye to the pack...


----------



## euro-trash (May 1, 2004)

For the money Ksyrium Elites and Campy Zonda (available for both Campy and Shimano) are both really hard to beat. Aero and durable.


----------



## al0 (Jan 24, 2003)

johnmyster99 said:


> ...
> Above all, I'd reccomend the Prima Vigors. Next, I'd look into their Eschelon model. www.rolfprima.com


34mm Vigors, 31m Echelon. Not enough for real aerodinamic advantage.
You need 40 or even 45mm profiel.


----------



## AJS (Aug 7, 2003)

al0 said:


> 34mm Vigors, 31m Echelon. Not enough for real aerodinamic advantage.
> You need 40 or even 45mm profiel.


From what I understand, 38mm is where significant aero advantage begins, considering the typical width of most aero rims. That is not to say that less deep rims have _no_ wind-cheating properties, just not as much as deeper rims.


----------



## Kerry Irons (Feb 25, 2002)

*Confused by the numbers*



AJS said:


> 38mm is where significant aero advantage begins


Don't hang you hat on such a number. If you were to plot drag vs. rim height, you would see a smooth curve, not a step change or inflection point. This confusions is what happens when somebody does a wind tunnel study with a box section rim, a 30 mm rim, a 38 mm rim, and a 45 mm rim. Perhaps there was improvement at 35 mm, but that height wasn't tested. Similar to the studies on % protein for recovery foods - 20% protein was studied compared to no protein, and it was better. That doesn't mean that 20% is optimum (most sports nutritionists would suggest more like 10%) but "everybody" now says that 20% protein is THE answer.


----------



## AJS (Aug 7, 2003)

I had a feeling someone would pick that up as soon as I typed it. You're right, but I say 38mm. because that's usually the depth where "real" aero wheels start, insofar as there aren't too many rim models between about 30 up to 38mm, so it has to start somewhere. That's always been my take on it, but others may disagree. 38mm appears to be a somewhat arbitrary figure that somebody concocted for whatever reason to call a wheel "'aero".

On the 20% protein thing, I haven't seen anything about that whole debate, so I'd have to defer to you and others. But, I did recently pick up a box of Clif's 20% protein "Builders" bars, and all I know about them is they taste pretty good! I wondered what the 20% name on the box was about, so now I know.


----------



## bimini (Jul 2, 2003)

*The most aero combination is a Tri spoke front and*

a disk rear. In high wind conditions a tri spoke front and rear. These wheels are a little heavier than a spoked aero wheel like a zipp, but they are more aero and since you are talking about what seems like longer solo distances wheel weight is not a factor. (no sprinting or jumps).

You can find some deals on these now and then on ebay. If you can settle for an 8 speed setup you can find some real bargins on carbon fiber disks with 7-8 speed freewheels.

You can find some great deals on the Campy Shamals on ebay also. I got a set I really like. They are barely aero at about 40mm. They are on the heavy side (not a big deal on a solo ride).

My next set of wheels will probably be a set of Reynolds Stratus. A little more aero than the Shamals. I like crits and sprints. It is one of the lightest and stiffest wheelsets made and fairly aero to boot. (I think it is around a 48MM depth. Zipps are 58, slightly heavier and less stiff. I may end up with a Clydesdale version of the Zipp if I can't find an ebay bargin on the Stratus. I want the higher spoke count of the Clydesdale for the stiffness. I want a set of sprinters wheels, Aero is secondary since I have no plans on leading the pack. I hide out in the pack and wait for the sprint. Aero is not a big deal unless you are solo or in the front of things. 



Lab Worker said:


> I've been thinking about getting a set of event-only wheels for my Roubaix. I'm currently running DT R1.1 rims on Hugi 240 hubs, 32x3 front and rear. They are a very nice set of wheels, but all this talk of deep aero wheels has got me thinking that I'd like a pair.
> 
> I race a few times a year, but I'd like to start doing some time trials. I'd like a set of aero wheels that would be used for these purposes only (not ridden on a day to day basis). Most races are longer 80 - 160km events where the aero advantage would come into play more.
> 
> ...


----------



## poshscot (Dec 14, 2004)

found a couple of pieces of research that should end any arguments about whats fastest in a given condition - cant make head nor tail of some of it but it seems that shamals are the best alrounders acording to the second link.

http://www.soton.ac.uk/~aijf197/Wheel Aerodynamics/Executive Summary.htm#top

http://www.bsn.com/cycling/WheelAerodynamics.html


----------



## AJS (Aug 7, 2003)

I have seen similar test results about 4 years ago, and the Shamals came out as the #1 or #2 wheel in that as well.

I keep _telling_ you guys about Campy wheels!


----------



## poshscot (Dec 14, 2004)

AJS said:


> I have seen similar test results about 4 years ago, and the Shamals came out as the #1 or #2 wheel in that as well.
> 
> I keep _telling_ you guys about Campy wheels!


i totally agree with you AJS, my shamals are better than all my other wheels including Ks, revX, handbuilt chorus/open4 and the mavic cosmos.


----------



## asgelle (Apr 21, 2003)

poshscot said:


> found a couple of pieces of research that should end any arguments about whats fastest in a given condition - cant make head nor tail of some of it but it seems that shamals are the best alrounders acording to the second link.
> 
> http://www.soton.ac.uk/~aijf197/Wheel Aerodynamics/Executive Summary.htm#top
> 
> http://www.bsn.com/cycling/WheelAerodynamics.html


I don't think these references do much to end the discussion. The first uses a 2'x2' test section wind tunnel and half scale models for the wheels. No real wheels were tested so no conclusions about the performance of commercial wheels can be drawn. The second report is pretty out of date by now. The models tested are all several years old, and the vendor data has to be taken with a grain of salt if for no other reason than there's no way of determining whether a common testing protocol was used. 

As for the Shamals being best, I don't see it. Ignoring the vendor data, it looks to me that the Hed CX outperforms the Shamals at all reasonable wind angles (apparent wind angle over 15 degrees is extremely rare).

For a small fee, the best, most recent data is available at http://www.biketechreview.com


----------



## AJS (Aug 7, 2003)

Yes, these tests are dated, but in the Shamal's day, it was just about the fastest wheel you could "affordably" have. In my opinion and experience, (I owned a set of the sew-ups) it is a classic that has stood the test of time and probably millions of rider miles.

I agree about the testing methodology of that one link. Scaled down models are fine for some things, but for bike wheels it would seem you have to test the actual wheels for meaningful results. The models they made were really not a great facsimile to the actual designs.


----------



## naawillis (Oct 6, 2004)

AJS said:


> I had a feeling someone would pick that up as soon as I typed it. You're right, but I say 38mm. because that's usually the depth where "real" aero wheels start, insofar as there aren't too many rim models between about 30 up to 38mm, so it has to start somewhere. That's always been my take on it, but others may disagree. 38mm appears to be a somewhat arbitrary figure that somebody concocted for whatever reason to call a wheel "'aero".


ive noticed an increase actually, since you mention it, of manufacturers producing rims with profiles between 30 and 38mm. i think lots of it has to do with a growing market for aero wheels, but at 38mm you're dealing with serious weight issues. the companies, quite correctly, have latched on to the fact that lots of people want aero wheels for the look, but they cant justify buying a $1000 wheelset if it isnt at least 200g below the weight of their ksyrium. dropping 4mm off the whole profile saves those grams, and makes the wheel spec well in the minds of the consumers (i.e. they see reasonably low weight and reasonably deep profile). its people trying to have the best of both worlds. if you think that can happen, fine. i just see it as the future. the days of guys having both 1100g climbing wheels and 58mm crit wheels are fast ending. its just getting too damn expensive.


----------



## AJS (Aug 7, 2003)

naawillis said:


> ive noticed an increase actually, since you mention it, of manufacturers producing rims with profiles between 30 and 38mm. i think lots of it has to do with a growing market for aero wheels, but at 38mm you're dealing with serious weight issues. the companies, quite correctly, have latched on to the fact that lots of people want aero wheels for the look, but they cant justify buying a $1000 wheelset if it isnt at least 200g below the weight of their ksyrium. dropping 4mm off the whole profile saves those grams, and makes the wheel spec well in the minds of the consumers (i.e. they see reasonably low weight and reasonably deep profile). its people trying to have the best of both worlds. if you think that can happen, fine. i just see it as the future. the days of guys having both 1100g climbing wheels and 58mm crit wheels are fast ending. its just getting too damn expensive.


Like I said re: the Shamal's - "affordable" aero wheels, which meant aluminum rims. Back when Shamal's were produced, they sold for around $600., and there weren't so many choices in CF rims/wheelsets. Those that were uberlight aero CF's were too expensive for 90% of the roadie market to even consider. Unfortunately, although prices have come down somewhat, CF-rimmed wheelsets are still too expensive for many cyclists.

Yes, lightweight, strong, aero AND more affordable is the idea. (I also would like to have a secluded bungalow on Molokai.  ) Maybe we're starting to get there, but I think it will be at least 2 years or so in coming.


----------



## MShaw (Jun 7, 2003)

AJS said:


> Like I said re: the Shamal's - "affordable" aero wheels, which meant aluminum rims. Back when Shamal's were produced, they sold for around $600., and there weren't so many choices in CF rims/wheelsets. Those that were uberlight aero CF's were too expensive for 90% of the roadie market to even consider. Unfortunately, although prices have come down somewhat, CF-rimmed wheelsets are still too expensive for many cyclists.
> 
> Yes, lightweight, strong, aero AND more affordable is the idea. (I also would like to have a secluded bungalow on Molokai.  ) Maybe we're starting to get there, but I think it will be at least 2 years or so in coming.


I have some Cosmic 16/16 wheels. WAY fast once you get them up to speed. If yer TT-ing they're better than for crit racing.

I've also got a pair of 404s. About as aero but much lighter. Easier to spin up coming out of corners than the Cosmics. 

I've ridden several different wheels over the years. For crits my favorite compromise wheelset is a Ritchey Pro. Sorta aero, sorta light, durable enough to stay under my fat arse without much work.

My theory on aero wheels is that if they help you keep up with the faster guys (speeds 25mph+), they're worth the $$. If yer slow, don't bother. 

M


----------



## alienator (Jun 11, 2004)

Lab Worker said:


> I've been thinking about getting a set of event-only wheels for my Roubaix. I'm currently running DT R1.1 rims on Hugi 240 hubs, 32x3 front and rear. They are a very nice set of wheels, but all this talk of deep aero wheels has got me thinking that I'd like a pair.


So what do you think of your current wheels? Weight? Durable?

I'm curious about the wheels DT Swiss has been advertising, but I can't find any reviews of them. As opposed to other boutique wheels, the DT Swiss wheels look like wheels that you might actually have someone build for you....


----------



## spopepro (Dec 22, 2004)

*An idea*

I think the best bang for your buck may be on the reject hed 3 wheels. You can get them in clincher, and if you can deal with up to 4 hundreths of an inch of runout, a pair can be had for 750 bucks. It seems that a perfectly straight carbon wheel is just about impossable, so wheels within 3 hundreths of an inch are deemed "straight". I'm not sure how much that extra hundreth would make, but it may be the only chance at both very aero and rather cheap.


----------



## Lab Worker (May 31, 2004)

alienator said:


> So what do you think of your current wheels? Weight? Durable?
> 
> I'm curious about the wheels DT Swiss has been advertising, but I can't find any reviews of them. As opposed to other boutique wheels, the DT Swiss wheels look like wheels that you might actually have someone build for you....


I really like them.

I don't have "DT Wheels", I bought DT hubs and rims, and laced them with DT competition spokes and alloy nips. I wanted to buy the complete set of wheels straight from DT because they come with wheel bags and QR's, but they weren't in stock so I had to build them myself.

My wheels, as mentioned, are 32*3 front and rear, weights are 746 front and 910 rear, giving 1656 for the pair. Not too bad. They're not aero, but they are great in the gusty winds we get around here. They're comfy to ride on, latteraly stiff, and have a nice sound to the freehub....not King loud, but not too quiet either. Freehub engagment is quick and positive. Overall I'm really impressed with them, but to tell the truth I wish I had got King hubs. I just love the sound, and they're pure class 

I opted for these wheels over Dura Ace 10spd wheels becuase of the durability factor...i like the idea of being able to never true my wheels, and the fact that I can replace spokes easily, they don't have to be ordered in.


----------



## AJS (Aug 7, 2003)

Lab Worker said:


> They're not aero, but they are great in the gusty winds we get around here. They're comfy to ride on, latteraly stiff, and have a nice sound to the freehub....not King loud, but not too quiet either...Overall I'm really impressed with them, but to tell the truth I wish I had got King hubs. I just love the sound, and they're pure class


And some people complain about the angry bee sound. I think it helps you to go faster knowing they're after ya!


----------



## novice (Mar 12, 2004)

the 38mm aero rim standard comes from aerodynamic science. I think aerodynamic advantages begin with a 3:1 ratio of length versus width. I this case, a 19mm tire should be 19mm wide, meaning the rim plus tire length should be 19mm x 3. So, the rim should be 38mm, which is 19x3-19(height of the tire). It is for this reason that most aero rims are 19mm wide. This might not be absolutly correct, but I think this is what happens.


----------



## asgelle (Apr 21, 2003)

novice said:


> the 38mm aero rim standard comes from aerodynamic science. I think aerodynamic advantages begin with a 3:1 ratio of length versus width. I this case, a 19mm tire should be 19mm wide, meaning the rim plus tire length should be 19mm x 3. So, the rim should be 38mm, which is 19x3-19(height of the tire). It is for this reason that most aero rims are 19mm wide. This might not be absolutly correct, but I think this is what happens.


Very little of what you write is correct and it certainly doesn't come from aerodynamic science. There is no magic number for aspect ratio where if you are above there is aero benefits and if below there is no benefit. Do you really believe that a rim with aspect ratio 2.9999:1 shows no aero benefit while one at 3:0000:1 does? Also, if as you say 38mm is some ideal rim width, how do explain the prevelance of 58-60mm rims, not to mention disk wheels.

For wheels with similar shaped rims, drag will decrease monotonically with increasing rim aspect ratio (though the rate of decrease is not necessarily uniform). Data showing this can be seen at: http://www.zipp.com/tech/documents/ANoteonRimWidth_002.pdf


----------



## novice (Mar 12, 2004)

asgelle said:


> Very little of what you write is correct and it certainly doesn't come from aerodynamic science. There is no magic number for aspect ratio where if you are above there is aero benefits and if below there is no benefit. Do you really believe that a rim with aspect ratio 2.9999:1 shows no aero benefit while one at 3:0000:1 does? Also, if as you say 38mm is some ideal rim width, how do explain the prevelance of 58-60mm rims, not to mention disk wheels.
> 
> For wheels with similar shaped rims, drag will decrease monotonically with increasing rim aspect ratio (though the rate of decrease is not necessarily uniform). Data showing this can be seen at: http://www.zipp.com/tech/documents/ANoteonRimWidth_002.pdf


I never said that a 3:1 ratio was the optimal for ratio for aerodynamics. I said aerodynamic benefits begin around 3:1. The prevelance of 'deeper' rims is for a greater aero benefit, since I never said 3:1 was optimal, it should have been reasonable to assume that a ratio greater than 3:1 would yield a larger aero advantage. I am sorry if I did not imply this fact enough.

Oh, and on another note, I wouldn't use a study by a part manufacturer as absolute science. Especially one that both implies and concludes that their product is the best on the market. If you would like I can even explain to you why a dimpled surface has less drag than a smooth surface using the terms: laminar, turbulent, boundary layer, and pressure differential.


----------



## asgelle (Apr 21, 2003)

novice said:


> I never said that a 3:1 ratio was the optimal for ratio for aerodynamics. I said aerodynamic benefits begin around 3:1.


I know, and that's wrong. The aero benefit does not begin at any magic number. A 3:1 ratio is better than a 2.5:1 ratio and a 2.5:1 ratio is better than a 2:1 ratio. Look at the aero benefit of the Zipp 202 (with a depth of 25 mm) compared to ba GEL rim with less than 1:1 ratio.



novice said:


> Oh, and on another note, I wouldn't use a study by a part manufacturer as absolute science


I can understand why people might be skeptical of manufactures data especially when used to show the benefit of their products relative to other manufactures, but I think it's equally wrong to dismiss all data just because it comes from a manufacturer. In this case, the data (first graph) only compares Zipp products against each other to show the relative benefit of one model against another. Zipp has published white papers detailing their procedure to the point where I think an unbiased reader should have confidence in their data. [edit: Also, I wanted to refer to a free site. If you want, you can go to www.biketechreview.com and for a small fee seee wind tunnel data on wheels taken independently of any commercial sponsorship. The conclusions from that data would be the same as for Zipp's]



novice said:


> If you would like I can even explain to you why a dimpled surface has less drag than a smooth surface using the terms: laminar, turbulent, boundary layer, and pressure differential.


Who said anything about dimpled vs. smooth surfaces? [edit: I don't think a poster's background, academic or riding, is terribly relevant. A post should stand on its own merits not the reputation of the poster.] However, if you feel the need to prove your credibility just give me your publication list or the name you publish under and I can do a SciSearch for myself.


----------



## novice (Mar 12, 2004)

First off, by aerodynamic benifits I mean benifits noticable to a rider. You don't hear much from riders about aerodynamic gains with shallow rim depths. The shallowest rim/wheel that people claim an advantage is the campy shamal, 38mm deep. This is where I draw the line of aero or not. Your paper from zipp shows their 202 creates the same drag force at 0-10 degrees as the al rim, 20 flat spoke model, which I will assume is closer to the 202 in terms of spokes and pattern. Only in a 10+ degree crosswind does the 202 make gains, which would mean that there is a very strong wind from that direction making a rider concern about things other than aerodynamics, like remaining in control.

Second, I mean absolute science. I have seen other papers on aerodynamics of bicycle wheels and they all make a general conclusion, the deeper the wheel the greater the benefits. The link you originally posted is not a scientific paper; it is marketing with some science thrown in. Therefore I wouldn't trust that article.

Last, Zipp's literature mentioned the smooth vs. dimpled topic, I thought you might want to talk about that next. As far as papers, I haven't published any, don't want to publish, and most likely will not publish. I am not a reasearch scientist/engineer, and do not enjoy academia. And as far as a post standing on it's own merits, it should, but the reputation of a poster is often quesitoned here, and then usually his/her post.


----------



## asgelle (Apr 21, 2003)

novice said:


> First off, by aerodynamic benifits I mean benifits noticable to a rider.


Well isn't that interesting. Now you're applying a filter to the aero benefit. Where did that come from. Who's to say how sensitive a particular rider is; and furthermore, why does the benefit have to be noticable to matter. With time trials decided by a few seconds or less over 30 to 60 minutes, an aero advantage might not be noticable to the rider but still be very significant in terms of finish placing.



novice said:


> You don't hear much from riders about aerodynamic gains with shallow rim depths. The shallowest rim/wheel that people claim an advantage is the campy shamal, 38mm deep. This is where I draw the line of aero or not.


You can draw the line wherever you want. That's a personal value judgement. It doesn't mean your values are the same as everyone else's. Another person might feel there's no reason to get less than a 58mm rim, and a third might feel a 30 mm rim has enough benefit for her. There's no right or wrong here. Everyone has to decide for themself; but by understanding the magnitudes of the various effects, e.g., weight, drag reduction, durability, and cost, people can make more informed decisions. 




novice said:


> Only in a 10+ degree crosswind does the 202 make gains, which would mean that there is a very strong wind from that direction making a rider concern about things other than aerodynamics, like remaining in control.


First, by your own statement you admit there is an aero benefit from a 25mm rim. Second, an apparent 10 degree apparent wind of 30 mph means riding 29.5 mph with a 90 degree crosswind of only 5.3 mph. Do you really believe deep rims are difficult to control with a 5-6 mph crosswind? I know I've been out in 20 mph crosswinds with 58 mm rims without a problem.




novice said:


> Second, I mean absolute science. I have seen other papers on aerodynamics of bicycle wheels and they all make a general conclusion, the deeper the wheel the greater the benefits.


Exactly, there is no magic point where aero benefits begin and below which there can be no improvement.




novice said:


> The link you originally posted is not a scientific paper; it is marketing with some science thrown in. Therefore I wouldn't trust that article.


You miss the point. I cited the article for the drag data. Forget all the text. If you don't trust Zipp's data (though there's no reason not to), you can pay the small fee and see similar impartial data at www.biketechreview.com . The conclusions would be the same.


----------



## novice (Mar 12, 2004)

My original post was meant to as a baseline reagarding aero wheels. I did admit that a 25mm rim had some advantages but that doesn't mean all 25mm rims provide the same advantages; the zipp's have a unique profile and dimpled surface ( I think the 202s do). But hey, I'll admit defeat; but I still wouldn't purchase an 'aero' wheel with a rim depth less than 38mm. I also didn't realize that a 10 degree crosswind was only a 5.2mph crosswind at 30mph.


----------

