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Wheel Energy

Which tyres for Paris-Roubaix? Whose time trial bike is fastest? Suspension mountain bikes or singlespeeders? Talk equipment here.

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Wheel Energy

02 Feb 2011 06:55

I note this item:
http://www.cyclingnews.com/features/tech-feature-the-work-of-wheel-energy

It makes no mention of the role of aerodynamics when considering the speed of a tyre. It's more than just rolling resistance. Wider can also be slower as a result, even though rolling resistance may be less.
User avatar Alex Simmons/RST
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02 Feb 2011 07:48

Most of the article is written in a sufficiently specific way that aerodynamics don't matter because conclusions are not drawn. However, I assume you are talking about this statement:

"Unless you're a pure climber and solely focused on weight, the takeaway message here is that you'll go generally faster on wider rubber even if it's slightly heavier."


in which case you are entirely correct. It reads like an off the cuff summary that hadn't been fully thought through. I doubt that Wheel Energy themselves would have said that without qualifying with a comment on aero.
User avatar Martin318is
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02 Feb 2011 13:22

The most significant thing I got out of the interesting article was that latex tubes can have 10% less rolling resistance that standard .6mm butyl. I'm glad I ordered soem Michelin latex tubes the other day. Hmm, now I just need to pump them up daily.

The part about 25mm tyres being faster than 23mm got to me a little though. Should we all be riding around on 25's?
User avatar Indurain
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02 Feb 2011 14:59

Alex Simmons/RST wrote:I note this item:
http://www.cyclingnews.com/features/tech-feature-the-work-of-wheel-energy

It makes no mention of the role of aerodynamics when considering the speed of a tyre. It's more than just rolling resistance. Wider can also be slower as a result, even though rolling resistance may be less.


...and yes, the operative term here is, can, as in, potentially...but the newest Zipp wheels, for instance, are relatively wide yet claim to have better aerodynamics, especially at yaw angles ( and they require a wide tire to achieve the full performance Monty )...

...if you have the time, the Weight Weenies are all over this and visiting/reading their site will acquaint you with some of the salient points/discussions in this area.... the prevailing opinion there seems to be that aerodynamics trumps all...then Crr...followed closely by weight...but there is also the opinion that the relationship between hysteresis and real world tire performance has not been fully explored and that this area may prove to be fresh ground for performance improvements ( the wide tire idea, use of latex inner tubes and a questioning of accepted common knowledge about the relative benefits of tire pressure being some examples...and the to a lesser extent the effect of various breaker strip materials on performance, which by the way can be felt and therefore fall in that important 5% range of difference and that is not insignificant..oddly enough it is Continental, that was famous for making tires that wore like iron and rode that way, that has done the most research in these fields and have as a result have improved their tyres by a significant margin....)

Cheers

blutto
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02 Feb 2011 15:29

Alex Simmons/RST wrote:I note this item:
http://www.cyclingnews.com/features/tech-feature-the-work-of-wheel-energy

It makes no mention of the role of aerodynamics when considering the speed of a tyre. It's more than just rolling resistance. Wider can also be slower as a result, even though rolling resistance may be less.


The aerodynamic differences from tire to tire or even clincher to tubualar is so insignificant that it's not even worth mentioning, good that their was no mention of it otherwise I wouldn't have read further. I should remind you that when HED came out with their C2 (23mm wide) rims they had some utterly unbelievable aero claims posted right on their site about the resulting aero benefits on a tire that has been spread out 3mm. I think enough people called them out on it that they eventually took it all down and just resorted to their stupid graphs that they always use. Further proof that no matter what you do in this industry every company is going to lie about something to make more money. After reading this you'll be able to break the speed of light. :rolleyes:
User avatar RDV4ROUBAIX
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02 Feb 2011 15:40

Indurain wrote:The most significant thing I got out of the interesting article was that latex tubes can have 10% less rolling resistance that standard .6mm butyl. I'm glad I ordered soem Michelin latex tubes the other day. Hmm, now I just need to pump them up daily.

The part about 25mm tyres being faster than 23mm got to me a little though. Should we all be riding around on 25's?


...the daily pumping up issue can be solved to some extent by using a butyl-latex inner...Veloflex use these in their tubies to good effect...the other advantage that the latex inner has is somewhat better puncture resistant...

...as for the use of the 25 mm tyre...a good compromise is using it on the rear where Crr is a bigger issue and aerodynamics are compromised by dirty air...dropping a wide tire on a rim that is not an ideal aerodynamic match is not an ideal solution for the front where aero is the more important performance parameter...so a 23mm/25mm combo could be the best of all worlds...

Cheers

blutto
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02 Feb 2011 17:06

Jeez, that didn't take long. So, blutto, you're saying 2mm difference from front to rear is more aero? C'mon, really? Anyway, back to the HED example, if you'd like to dig back in the cyclingnews archives, a couple years ago the very 1st test of the new Ardennes wheelset even James Huang brought up some skepticism of what HED was claiming at the time to be a 30-40% improvement in aerodynamic performance of a 23mm tire mounted to a 23mm rim. Hogwash! HED removed that claim from their site in a quick hurry because it was clearly made up and a utter lie. Besides, when has any of these C2 wheels ever been raced in their namesake, like the Ardennes? Never, because they're all on tubulars. Seems like a lot of effort and fluff to sell a consumer wheelset, no? The aerodynamic performance claims by manufacturers is probably the most dishonest topic that the bike industry is propagating on the general consumer, and doing it purely for sales, I know because I spent years in meetings with these same mfg's dreaming up lies about this stuff by using altered, or even fake data. Forums like weightweenies is where you'll find the sheep and fanatics that believe everything the manufacturers tell them like you'll be more aero or save so many watts with 2mm less here, much faster with 20g savings there. It's all collusion by the industry and the motive is profits, that's it.
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02 Feb 2011 17:55

RDV4ROUBAIX wrote:Jeez, that didn't take long. So, blutto, you're saying 2mm difference from front to rear is more aero? C'mon, really? Anyway, back to the HED example, if you'd like to dig back in the cyclingnews archives, a couple years ago the very 1st test of the new Ardennes wheelset even James Huang brought up some skepticism of what HED was claiming at the time to be a 30-40% improvement in aerodynamic performance of a 23mm tire mounted to a 23mm rim. Hogwash! HED removed that claim from their site in a quick hurry because it was clearly made up and a utter lie. Besides, when has any of these C2 wheels ever been raced in their namesake, like the Ardennes? Never, because they're all on tubulars. Seems like a lot of effort and fluff to sell a consumer wheelset, no? The aerodynamic performance claims by manufacturers is probably the most dishonest topic that the bike industry is propagating on the general consumer, and doing it purely for sales, I know because I spent years in meetings with these same mfg's dreaming up lies about this stuff by using alterd, or even fake data. Forums like weightweenies is where you'll find the sheep and fanatics that believe everything the manufacturers tell them like you'll be more aero or save so many watts with 2mm less here, much faster with 20g savings there. It's all collusion by the industry and the motive is profits, that's it.


...congratulations...your career as a provider of lies for the industry has been an absolute ripping success....to the point where everyone including riders competing at the highest levels have bought into the lies that apparently you helped create about aerodynamics...

....if you have the time you can take our collective hands and we would love to hear the story of the truth about aerodynamics and the bicycle industry...this would be a great opportunity to give back to the cycling community what you have taken away with your very successful lying...

Cheers

blutto
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02 Feb 2011 18:24

This is the world of marketing and advertising, it's all based on lying for your money sorry to say. There's a point in the product development process at any large company where the marketing dept. takes over with ultimate control over what and how something is presented to the general consumer. Could you imagine what the world would be like if advertising was left up to engineers?
User avatar RDV4ROUBAIX
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02 Feb 2011 18:40

RDV4ROUBAIX wrote:This is the world of marketing and advertising, it's all based on lying for your money sorry to say. There's a point in the product development process at any large company where the marketing dept. takes over with ultimate control over what and how something is presented to the general consumer. Could you imagine what the world would be like if advertising was left up to engineers?


...so where is the truth that was asked for...appears my life had been a delusion and now all I ask for is clarity so that I can move forward knowing better...

...so given your response are we to assume you don't know the truth...or maybe the truth doesn't really exist because there are different views of it ( as in one from marketing and one from engineering ) that can't be reconciled easily into one nice neat truth....or is your default setting simply stuck at marketing and you were blowing smoke earlier and now you are furiously trying to cover your tracks...

...inquiring minds need to know...we want to go...can you make us go...to the land of truth in aerodynamics...

Cheers

blutto
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02 Feb 2011 18:53

The point missed here is one of diminshing returns. A 20mm tire is more aerodynamic as it reduces the frontal area, but adds rolling resistance.
The 23mm front/25mm combo may be closer to ideal.
Somewhere out there are the results of another series of wind tunnel tests and crr data, which suggest that drag created by the front wheel matters more than the tire size and composition. Will look for that one in my bookmarks...
RDV--the number of smart people working in the bike industry on the technical side is far greater than on the marketing side!
Give the geeks some credit.
In all likelihood the marketing half-wits have misunderstood what the geeks have told them, or are simply twisting the facts to boost sales. However, I wouldn't necessarily put Hed in that category.
User avatar TexPat
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02 Feb 2011 19:05

Wow, folks, a lot of interesting discussion going on here.

Let's put aside the issue of aerodynamics for a moment, though. True, cutting drag is very important for racers but everyday riders who are mostly out for recreation, there are other factors that are generally weighed more heavily - namely ride quality, tire grip (and thus safety), puncture resistance, and for lack of a better term, how easy it is to get and keep the bike moving.

Barring big aerodynamic gains (like switching from box-section to deep-section rims, for example, which is definitely very readily noticeable), the stuff I discussed in that article are what I believe most casual riders really care about.

Is a 23mm tire less aerodynamic than a 25mm one? Probably.

Are most recreational riders likely to care? Probably not.

As always, the pros and cons of all of this are heavily dependent on the target audience. Either way, it's nice to see that some companies are taking a more scientific approach to tire development so that we can all stand to benefit.
James Huang
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02 Feb 2011 19:57

Useful aerodynamics (and there are some, but no way with a tire) are the least of your worries if you're not racing for fun, or getting paid to do it, while the majority of people who buy aerodynamic or light 'things' for their bikes don't even race. Anyway, so back to the OP. If you win a race on a set of 23's, you would've done the same thing on 25's, clincher or tubular and visa versa. None of these ever so slight 2-3mm here, 10-20g there don't really mean a thing. I'm usually riding 25's and 28's because more air volume feels better for putting in the junk miles, now I find out that they actually roll better than smaller tires. Great!
User avatar RDV4ROUBAIX
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02 Feb 2011 20:15

TexPat wrote:RDV--the number of smart people working in the bike industry on the technical side is far greater than on the marketing side!
Give the geeks some credit.
In all likelihood the marketing half-wits have misunderstood what the geeks have told them, or are simply twisting the facts to boost sales. However, I wouldn't necessarily put Hed in that category.


Oh, I'm fully with you on that first point, but HED is just as guilty as any other mfg that makes false claims, they're all doing it. I know a couple peeps that work there and I could see any one of them pulling Steve aside and saying, hey we can't back that data up. Bad to make claims like that in the first place, but good on them for correcting it I guess.
User avatar RDV4ROUBAIX
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02 Feb 2011 20:29

James Huang wrote:...the stuff I discussed in that article are what I believe most casual riders really care about.

Is a 23mm tire less aerodynamic than a 25mm one? Probably.

Are most recreational riders likely to care? Probably not.

As always, the pros and cons of all of this are heavily dependent on the target audience. Either way, it's nice to see that some companies are taking a more scientific approach to tire development so that we can all stand to benefit.


Thanks for worrying about the details that matter to the "rest of us." I find it hard to believe that anyone that isn't racing at the top pro level can really discern the aero and weight differences in bike products.

I'm a lot more concerned about safety, convenience, and comfort. No matter how "fast" a tire, it's not faster if I'm changing flats or crawling out of the ditch. The barista doesn't know when I left home, so she's none the wiser if I show up for coffee 10 seconds later.
AnythingButKestrel
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02 Feb 2011 20:42

James Huang wrote:Wow, folks, a lot of interesting discussion going on here.

Let's put aside the issue of aerodynamics for a moment, though. True, cutting drag is very important for racers but everyday riders who are mostly out for recreation, there are other factors that are generally weighed more heavily - namely ride quality, tire grip (and thus safety), puncture resistance, and for lack of a better term, how easy it is to get and keep the bike moving.

Barring big aerodynamic gains (like switching from box-section to deep-section rims, for example, which is definitely very readily noticeable), the stuff I discussed in that article are what I believe most casual riders really care about.

Is a 23mm tire less aerodynamic than a 25mm one? Probably.

Are most recreational riders likely to care? Probably not.

As always, the pros and cons of all of this are heavily dependent on the target audience. Either way, it's nice to see that some companies are taking a more scientific approach to tire development so that we can all stand to benefit.


...gee...thanks for weighing in on this topic....BTW luv your contributions to CN....you and Steve Hogg make CN real special...

...(and sorry if this comes off as blubbering fan-boy but genuinely humbled...)

Cheers

blutto
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03 Feb 2011 02:48

Is this the article/review on the Hed Ardens?

http://www.irvinebicycles.com/articles/hed-ardennes-not-breaking-making-new-rules.html

I don't see the blue text they refer to.

I am also having trouble finding the CyclingNews Tech article that showed that the 20mm front wheel improved aerodynamics.

Now, before anyone gets into a huff about aerodynamics. I think most of us readers are interested in improving our riding or bikes in general and although most are convinced we will never set a land speed record we still strive to beat our friends or other riders on a ride to the city limits sign or some other known marker on the road no matter how petty or insignificant it maybe in the grand scheme of somebody else's riding plan/goals. So even though none of us will be listed in the results page of CyclingNews.com we still want to improve in the ways we can and use information accordingly or even improperly to somebody not striving for the same result.

So can we go on with the aero information? :cool:
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03 Feb 2011 04:03

ElChingon wrote:Is this the article/review on the Hed Ardens?

http://www.irvinebicycles.com/articles/hed-ardennes-not-breaking-making-new-rules.html

I don't see the blue text they refer to.

I am also having trouble finding the CyclingNews Tech article that showed that the 20mm front wheel improved aerodynamics.

Now, before anyone gets into a huff about aerodynamics. I think most of us readers are interested in improving our riding or bikes in general and although most are convinced we will never set a land speed record we still strive to beat our friends or other riders on a ride to the city limits sign or some other known marker on the road no matter how petty or insignificant it maybe in the grand scheme of somebody else's riding plan/goals. So even though none of us will be listed in the results page of CyclingNews.com we still want to improve in the ways we can and use information accordingly or even improperly to somebody not striving for the same result.

So can we go on with the aero information? :cool:


Sure, that diagram showing what wider rims do to this aerodynamics of a tire hoopla means absolutely nothing in the real world. The amount of drag a 23mm tire on a 19mm rim compared to 23mm rim is so small it's not even worth mentioning, but when HED 1st released this wider rim they claimed absolutely ridiculous numbers like 30-40% more aero than a traditional setup, and quickly took that down when they couldn't back up those #'s, you're just not going to "feel" any aero advantage whatsoever. If this was some groundbreaking advance in aerodynamics all the pros would be riding 23mm wide clinchers, but they don't, they ride tubulars. What you do feel is like you're on rails, as if on a tubular. Cornering grip is vastly improved for 2 reasons, takes less psi to get to an optimal pressure, you basically run 10-20psi less than usual, secondly the sidewall is more supportive and not rolling as with the lightbulb profile on a standard 19 or 20 wide rim. I like 23mm wide rims, build with the Velocity A23 on a regular basis, and I ride them almost everyday and they do roll great.

Here's the 1st review that cyclingnews did back in '08.
http://www.cyclingnews.com/reviews/hed-ardennes-wheels

Note the 3rd paragraph about aerodynamics of the tire/rim combo:

While we don’t have any independent scientific data to verify HED’s claims of improved aerodynamics and lower rolling resistance, we can comfortably say that they don’t feel any slower yet offer a much-improved ride quality, a smoother feel overall and vastly improved grip. At under 1400g a pair, they are also some of the lightest non-carbon clinchers we’ve encountered.


And there still isn't any test proving that this rim/tire set up gives any usable or significant aero advantage, probably because there isn't any.
User avatar RDV4ROUBAIX
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03 Feb 2011 05:06

RDV4ROUBAIX wrote:....they claimed absolutely ridiculous numbers like 30-40% more aero than a traditional setup...


I think that is the key point for me (and it very much highlights RDV4ROUBAIX argument I think):

What the hell does, "X% more aero" actually mean?

Cycling component companies are always happy to tell us that putting this headstem on will make us faster because it is 20% more aero. And they will VERY happily write material to make the credulous masses think that this means the entire bike and rider combination will therefor be 20% more aero and therefor 20% faster.

What a bunch of.......

As Alex Simmons/RST highlighted at the start of this thread, I think that aerodynamics should have been mentioned in the article and that no conclusions of the type I quoted should have been inserted into it.

Incidentally, regarding that statement about wider tyres - does that mean if I use 80mm tyres I will be faster than on my current 23mm ones? It seems written that way :D
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03 Feb 2011 05:23

[quote="AnythingButKestrel"]Thanks for worrying about the details that matter to the "rest of us." I find it hard to believe that anyone that isn't racing at the top pro level can really discern the aero and weight differences in bike products.[quote]

I agree and disgree.

Does an extra 20% of rolling resistance, weight or aerodynamic drag "matter" to me, in so far as is my livelihood affected? Of course not.

But am I able to feel a qualitative difference? He11 YEAH!
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