so what's state-of-the-art in "aero road" frames? [Archive]

kgreene10

12-31-2012, 10:17 PM

What's the difference between the S5 and the S5vwd. I know what the letters stand for, but the Cervelo website doesn't help me figure out how the two offerings differ. Anyone know? Do they differ in ways that affect aerodynamics?

Also, that Bicycling Magazine graphic seems to reveal something pretty astonishing -- riding a Tarmac can be like pushing 2.5kgs more than riding an S5vwd. At my FTP, I would have to produce 10 extra watts if riding the Tarmac just to keep up with myself on the S5vwd. In a race that would make a massive difference.

54ny77

12-31-2012, 10:24 PM

how about those neilpryde frames?

FlashUNC

12-31-2012, 10:30 PM

Louis

12-31-2012, 10:35 PM

Maybe its my end and I'm missing something in the graph, but a 250 gram difference is not 2.5 kg.

In addition to that, drag is a force, and grams measure mass, not force. Doesn't make any sense.

thegunner

12-31-2012, 10:36 PM

Maybe its my end and I'm missing something in the graph, but a 250 gram difference is not 2.5 kg. At 250 grams, its just a quarter of a kilogram. Might still make a difference for some racers I suppose.

Those are grams of drag :) not quite the same as weight.

In addition to that, drag is a force, and grams measure mass, not force. Doesn't make any sense.

i THINK this is normalized somehow -- should be assessed vs. CdA, but doesn't really matter since it's an apples to apples comparison

To answer the above I think vwd frames used a different layup of carbon. Slightly lighter, significantly more expensive.

wallymann

12-31-2012, 11:37 PM

. .. At my FTP, I would have to produce 10 extra watts if riding the Tarmac just to keep up with myself on the S5vwd. In a race that would make a massive difference....

IMO that's the where these aero bikes like the S5 matter...if you're on the rivet at the max power you can give, just conjuring up an additional 10-20 watts has REAL meaning to me. training with a powermeter, i know how tough it is to add that capacity thru improved condition....VERY TOUGH. and the fact youre saving a few watts here, and a few watts there, in energy exertion when riding sub-maximally means you have more matches left to play with after a long tough day in the saddle.

kgreene10

12-31-2012, 11:47 PM

My great uncle once said to me "son, if there's one piece of wisdom I'd like to pass on it's this: never post on New Year's Eve. No good can come from it. I'm tellin' ya straight."

I should have listened to old Abe.

Yes, 250 grams is not, as I mistakenly said, 2,500 grams.

Right, force and mass are different.

So, no, the S5 wouldn't save me 10 watts at ftp compared to the Tarmac. And that's a good thing really because that S5 looks hideous! (If you disagree and are mad at me for it, gimme a break -- I'm still posting message on New Year's Eve. Sorry Abe!)

Louis

12-31-2012, 11:56 PM

Chance

01-01-2013, 02:17 PM

In addition to that, drag is a force, and grams measure mass, not force. Doesn't make any sense.

Is it any different than our use of pounds to measure mass? Pounds mass and pounds force are commonly use even though not completely correct.

For this case 1 pound equals 454 grams. Hence 250 grams is just over 1/2 pound of drag force.

Chance

01-01-2013, 02:19 PM

Something interesting about the data is that the "drag" is not symmetric with yaw angle.

I have to believe that that difference is nearly 100% due to the drivetrain components on the rhs of the bike. Knowing that most of the drivetrain drag has to come from the crank and derailleurs, and knowing what those look like, you can get a relative feel for how, for a given yaw angle, the drag is affected by something of known area and shape.

Great observation Louis. Also points out to me that the data comparing bikes may change significantly if a rider was sitting on the bike. The best bike without rider may not be the best with rider.

verticaldoug

01-01-2013, 02:48 PM

(it's all marketing. There's also an MIT article in Bicycling some time ago, but I am too lazy to look. If you really want to be aero, get rid of water bottle and cages and wear a hydration pack on you chest. )

by Linda Patch

MIT Wind Tunnel Testing Reveals Secrets to Faster Cycling
I've got my geek on today, so let's talk cycling efficiency. I see so many of my friends spending gazillions of dollars on anything that they think will make them faster. Here's some actual science that will help with just that, and it just might save you a bundle.
The synopsis of the MIT wind tunnel testing came from Tim Richmond at Max Performance. I happily re-post it for your viewing pleasure. Here's a link to the original article on bicycling.com.

Based on the MIT research:
Can you pass the following aero-test?
What produces more drag- your wheels or your helmet?
True or False- 75% of how fast you go is determined by your body positioning?
Does water bottle placement drastically affect aerodynamics?
Here are the answers to these questions and some additional rules of thumb for all triathletes. Here's how to increase bike speed without spending big bucks.

Want to increase your bike speed and spend money wisely?

Any speed above 12 MPH makes it worth being in an aero position on aero bars
A non-aero helmet creates 4x the drag of a nonaero wheelset
Roughly 2/3 of drag is created by the cyclist
Cable routing actually affects aerodynamics materially
A water bottle on your seat tube is much more aero than one on your down tube
Making your race number fit flatter drastically affects aerodynamics
Your bike accounts for about 15-25% of your overall drag
The MIT ranking of value in terms of cost/second saved for practical triathletes is:

Detailed factors, e.g. cable routing, race #, etc.
Helmet
Position
Frame
Wheels
Note - the water bottle shape was actually considered 2nd most important but was tested using a MIT custom designed one not available to the public.

There are trade-offs though, between body positioning aerodynamics and power output efficiency. It's not effective if you are super aerodynamic but losing lots of pedal power because of your positioning. Proper bike fit will help you in this regard since it determines a comfortable and aerodynamic position on the bike.

Final Takeaways:

So, you now have more information on whether to spend $2,000 on a wheelset or $200 on a helmet. Aerodynamics is critical since a 5% improvement can mean big time savings. Every rider is different too, so there is no single right answer for everyone. Are shaved legs faster than hairy ones? And just how geeky will I look in that aero-helmet?

rice rocket

01-01-2013, 03:17 PM

If you really want to be aero, get rid of water bottle and cages and wear a hydration pack on you chest. )

Litespeed designed their frame to have bottles in mind, I believe it's actually less aero with the bottles removed. Each size frame also has a slightly different aero shape to suit the differences caused by going to different sizes.

Anyways, I have a Litespeed C2. I paid $1100, which is half the price of a Madone 5-series or a Specialized Tarmac. My aero advantage, however slight, is pretty much free. I'll take free.

jlwdm

01-01-2013, 05:26 PM

Not a direct answer to your question, but the best aerodynamics bicycle work is being done at Faster in Scottsdale. Faster has the only wind tunnel optimized for bicycle speeds. Go to the Faster Blog and read the articles on the left if you are really interested in bicycle aerodynamics:

http://www.ride-faster.com/blog/aerodynamics-for-cycling-%E2%80%98the-scientific-application-of-body-position-to-reduce-drag-forces%E2%80%99/

There are five pages on the left so make sure you use the arrow to get to pages 4 and 5.

Jeff

palincss

01-01-2013, 05:41 PM

http://www.bicycling.com/bikes-gear/bikes-and-gear-features/cheating-wind-1

http://www.bicycling.com/sites/default/files/images/data_aero_graph_0.jpg

Is this with, or without, the rider aboard? I strongly suspect it's without rider, and if so I wonder whether you see anything like this difference with the rider on board.

rnhood

01-01-2013, 05:48 PM

Robbos

01-01-2013, 08:07 PM

All the latest in cutting edge aero bike design- aerodynamic tubes, internal cable routing, chainstay mounted brakes. :rolleyes:

thegunner

01-01-2013, 08:15 PM

It was without a rider/dummy so you're right, the actual realizable differences with a rider in the saddle would pretty much be moot. Its going to take significantly more wind drag (faster speed) to make a realizable different I would think.

eh, I think even with a rider -- considering equivalent position/setups on each rig -- the difference would still exist on a proportional level. especially since it's the leading edge that ultimately disturbs the airs flow, i'd imagine the front wheel/headtube junction would still have a significant effect (to the magnitude of 10+ watts on something super-aero vs. a tarmac for instance).

it's still there -- putting a rider affects the overall drag and to some extent the effectiveness of certain 'back of the bike' enhancements like aero seatposts/hidden rear brakes etc. but by the time the wind hits the rider's legs, i'd guess it's already turbulent.

Chance

01-01-2013, 09:18 PM

eh, I think even with a rider -- considering equivalent position/setups on each rig -- the difference would still exist on a proportional level. especially since it's the leading edge that ultimately disturbs the airs flow, i'd imagine the front wheel/headtube junction would still have a significant effect (to the magnitude of 10+ watts on something super-aero vs. a tarmac for instance).

it's still there -- putting a rider affects the overall drag and to some extent the effectiveness of certain 'back of the bike' enhancements like aero seatposts/hidden rear brakes etc. but by the time the wind hits the rider's legs, i'd guess it's already turbulent.

That's a bad assumption in my opinion. Agree anything up front will be affected by rider much less than at the rear of the bike, but even at the rear there is much aero effect. Otherwise we wouldn't see differences for rear disc wheels versus a traditional. Even at the front the rider makes a difference. It's not like we ride at supersonic speeds. Our bodies can affect what is in front of it too to some degree. Not much perhaps but some.

thegunner

01-01-2013, 09:51 PM

That's a bad assumption in my opinion. Agree anything up front will be affected by rider much less than at the rear of the bike, but even at the rear there is much aero effect. Otherwise we wouldn't see differences for rear disc wheels versus a traditional. Even at the front the rider makes a difference. It's not like we ride at supersonic speeds. Our bodies can affect what is in front of it too to some degree. Not much perhaps but some.

i'm not suggesting our bodies don't play into it -- i'm simply suggesting that the net effect is likely to be close to the same (if you consider the rider equivalent) as the non-rider measurement. i think HED at some point published a paper showing that the front wheel had something like an 80:20 split in drag reduction -- that is, replacing the front with a JET9 + box section rear would be 80% as aero as a pair of JET9's. if this is the case, then the portion of the rider in the same horizontal plane as the bike is already in turbulent air -- at that point it's just a matter of how the flow truncates at the trailing edge.

Bob Ross

01-02-2013, 07:41 AM

Based on the MIT research:
Roughly 2/3 of drag is created by the cyclist
Your bike accounts for about 15-25% of your overall drag

Wait, wut?

oldguy00

01-02-2013, 08:06 AM

Interesting that this past year, most of the cervelo riders (Garmin) didn't use the S5. They opted for the R5, or the older S3, I believe.
Really makes you wonder about the claims of 20-25 watts gained that Cervelo was claiming with the S5..........................

oldpotatoe

01-02-2013, 08:13 AM

i'm not suggesting our bodies don't play into it -- i'm simply suggesting that the net effect is likely to be close to the same (if you consider the rider equivalent) as the non-rider measurement. i think HED at some point published a paper showing that the front wheel had something like an 80:20 split in drag reduction -- that is, replacing the front with a JET9 + box section rear would be 80% as aero as a pair of JET9's. if this is the case, then the portion of the rider in the same horizontal plane as the bike is already in turbulent air -- at that point it's just a matter of how the flow truncates at the trailing edge.

All true.....it's marketing, yes? Windtunnel w/o rider so they can put a number on it and point to it. Like weight and price...all about the bike, not the rider.

PLUS an 'aero' road machine in the middle of the peloton..aero-ness and disturbed air means ohhsolittle.

For the above post, I think something like 85% of the energy is to overcome wind resistance, most made by the rather un-aero thing called a cyclist. With those big, round, un aero things moving up and down, called legs.

Joachim

01-02-2013, 08:24 AM

Sort of funny story.... On the group ride yesterday an unexperienced rider on a Cervelo S5 VWD with Super Record EPS and Zipp Firecrest tubulars said "this bike is really saving me at least 25 watts or even more. I am the back of a 40-man group, doing 25mph and hardly pedaling. I just wonder what I'm going to do when I flat since my battery pack is in my saddle bag and I don't know how to change a tubular".

truebeliever

01-02-2013, 08:29 AM

thegunner

01-02-2013, 08:54 AM

All true.....it's marketing, yes? Windtunnel w/o rider so they can put a number on it and point to it. Like weight and price...all about the bike, not the rider.

PLUS an 'aero' road machine in the middle of the peloton..aero-ness and disturbed air means ohhsolittle.

For the above post, I think something like 85% of the energy is to overcome wind resistance, most made by the rather un-aero thing called a cyclist. With those big, round, un aero things moving up and down, called legs.

sorry old spuds -- disagree with this mindset here. aero road bikes aren't meant to shine in the middle of a peloton, that's like saying an r5ca is mediocre for time trials. of course it is. that's not what it was intended for.

fact of the matter is -- if you put the same rider, same fit on an s5 vs. someone on say, a nice lugged steel number, the guy on the s5 will go faster. it's not all about the rider.

palincss

01-02-2013, 09:16 AM

eh, I think even with a rider -- considering equivalent position/setups on each rig -- the difference would still exist on a proportional level. especially since it's the leading edge that ultimately disturbs the airs flow, i'd imagine the front wheel/headtube junction would still have a significant effect (to the magnitude of 10+ watts on something super-aero vs. a tarmac for instance).

it's still there -- putting a rider affects the overall drag and to some extent the effectiveness of certain 'back of the bike' enhancements like aero seatposts/hidden rear brakes etc. but by the time the wind hits the rider's legs, i'd guess it's already turbulent.

I think it would be a mistake to simply assume that with a rider aboard the differences would exist on a proportional basis. It may well be that the wind drag caused by the rider is of such a magnitude as to render any differences in frame wind resistance insignificant, nothing but "noise".

There's only one way to know, and that is to test and measure. Of course, that's unlikely to happen, because it's not in the manufacturers' interest to point out that a change in rider clothing and rider position can produce a change in wind resistance many times greater than that produced by aerodynamic tweaking of frame and components. You can't sell rider position, and if you're a bicycle manufacturer you're selling bikes, not clothes.

rice rocket

01-02-2013, 09:29 AM

I think it would be a mistake to simply assume that with a rider aboard the differences would exist on a proportional basis. It may well be that the wind drag caused by the rider is of such a magnitude as to render any differences in frame wind resistance insignificant, nothing but "noise".

There's only one way to know, and that is to test and measure. Of course, that's unlikely to happen, because it's not in the manufacturers' interest to point out that a change in rider clothing and rider position can produce a change in wind resistance many times greater than that produced by aerodynamic tweaking of frame and components. You can't sell rider position, and if you're a bicycle manufacturer you're selling bikes, not clothes.

This is the position that all you skeptics take, the record is broken, find a new one. ;)

Velonews did a test, testing position, wheels, helmet, etc., holding power constant. The test was conducted at a NASCAR oval. Let me try to find the article.

thegunner

01-02-2013, 09:29 AM

I think it would be a mistake to simply assume that with a rider aboard the differences would exist on a proportional basis. It may well be that the wind drag caused by the rider is of such a magnitude as to render any differences in frame wind resistance insignificant, nothing but "noise".

There's only one way to know, and that is to test and measure. Of course, that's unlikely to happen, because it's not in the manufacturers' interest to point out that a change in rider clothing and rider position can produce a change in wind resistance many times greater than that produced by aerodynamic tweaking of frame and components. You can't sell rider position, and if you're a bicycle manufacturer you're selling bikes, not clothes.

cervelo tests with a dummy mold of dave zabriskie aboard. the differences seem to exist on a proportional basis across most yaw angles (until about 15* at which point it stalls WITH rider). this isn't to say that it would be true across the board with every rider, but i feel like a lot of people on this board seem reluctant to grasp an idea so well backed by testing.

oldguy00

01-02-2013, 09:38 AM

cervelo tests with a dummy mold of dave zabriskie aboard. the differences seem to exist on a proportional basis across most yaw angles (until about 15* at which point it stalls WITH rider). this isn't to say that it would be true across the board with every rider, but i feel like a lot of people on this board seem reluctant to grasp an idea so well backed by testing.

Cervelo was claiming something like a 25 watt difference with their S5 frame. That is HUGE. HUGE! Even if the difference were only half that, why wouldn't every rider on the team be begging to have one?
The marketing bull**** gets tiresome.
And as you mention above, when providing numbers for frames, wheels, etc., the companies will usually give the best number that of course only occurs under very specific conditions/angles......meaning that the real world differences are far different...
I have an S3 and I love it mainly for how it looks.. :) But I don't feel I have any real advantage with it over a round tube frame..

559Rando

01-02-2013, 09:56 AM

Worth a glance (or a study)

http://www.bikequarterly.com/images/BQ61coverMR.jpg

thegunner

01-02-2013, 09:57 AM

Cervelo was claiming something like a 25 watt difference with their S5 frame. That is HUGE. HUGE! Even if the difference were only half that, why wouldn't every rider on the team be begging to have one?
The marketing bull**** gets tiresome.
And as you mention above, when providing numbers for frames, wheels, etc., the companies will usually give the best number that of course only occurs under very specific conditions/angles......meaning that the real world differences are far different...
I have an S3 and I love it mainly for how it looks.. :) But I don't feel I have any real advantage with it over a round tube frame..

because at some point, i'm sure other ride qualities trump aero. i'm not saying that aero is the end-all be-all, but the fact that so many people seem to think that it's 100% marketing is equally annoying.

sorry, as a former matsci/chem-eng nerd -- fluid mechanics is a soft spot of mine, and disregarding good (albeit skewed) science is ridiculous to me.

rice rocket

01-02-2013, 10:08 AM

Chance

01-02-2013, 11:48 AM

Here's the test I was referring to, I remembered the details slightly wrong (speed was held constant, and power was the dependent variable), but the numbers are there.

http://www.bikeradar.com/road/gear/article/how-aero-is-aero-19273/

Interesting. So in one set of conditions changing from road to TT helmet saves just less than 10 watts at about 40 km/hr and in another set of conditions changing from the same road helmet to same TT helmet saves about 34 watts. Everything else being held constant in both cases.

If you believe this data, it confirms my previous point that we can't treat aerodynamic drag incrementally. The idea that a bike will hold "proportional" advantages with and without a rider on top of it is scientifically flawed. In fluid dynamics the theory of superposition doesn't hold true when applied to aerodynamic drag.

oldpotatoe

01-02-2013, 12:13 PM

because at some point, i'm sure other ride qualities trump aero. i'm not saying that aero is the end-all be-all, but the fact that so many people seem to think that it's 100% marketing is equally annoying.

sorry, as a former matsci/chem-eng nerd -- fluid mechanics is a soft spot of mine, and disregarding good (albeit skewed) science is ridiculous to me.

ok, 89% marketing...

If it were 'good' science, it wouldn't be skewed, yes?

The 'science' doesn't include the biggest variable, the rider. Traveling at a very slow in comparison, 20 or so MPH, generating a 1/4 horsepower or something?

93% marketing....

rice rocket

01-02-2013, 12:28 PM

ok, 89% marketing...

If it were 'good' science, it wouldn't be skewed, yes?

The 'science' doesn't include the biggest variable, the rider. Traveling at a very slow in comparison, 20 or so MPH, generating a 1/4 horsepower or something?

93% marketing....

I don't see why you think it's skewed?

Maybe the watts don't total up to what you think is significant, but the numbers are there. It's faster, in all situations.

Whether you choose to buy a frame based on velocity-based superlatives is your own prerogative, but I'm not sure where you're finding the skewness here.

thegunner

01-02-2013, 12:31 PM

I don't see why you think it's skewed?

Maybe the watts don't total up to what you think is significant, but the numbers are there. It's faster, in all situations.

Whether you choose to buy a frame based on velocity-based superlatives is your own prerogative, but I'm not sure where you're finding the skewness here.

it's probably my fault for using the word skewed. i don't see how it's any different than a clinical study that shows the merits of certain drugs. you wouldn't stop taking medicine because the studies are presented in a good light for pharmaceuticals would you?

people keep mentioning that they ignore the rider in these tests -- that's entirely untrue. like i said, cervelo does its testing with a model rider on board. the difference is still quantifiable (and non-trivial). << this is what really bothers me.

verticaldoug

01-02-2013, 12:42 PM

Last year german 'Tour' Magazine had a big spread on various interations of a rider/bike combo going aero. All test were at 40kph. The rider started on hoods, regular helmet, jersey , round tubes etc. I think the initial reading was around 470 watts. They went to drops, then clip ons, then aero helmet, then tribike down various levels in position. The final low number was around 340 watts for a rider aggressively positioned on a tribike in skinsuit, shoecovers, aerohelmet etc. The final bike was a Giant Trinity. The bike, rider position did not look rideable in my opinion. (Okay , maybe for a german mutant professional cyclist , but not for your average joe)

I'd think position will slightly change depending on whether your are tt is a prologue, vs 40km vs half iron/full iron. The amount of short term discomfort you can stand has to factor in. Will the efficient frontier for drag vs power be the same for all distances?

oldpotatoe

01-02-2013, 12:59 PM

I don't see why you think it's skewed?

Maybe the watts don't total up to what you think is significant, but the numbers are there. It's faster, in all situations.

Whether you choose to buy a frame based on velocity-based superlatives is your own prerogative, but I'm not sure where you're finding the skewness here.

Well, they aren't really significant, IMHO and can't be reliably duplicated day to day because a rider's performance isn't consistent, day to day.

For it to be complete science, it needs to consider all variables and the variable-ness of a rider cannot be predicted with any certainty. Why they measure the frame in a sterile environment w/o a rider on it.

Racing a aero bike in a peloton 'may' make you faster, may not..depends on too much. If it was an automatic, all racers would use them but as has been mentioned, some teams don't.

In addition, putting a dummy onto the bike and measuring it..the dummy isn't moving around and such..I'd say the science is incomplete at best.

Sure there can be generalities but that IS sent to the marketing department, and painted by the sales guys as absolutes.

Quote-"It's faster, in all situations."

Nope.

FlashUNC

01-02-2013, 01:00 PM

Does aero make a difference? Sure. There's enough data out there to support that it does. I'm guessing Heinrich Haussler would want whatever gains he could have made to beat Cav in San Remo a couple years back.

I don't mean to speak for oldpotatoe and others, but I tend to fall in the camp that for the average cyclist, it really doesn't matter. I'd be better off losing 10 pounds than worrying about saving 10 or 20 watts thanks to a super aero frame. Would it be a marginal gain? Yeah, and that may matter for your pro trying to win a national championship or a stage in the Tour.
But I can think of far cheaper ways for the average Joe to get faster than worrying about the aero-ness or the road frame, where the variables are constantly changing on the road.

Joachim

01-02-2013, 01:09 PM

thegunner

01-02-2013, 01:34 PM

Well, they aren't really significant, IMHO and can't be reliably duplicated day to day because a rider's performance isn't consistent, day to day.

For it to be complete science, it needs to consider all variables and the variable-ness of a rider cannot be predicted with any certainty. Why they measure the frame in a sterile environment w/o a rider on it.

Racing a aero bike in a peloton 'may' make you faster, may not..depends on too much. If it was an automatic, all racers would use them but as has been mentioned, some teams don't.

In addition, putting a dummy onto the bike and measuring it..the dummy isn't moving around and such..I'd say the science is incomplete at best.

Sure there can be generalities but that IS sent to the marketing department, and painted by the sales guys as absolutes.

we don't do that for anything... even things accepted as scientific fact.

oldpotatoe

01-02-2013, 01:50 PM

we don't do that for anything... even things accepted as scientific fact.

So it's not done, so lets' do even less with a bicycle..Jaoquim summed it up. It's a data point but not 'science'.

beeatnik

01-02-2013, 01:58 PM

As a former Econ major, I like the phrase "all things being equal."

In the last year, I've ridden three frames equally. Litespeed C1, CAAD10 and Moots Compact Sl. All three bikes have identical set ups. I think the aero claims, under real world conditions, are mostly marketing (87.5%). With all 3 bikes, I've posted equal times on sprints, rollers, 2 mile long false flats. And we're talking group rides and solo. Time's are consistent to the second. That said, the C1 is faster on short steep descents. Scary fast. I'm always the guy passing on the left because I'm flying at 2-3mph faster (coasting, not tucked) than the group. So, if you're interested in an aero frame, expect to enjoy its benefits about once or twice per ride, for about 30 seconds. YMMV.

palincss

01-02-2013, 01:59 PM

This is the position that all you skeptics take, the record is broken, find a new one. ;)

In the endless hail of cycling related bull$hit we're all subjected to, skepticism is the only rational position. There's only so much koolaid a person can drink, after all, before it starts coming out every bodily orifice.

Joachim

01-02-2013, 02:02 PM

There's only so much koolaid a person can drink, after all, before it starts coming out every bodily orifice.

Awesome :).

oldpotatoe

01-02-2013, 02:06 PM

In the endless hail of cycling related bull$hit we're all subjected to, skepticism is the only rational position. There's only so much koolaid a person can drink, after all, before it starts coming out every bodily orifice.

What he said...or believe the things said everyday on most ad bplaces when it comes to bicycles.

Look at Cyclingnews.com or Velo.com and look what they say on the ads presented.

But if RiceRocket or Gunner want an aero frame and it helps them in some way, fine and dandy.

rice rocket

01-02-2013, 02:13 PM

N = 1, funny, even with within-subjects measurements. Not saying it has no benefit, I just would not call it science. It's a data point. Nothing more. Reliable? Maybe for average Joe. Not for scientists.

I think the N is like up to 10 now, given all the bicycle mags that try to all do the same thing. ;)

The real question is, have anyone tested data that disproves that there is an advantage, however slight it might be? I haven't seen any yet.

palincss

01-02-2013, 02:24 PM

people keep mentioning that they ignore the rider in these tests -- that's entirely untrue. like i said, cervelo does its testing with a model rider on board. the difference is still quantifiable (and non-trivial). << this is what really bothers me.

Actually I asked if they ignored the rider. I said I had my doubts.

What I gathered from the article rice rocket posted was that the largest savings were from aero helmet [i.e., "clothing"} and rider position, not frame aerodynamics.

Quoting from the article: "The difference between the Specialized road helmet and the TT2 was 8.6W or 9.4W, depending on which set of protocols we chose. The difference between the Specialized Tarmac SL2 with clip-ons and the Transition was 18.5W or 19.3W. Finally, the difference between a road frame and one with a set of clip-ons on it was a whopping 29.4 watts. This difference is due to rider position (in the drops vs. in the aero bars). That's 60 watts accounted for in savings."

On a dollars-for-savings basis, that is, dollars per watt saved at 40 km/hr the article found:

Clip-on bars $100-1200 $3.30-$40
Aero helmet $75-230 $8.30-25.50
Time trial bike $1000-10,000+ $50-500
Aero wheels $600-$8000 $60-800

So if aero helmets are potentially up to 20 times more cost effective than time trial bikes, and up to 32 times more cost effective than aero wheels, why is it, I wonder, that aero wheels are seen everywhere on ordinary recreational rides, and even time trial bikes are becoming more and more common, especially on centuries, but you never ever not even once see aero helmets? Is it because they look so godawful goofy?

oldpotatoe

01-02-2013, 02:25 PM

I think the N is like up to 10 now, given all the bicycle mags that try to all do the same thing. ;)

The real question is, have anyone tested data that disproves that there is an advantage, however slight it might be? I haven't seen any yet.

This horse is beginning to smell but why do some of the Garmin guys choose to not ride the most aero frame? If there is always an advantage?

Maybe some disadvantages?

rice rocket

01-02-2013, 02:29 PM

Yeah, the S5 rides like ****. :)

Joachim

01-02-2013, 02:30 PM

Sometimes just acting aero is cool enough...

martinrjensen

01-02-2013, 02:30 PM

you know, I really think that all this discussion about more aero and how much you can save is only in retrospect. i.e. if everything else is equal then yes, someone with a more areo bike will win, but winning a race is in the riders mind. If you want to win, or more impoirtantly know you are going to win, I think you could strap bricks to the guys back and he still would figure out a way to win.

zap

01-02-2013, 02:56 PM

state of the art in "aero road" frames............a rider who can ride a bicycle comfortably and fast 25+mph (flat terrain) in the drops (back flat with the ground) for hours.

If you can't do that, aero frames don't matter. If you ride tubulars it matters even less.....

oldpotatoe

01-02-2013, 03:05 PM

Yeah, the S5 rides like ****. :)

"The real question is, have anyone tested data that disproves that there is an advantage, however slight it might be? I haven't seen any yet."

So I guess you have seen 'it', the data.

verticaldoug

01-02-2013, 03:12 PM

So it's not done, so lets' do even less with a bicycle..Jaoquim summed it up. It's a data point but not 'science'.

I think the science on aero is good. The data point is going to a triathlon and seeing the triathlete in the aero helmet, tribike, aero wheels riding on the horns because they did not train enough to hold position for 56 or 112 miles.

rice rocket

01-02-2013, 03:18 PM

"The real question is, have anyone tested data that disproves that there is an advantage, however slight it might be? I haven't seen any yet."

So I guess you have seen 'it', the data.

This thread is about the aero qualities of a frame, is it not? :fight:

oldpotatoe

01-02-2013, 03:53 PM

This thread is about the aero qualities of a frame, is it not? :fight:

But since ya gotta ride it, it can't be taken in isolation, just the aero qualities.

There are no doubt about 'aero' qualities of a recumbent, when going down hill(and some gravity) but the disadvantages outweigth those advantages..same for aero Cervelo.

Same for disc wheels, front and back...more aero, and tri bars, another one, no doubt but 'drawbacks' make it not the best choice.

So aero road frames aren't 'faster in every instance'.

Just funnin' with you now..don't get spooled up.

you too gunner.

CDM

01-02-2013, 07:48 PM

My 2 year old daughter just came in and asked me "what's that" while pointing to the computer. I told her I was reading about riding bicycles. She asked "Why?" I read this whole discussion and I have no idea why.

thegunner

01-02-2013, 08:06 PM

This horse is beginning to smell but why do some of the Garmin guys choose to not ride the most aero frame? If there is always an advantage?

Maybe some disadvantages?

spudsie - it's physics. once the incline hits 6%+ weight matters more than aero.

hence the r5 was born.

then they needed another bike that was cushier for roubaix and the likes.

hence the r3/rs was born.

the most aero frame is only the best when you can ride it comfortably for hours and on courses that aren't tilted upwards. better?

rice rocket

01-02-2013, 09:24 PM

Aren't most bikes (except Pinarello, har har) at the 6.8kg limit?

martinrjensen

01-02-2013, 09:28 PM

Learn, you read to learn. Now if she asks why learn, well she might have a point. Sometimes I don't know myselfMy 2 year old daughter just came in and asked me "what's that" while pointing to the computer. I told her I was reading about riding bicycles. She asked "Why?" I read this whole discussion and I have no idea why.

oldpotatoe

01-03-2013, 07:50 AM

spudsie - it's physics. once the incline hits 6%+ weight matters more than aero.

hence the r5 was born.

then they needed another bike that was cushier for roubaix and the likes.

hence the r3/rs was born.

the most aero frame is only the best when you can ride it comfortably for hours and on courses that aren't tilted upwards. better?

Never 'worse'....'bikes' remember, bike stuff not Syria or heart disease.

ok gunnie?

Bob Ross

01-03-2013, 08:02 AM

There are no doubt about 'aero' qualities of a recumbent, when going down hill(and some gravity) but the disadvantages outweigth those advantages...

Playing devil's advocate here (since I've never ridden a 'bent in my life and, despite being endlessly fascinated by them, would probably never be caught dead on one...mostly because my wife would divorce me)

What "disadvantages"?

oldpotatoe

01-03-2013, 08:22 AM

Playing devil's advocate here (since I've never ridden a 'bent in my life and, despite being endlessly fascinated by them, would probably never be caught dead on one...mostly because my wife would divorce me)

What "disadvantages"?

-Heavy, unless you spend a ton of $, then still heavy, compared to a 'bike'.
-Unique to 'bent' parts, particularly the various steering 'systems'-underseat, over seat, etc, wheels, tires.
-Hard to see from or be seen on-cannot really turn around to look, low, need flags, cannot 'standup' to climb-see 'heavy' above, when climbing. No Camelbacks or packs.

IF you cannot ride an upright bicycle for some reason, a good way to ride a self propelled vehicle. But if you don't have some sort of physical 'reason' to ride one, I think they answer no question, solve no problem with regards to a well fitting upright.

Like some other things 'bike', they have been around in various incarnations for a long time but have failed to become mainstream in any meaningful way.

IMHO-

here we go...we'll see if this morphs into a 'discussion'.

CDM

01-03-2013, 08:45 AM

Learn, you read to learn. Now if she asks why learn, well she might have a point. Sometimes I don't know myself

I didn't learn anything from this therefore I wonder why I bothered to read it.

rice rocket

01-03-2013, 10:25 AM

mostly because my wife would divorce me)

What "disadvantages"?

Haha, so judgmental!

54ny77

01-03-2013, 10:38 AM

http://i.imgur.com/Iu1mj.jpg

AgilisMerlin

01-17-2013, 04:26 PM

http://i.imgur.com/Iu1mj.jpg

backward pedalerer'

Uncle Jam's Army

01-17-2013, 04:49 PM

Given my recent devolution to pauper status, my LBS buds are trying to line me up on a Scott Foil frameset at a crazy low price to race this year. So I'm going to be "aero" whether I like it or not, irrespective of the science (or lack thereof).

carpediemracing

01-18-2013, 12:03 AM

I didn't read the whole thread so...

I'm absolutely fascinated by recumbents. I was lucky enough to be able to check out (and briefly ride) one of the first land speed record attempt bikes. It was carbon fiber, hand-and-foot powered, 3 wheels, ultralight. Heiden rode it in the attempt. I rode it in 1985? Maybe 1984. Whatever a super long time ago. The builder said that the brakes failed and Heiden ended up hitting the net trap at the end of the straight and that the fairing was completely filled with smoke. A set of modern day disc brakes would totally revive that bike.

At some later point, maybe 1990 or so, I was fortunate to meet someone who was building a narrow 3 wheel recumbent with a full fairing. It tilted, had a multi link suspension, but I felt it would be too heavy for the SW part of Connecticut, at least with just a person pedaling it. He was designing it to accept a very small engine or motor in the back (fuel or electric). I have no idea what happened with that project.

I always thought that an efficient recumbent with a very small engine would work really well as an ultra efficient vehicle. It could probably go really fast with very little power but the whole issue with safety would be a huge problem.

So anyway I test rode a few recumbents that I worked on in the shop but that's it. I liked the low three wheel versions the best but they're the least practical on the road - too wide, too low, and cornering hard on them can be a bit nerve wracking.

I just saw on somewhere.. BikeRadar? the new Giant aero road bike. Very nifty looking. I wish I fit normal sized frames. I asked someone who has extensive bicycle wind tunnel experience about aero road frames - it's something that I think will take over in the racing scene, with all the talk about incremental gains - and he said, look, it gets you maybe half a kph in a sprint, maybe a full kph. The rest of it... it'll be hard to quantify what you get from the aero frame because your body is so much more significant in terms of drag. Slight changes to you or your kit is much more significant than anything you can get from the frame.

On the other hand even a 5 second per hour gain from a frame is always a 5 second per hour gain. Is it worth it? I don't think it is for me, I ride such a small frame. For someone who rides a tall frame, maybe it is. I've won races by 4 or 5 inches, races that took an hour to finish, and very often I've lost races by 5 or 10 feet. If the other guy had an aero road bike would he have won instead? I don't know. If I had an aero road bike or more aero wheels or whatever could I have won some of those 10 foot losses? I don't know.

Charles M

01-18-2013, 07:23 AM

S5
tmr01
Giants new aero

rice rocket

01-18-2013, 07:39 AM

S5
tmr01
Giants new aero

I saw pics of that Giant, looks clean as hell, but V brakes all around doesn't have me too psyched. But maybe that's because I'm lazy about brake adjustments.

LO^OK

01-19-2013, 07:47 AM

Actually I asked if they ignored the rider. I said I had my doubts.

What I gathered from the article rice rocket posted was that the largest savings were from aero helmet [i.e., "clothing"} and rider position, not frame aerodynamics.

Quoting from the article: "The difference between the Specialized road helmet and the TT2 was 8.6W or 9.4W, depending on which set of protocols we chose. The difference between the Specialized Tarmac SL2 with clip-ons and the Transition was 18.5W or 19.3W. Finally, the difference between a road frame and one with a set of clip-ons on it was a whopping 29.4 watts. This difference is due to rider position (in the drops vs. in the aero bars). That's 60 watts accounted for in savings."

On a dollars-for-savings basis, that is, dollars per watt saved at 40 km/hr the article found:

Clip-on bars $100-1200 $3.30-$40
Aero helmet $75-230 $8.30-25.50
Time trial bike $1000-10,000+ $50-500
Aero wheels $600-$8000 $60-800

So if aero helmets are potentially up to 20 times more cost effective than time trial bikes, and up to 32 times more cost effective than aero wheels, why is it, I wonder, that aero wheels are seen everywhere on ordinary recreational rides, and even time trial bikes are becoming more and more common, especially on centuries, but you never ever not even once see aero helmets? Is it because they look so godawful goofy?

Conditioning... many/most road&tri cyclist are conditioned by years of ceaseless marketing propaganda about the benefits of aero wheels, and lately and to a lesser degree, about the aero frames. As a result big spending on aero wheels is perceived as reasonable and justified. In contrast there were no such concerted efforts to promote the aero helmets hence the general stigma.