Aerodynamics

Discuss light weight issues concerning road bikes & parts.
NGMN
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by NGMN

Elviento you bring up some good points.

I actually think that the magnet bottle company offers the best real world option for aero bottles on road bikes. The crappy thing about aero bottles is that you don't want to train with them but they use a proprietary cage. Ergo, if one could use the same attachment mechanism for a standard bottle and an aero bottle; one could train with a standard and race with an aero bottle without any messing around with cages. Only problem, if you needed more than you could carry you would need to arrange for your special bottles.

Tough to say which bike is ever most aero, but the S5 seems convincing to me. Specialized never released data on the Venge, and they have been known to produce such data if they have it. I think the Foil is probably better than a standard road bike but not up to par with fully aero tubed bikes.

Most people have commented that because the Kamm tail has been around in the motor industry for so long it shouldn't really be patententable.

by Weenie


rustychain
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by rustychain

My memory* was that filling the space with two water bottles was the second most aero. Running an aero bottle on the TT bars being the most aero. That running water bottles behind the seat the least.

*Please note the memory part, this part is subject to spontaneous failure
WW Velocipedist Gargantuan

JamieL
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by JamieL

elviento wrote:I want to throw out a few topics for your consideration:

1. Brake design -- will it have to be changed? Maybe hydraulic brakes should be cosisdered? What about water bottle design? something more manageable than the Cervelo version but still provide significant aero improvement?

2. which of the modern aero road bikes are most aero (S5)?

3. The Trek article says Trek has applied for patent over Kamm Tail design on all bikes, but Scott already has the F01. So how does that work? Infringement?

4. Is there any article showing the conversion of weight savings (say 200g) to wattage savings in various riding conditions (flat, climbing, etc.). I wonder how the results stack up against the aero savings chart...

The bike has improved greatly over the past 100+ years with the past 15 years being most dramatic, yet I still see a lot to be improved in the future.

Of course, this will not affect the fact that we could all lose that gut. Or do an ear job like Pantani... maybe not...



I think the new Ridley Noah answers the first couple of questions, or at least it starts the discussion.
Integrated brakes on a road frame must result in a fair improvement in aeroness. Not too sure about hydraulics on a road bike, i've never had a problem locking up my wheels...

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khaostik
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by khaostik

hi,

In this article: http://www.rouesartisanales.com/article-15505311.html you can compare aerodynamic savings with weight savings...

Regards,

Filipe Dias

LegalizeMyCannondale
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by LegalizeMyCannondale

elviento wrote:A lot of manufacturers are making aero bikes


Of course they are, aero bikes looks great on pictures and the amateurs love them.

Aero = more material, which is not very WW in my opinion.

Unless you are really fighting for seconds, aero bikes are just too heavy and stiff - in my humble opinion,
based on watching a few Ironmans and seeing amateurs suffering with their Cervelos and Zipps 808/1080,
which would be much better off with some non-aero wheels such as Ksyrium etc. and lesser aero frames.

JasonS
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by JasonS

LegalizeMyCannondale wrote:
elviento wrote:A lot of manufacturers are making aero bikes


Of course they are, aero bikes looks great on pictures and the amateurs love them.

Aero = more material, which is not very WW in my opinion.

Unless you are really fighting for seconds, aero bikes are just too heavy and stiff - in my humble opinion,
based on watching a few Ironmans and seeing amateurs suffering with their Cervelos and Zipps 808/1080,
which would be much better off with some non-aero wheels such as Ksyrium etc. and lesser aero frames.


This really is dependent on course (flat vs hilly) and rider power / size is it not? If the course is flat than you pay almost no penalty for the extra weight, if you're climbing 6000ft than the penalty is significant and the aero advantage is small....

I believe that's what the article referenced further up the page is all about ;)

Jason S.
1984 Ciocc Designer (63) '84 Super Record = 21.9 lbs
2000 Serotta Atlanta (60) '01 Records = 20.9 lbs
2009 Cannondale Caad9 (60) '06 Record/Chorus = 17.4 lbs
2009 Trek Madone 5.5 (60) '07 Record = 14.8 lbs
2011 Strong Extralite [steel] (59) '08 Record = TBD

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prendrefeu
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by prendrefeu

Top Twenty of the Tour de France 2011:

1 Cadel Evans (Aus) BMC Racing Team
2 Andy Schleck (Lux) Leopard Trek
3 Fränk Schleck (Lux) Leopard Trek
4 Thomas Voeckler (Fra) Team Europcar
5 Alberto Contador Velasco (Spa) Saxo Bank Sungard
6 Samuel Sanchez Gonzalez (Spa) Euskaltel-Euskadi
7 Damiano Cunego (Ita) Lampre - ISD
8 Ivan Basso (Ita) Liquigas-Cannondale
9 Thomas Danielson (USA) Team Garmin-Cervelo
10 Jean-Christophe Peraud (Fra) AG2R La Mondiale
11 Pierre Rolland (Fra) Team Europcar
12 Rein Taaramae (Est) Cofidis, Le Credit En Ligne
13 Kevin De Weert (Bel) Quickstep Cycling Team
14 Jerome Coppel (Fra) Saur - Sojasun
15 Arnold Jeannesson (Fra) FDJ
16 Haimar Zubeldia Agirre (Spa) Team RadioShack
17 Christian Vande Velde (USA) Team Garmin-Cervelo
18 Ryder Hesjedal (Can) Team Garmin-Cervelo
19 Peter Velits (Svk) HTC-Highroad
20 Jelle Vanendert (Bel) Omega Pharma-Lotto

Number of non-TT road bikes that would be considered "aero" ridden during the tour by racers who finished in the top twenty of the 2011 Tour de France: 0

Will it make a difference on a one-day race (or stage) ? Possibly. It depends on the stage and the rider, really.

Of the number of classics this year, how many were won on an 'aero' road bike?
How many were won on an non 'aero' road bike?

Is there a way we can gather all of the Pro Tour sprint-finishes this year and see how many were won on an aero bike vs. how many were won against other riders on aero bikes?

Will this ultimately point to what we keep reminding ourselves all along: it's the rider that makes the difference most of all, and the frame the least in terms of 'aero' on a bike?
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lcoolb
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by lcoolb

prendrefeu wrote:[...]
Number of non-TT road bikes that would be considered "aero" ridden during the tour by racers who finished in the top ten of the 2011 Tour de France: 0


Because the GC is mostly determined in the mountains? Might be interesting to look at the GC's of flat(ter) stage races...

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prendrefeu
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by prendrefeu

lcoolb wrote:Because the GC is mostly determined in the mountains? Might be interesting to look at the GC's of flat(ter) stage races...


You didn't read the full post?
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djconnel
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by djconnel

prendrefeu wrote:Number of non-TT road bikes that would be considered "aero" ridden during the tour by racers who finished in the top twenty of the 2011 Tour de France: 0


Excellent post. The PR would have you believe with differences between aero and non-aero bikes are substantially larger than the relatively small differences between riders.

It's clear "ride quality" is missing from the aero-versus-round-tube analysis. And that's very hard to quantify.

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madcow
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by madcow

Not sure what this counts for as I can't give any real details but here's what I bring to the party.

A major bike manufacturer (one of the big guys) lets call them brand A held a meeting internally to discuss the emergence of aero road bikes. They thought they determined without any testing that these aero road bikes were pointless. Their reason was that they knew once a couple of round bottles were bolted to an aero road bike, most the aero savings would go out the window and you'd be left with a bike that isn't really any faster but does suffer from a loss of ride quality. A couple engineers argued that the others might be wrong, so they decided to test this. They went out and bought an aero bike from Brand B, which was thought to be the best design. They took Brand B to the windtunnel, fitted it with some round bottles and tested it. I'm told that the results were quite impressive. In their tests Brand B saved 125-175 grams of drag in almost every situation when compared to a more traditional frame (I'm assuming a traditional frame is a Brand A frame.) Brand A was quite impressed with the performance of Brand B's bike, and since this was them telling me how well a competitors bike tested, I can be reasonable sure it wasn't just marketing b.s. This is a company that I know spends lots of money on R&D and so I would respect their opinion when I believe it to be honest.

They did say that doing comparisons to their own acceptable standards for "ride quality" Brand B was outside of what they'd consider acceptable but that they had some ideas for their own aero road bike as to make it even more aero than the Brand B that they tested (this I have no doubts they can or did do.) and they also had some ideas to improve the ride quality.

I don't think I can say anymore than that without giving away the identity of brand A and brand B, so I'll just stop with that. Hopefully this adds something to the discussion.

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fa63
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by fa63

Thanks for the info, madcow.

I think your post gives us a pretty good idea of who Brand A (and B) might be.

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djconnel
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by djconnel

Lennard Zinn:

I took a Venge out on a four-hour ride in the Carmel Valley and over Laureles Grade back to the Specialized 2012 Product Launch in Monterey. While it is still quite a light bike that responds well to pedaling inputs, I think a rider would really have to drink the aero-testing Kool-Aid to choose it as his or her weapon of choice.... On the other hand, you don’t have to be particularly sensitive to feel the jarring while riding this bike on rough roads. The shoulder of the road in Carmel Valley is quite rough, and I couldn’t wait to get off of the Venge; it’s simply too harsh a ride for me,

spartan
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by spartan

thanks madcow for great post.


guess

Brand A - Trek
Brand B - Cervelo
Current Rides:

2017 Giant TCR Advanced SL 0 DI2 9150

rustychain
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by rustychain

Those numbers don't pass the BS test. Anyway without some idea of what or how they came up with them they are nothing. I'm waiting for the release of an aero bike with a tall headtube for a more comfortable position ;)
Really all this talk of aero road frames but more frames are being released with massive square downtubes and oversized head tuned. 5 to 1 is the ratio needed to be aero according to what I read, hence the UCI 3 to 1. Lotus was aero ( no fairings and not a recumbent) IMO these new aero frames are at best semi- aero-ish
WW Velocipedist Gargantuan

by Weenie


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