Thought I saw Big Geo. Hincapie w/ a Camelbak-like blue tube hanging down as he approached the finish line of today's TTT.

Yup noticed that too...another reason I find it odd, everyone doing their own thing. You would think they'd have tested it and found out the best solution. Or maybe that indicates they have tested it and found out aero bottles/bottle placement doesn't make a damn bit of difference?

I couldn't figure out why the P4's of the test team were using standard bottles.



Any ideas?

I thought the aero bottle / fairing was one of the biggest features of the P4. Is it that useless as a waterbottle?

Brad

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3SIXTY5cycling.com

yeah i thought at first maybe it was a sponsorship issue with the Elite bottle brand...but Elite even has their own aero bottle so no idea?

the uci declared the p4 bottle illegal

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Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter

We have a winner!!!!

Explanation? Bit of a hack job.

http://www.cyclingnews.com/...-for-last-minute-fix

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2016:
IMFL #12
http://www.bestbikesplit.com

I just glanced on today's recap show of the TTT, and I could swear one team had a single bottle in an off-the-back holder. Forget which team though

Aero bottles definitely matter -- even just at 0 degrees, a bare optimized bike can be up to 30 grams of drag better than a round bottle on the DT (on the Shiv/Transition). The aero bottle is about the same as a "clean bike" at low yaw.

The UCI has been wishy-washy on this one all year. We had issues at Paris-Nice running our aero bottle against the ST. UCI didn't like that. They've also been 50/50 on Cervelo (from what I've heard). Furthermore, since they've said they won't give warnings, they'll just DQ riders, no teams are taking chances.

That's why we're seeing round bottles. Aero does matter and don't ever forget that....

Mark
MITAerobike
Specialized Bicycle Components
Road Engineer/Aerodynamicist

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Mark Cote
MITAerobike
Specialized Bicycle Components

Mark, when you test bottles have you done it with a pedaling rider? While I know the problems involved with doing so, I do have to wonder--given the bottle's placement between the rider's legs, if the relative difference could change with and w/o a rider?

Just out of curiosity Mark, but what have you found is better at higher yaws, aero bottle or "clean bike" (with a rider)?



That must be frustrating...it's odd that one cannot get a "pre-blessing" from them that can be used to "educate" the commissaires if need be...what was the apparent "issue" with having the bottle up against the seat tube?




I remember Damon Rinard commenting somewhat about rider/mechanic/soigneur resistance to the "non-round" bottles as well (i.e. harder to grip, harder to mount, harder to fill, etc.) as part of the reason the Bontrager bottle wasn't used more by the Discovery crew. Are you saying if not for the UCI issues, the acceptance would be there?

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Then why, e.g., did Kristen Armstrong race with one in the ITT at the Giro Donne? (That's a rhetorical question, BTW.)

1. It isn't necessary to test with the rider pedaling, but it might be interesting to test with their legs in different positions (if they aren't actually pedaling, that is).

2. My own field tests (while pedaling, of course) with a low-slung cardboard "bottle" on a P3C demonstrated that it had minimal impact upon aerodynamic drag, at least at/near 0 deg of yaw.

I've done both many many many many times on various different bikes. Bottles still matter except on really bad DT bikes. I've tested pretty much every combo of bottle location/size on aero bikes over and over with and without rider.

As with every rider test, it's tough to get good repeatability (usually +/- 15 gF if done back to back) but you can still measure a difference with a rider, with and without bottle. So yes, DT round bottles are measurably worse than a bare aero bike (with a good DT).

Aero bottle results vary per frame. We designed ours to work well with Transition and the key competitor frames (P3C, TTX, DA, etc.) but not to the level of integration that Cervelo has done with the P4 bottle. We effectively wanted a bottle that head on would not hinder the bike but in crosswind could potentially give some lift. That's what we've ended up with -- a good usable bottle that meshes well with all kinds of frames.

Here's some data since we're on ST:
Preface: Shiv bike alone, Roval Rapide wheels w tubular tires (spinning), head-on drag normalized to 30 mph, rho=1.20; my typical protocol
Note, not yaw data here.

Bike, no bottles: 537 gF
(No pic, but same as below without bottle)

Bike, DT 21oz center of tube: 556 gF


Bike, DT Aerobottle, 1 cm gap to ST: 534 gF


This just scratches the surface but I can give you guys my MIT undergrad thesis if you're really into this aero bottle thing.

Mark
MITAerobike
Specialized Bicycle Components
Road Engineer/Aerodynamicist

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Mark Cote
MITAerobike
Specialized Bicycle Components

Kudos not only for the data, but also the rapid response (with pictures yet!).

It's a tough one to measure for sure in a tunnel and I think it'd be really hard to measure in a field test. Like anything else, if you can barely measure it in the wind tunnel, it's a subtle drop in drag -- one of those things that could add up but not be the differentiator.

The notes about the guys not liking them for ProTour racing is valid. The small difference in drag might not be worth the chance of dropping the bottles to many people. I can see that and have heard similar reports.

Mark

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Mark Cote
MITAerobike
Specialized Bicycle Components

Just wish I had some good yaw data...we did yaw testing on this when we were prototyping (jeeze, 4 years ago now) but there was some drift in the data at MIT so it's pretty useless. That 0 deg data's from A2 this past winter.

Bottles are one of those tests that I tag onto the bike test budget...:) I can ususally only allocate an hour max to a test like this.

MC

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Mark Cote
MITAerobike
Specialized Bicycle Components

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Mark Cote
MITAerobike
Specialized Bicycle Components

In my experience, the reproducibility of field tests conducted under very low wind conditions is just a good as wind tunnel testing. You do have to wait for good weather, though, and it is a lot more time-consuming (and most importantly, doesn't tell you what is happening at non-zero yaw).

(Directed to no one in particular.)

This fits with the interpretation that the P4's bottle isn't there to reduce aerodynamic drag, but to minimize/eliminate the aero penalty you usually pay for carrying water.

For tests with a rider, yes, I totally agree with you (and have used many of your protocols). I've learned a lot from your papers -- of course from the classic Martin, Coggan, et all paper.

It's front end tests where we're looking at stuff that's small and might or might not be affected by the rider where I greatly prefer the repeatability of testing bike alone in wind tunnel. I'm spending much more time on the track (velodrome and car track) as well as on the road doing power testing these days. The tunnel is still the default as we're busy and don't have a ton of time. But the real world is where we're racing -- why not study there too.

Mark

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Mark Cote
MITAerobike
Specialized Bicycle Components

...and it also fits with my limited field testing of the Bontrager bottle on both my Soloist and P2K ;-)

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http://bikeblather.blogspot.com/

Sounds to me like you guys need to find yourself a good "halfpipe" course near the Specialized headquarters and save the time of packing everything up and going to tracks ;-)

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http://bikeblather.blogspot.com/

Oh yea, definitely agree with that....I spent more time packing bikes than I did testing them last year...bummer.

Good to hear that your and Andrew's field test results on the aero bottles have matched what we've seen.

Mark

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Mark Cote
MITAerobike
Specialized Bicycle Components

Does Specialized own any land around their headquarters? Maybe you could justify the construction of a "halfpipe" just on travel cost savings? Hehehe... :-D

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http://bikeblather.blogspot.com/

"The problem appeared to center around the team's modified carbon fiber bottle cages, which apparently wouldn't hold on to the matching aero bottles tightly enough over stage 4's occasional bumps."

This is the exact reason i only use my bottle between the bars nows. I have launched my aerobottle twice and worry about it everytime its no there. I finally said screw it and took it off. Maybe some of the other ones are better but the Adrunal is awful.

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Grant
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Proudly sponsored by Desoto Sports
Please Support CAF every little bit helps http://raceforareason.kintera.org/grantreuter

Columbia were defiantly using camelbacks. If you catch the shot of Cavendish looking back again, not only do you see George's tube hanging in front of his, but you can see Cavendish's valve attached to his chin strap. I think you can see a few others with them, but I can't find the photo online right this second.

That's what this short test was for -- to decide ST or DT for our bottle bosses. Center of ST was 567 gF (vs. 556 gF with center of DT; bare bike 537 gF; aerobottle with ST gap of 1 cm 534 gF). Most aero is in the lowest BB position on the ST.

The whole discussion of a round bottle "fairing" the ST and rear wheel seems pretty "meh" to me. It's always been best in the BB area or in the wake of the front wheel (DT) in head on testing.

Depends on the bike (as we've all heard, and some have seen a bit), but in general, DT is better for the front wheel positions these bikes have relative to the front wheel, the DT shapes we're modeling after, etc. This is definitely true on our bikes, Cervelos, etc. But I can only definitively speak for the Transition and Shiv.

Mark

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Mark Cote
MITAerobike
Specialized Bicycle Components

You have discovered that the difference between the real world and marketing hype.

1) Triathlete water bottle decision criteria: Is it dimpled, is it aero, what recent wind tunnel test indicates the most aero placement, what should I put in it, is there such a thing as too many salt tablets... and what about my bento box.

2) Pro racer water bottle decision criteria: Will I get thirsty? Where can I easily reach it while hammering out my TT? Done. All the rest is bull$hit.

you haven't been paying attention?

MIT just clued us in that they aren't using aero bottles because lack of clarity in the rules.

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Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter

why did cancellara have a bottle on his downtube in the short prologue? seemed kinda pointless..

i think EVERYONE did

I'm wondering if its required

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Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter

Yeah the prologue was what really sparked my bottle interest.....many guys didn't have one, but then again many others did like Cancellara (round on DT) and Garmin (aero on ST) did.

perhaps with his 9000watt FTP, cancellara burns through his 90minute store of glycogen in 5

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Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter

I think the amount of testing many of the teams acctually complete is considerbly lower than people may think. Back when lance and landis were on the same team, it was only lance that got to train on a his TT bike, for the rest they might get a couple of rides close to a big race.

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TWSS

No, I think it's more that, because of his 9000 watt FTP, the Tour organizers required him to have a round bottle to try and level the playing field. ;-)

The ROT is that ~45gf (or 0.1 lbf) of drag at 30mph is ~= 0.5s/km of time savings. You can do the math from there...

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20s over 40k seems inflated, but hey I would do it.

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-- Aaron Davidson

Check your math...the savings shown was more like 20gf.

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http://bikeblather.blogspot.com/

Try this link: http://dspace.mit.edu/...84539.pdf?sequence=1

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Ale Martinez
www.amtriathlon.com

Good stuff...thanks. I only wish there were some drag results in there...

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http://bikeblather.blogspot.com/

Would be nice to read Reference #3 ;-)

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Ale Martinez
www.amtriathlon.com

Thanks for your time and input on this thread. Very interesting.

Out of curiosity what's your bottle recommendation for a bike with horrible aerodynamics? (eg someone TTing on a road bike)

Thanks!

Thanks! I didn't know this was posted online but thank you for sharing it with the forum.

Man, that takes me back :)

Mark

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Mark Cote
MITAerobike
Specialized Bicycle Components

Takes you back? What? A whole 2 years??

Sheesh...youngsters... :-P

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