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Aero bottle set-up for bike racing
I've read that the straw from an aero bottle causes some measurable drag, and as a result some people are wrapping the drinking tube around the cap to keep the straw down while riding. So I went to Lowe's and bought some clear tubing to give it a try. My first thought while testing it on an actual ride was that any reduction in drag from keeping the straw down was probably lost, and most likely net drag increased, every time I had to take my right hand off the aero bars to grab the straw and stick it in my mouth. So I pitched that idea as pointless wind tunnel results without considering the impact of the rider (70% of all drag). Am I doing something wrong? Has anyone else tried moving the straw for lower drag?
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I did. I used an old camelback tube with a bite valve. It works great and I like it more than the hard tube that tends to just poke me in the eye. For me, reality is that I move that hand to bring the hard straw close enough to drink anyway ('cause I push it down so it doesn't poke me in the eye- you getting the theme here?). So any drag I lose in that motion happens either way.
Hmm, I'm getting the picture...it's a SAFETY issue. Fortunately, I don't get poked in the eye, and I don't need a hand to lift it up, so I'm thinking it is more aero to leave it as is. Anyone else toy with this concept?
I use a Nytro Speedfil bottle. I used to use a PD Aerodrink system, but I don't like the weight between my aero bars, don't like getting continually splashed and don't like worrying about losing my little yellow mesh thingy.
The Nytro Speedfil has a flexible tube with a wire (like a thin coathanger) in a neoprene sleeve. The idea is that you bend it to where it's right near your mouth...very little effort required to get a sip.
Now I know who the real tri-geeks are.
John,
I thought the same thing but saw something written by Kenyon of TTbikefit and he implied that the straw can negate any gain in the deep/aero front wheel (ie: Zipp 404) that we spend $1k on! His wife Lisbeth just did very well in Kona and keeping the straw down was mentioned as keeping her aero profile as clean as possible.
Vince
Hope all is well with everyone.
John
This line of thinking comes from an article, from about 2 years ago, out of the MIT wind tunnel, where the folks testing a variety of things concluded that the Aero Helmet was the best bang for the buck, and that cutting the straw down on the aero drink was quite similar to having an aero front wheel. I believe that there was a TriTalk podcast on the subject at one point.
The same group concluded that the Bento box improved aerodynamics, filling in the gap behind the steerer.
Mike
For your reviewing pleasure. Here are the original EN 3.0 Threads on this topic which contain summaries of the information, links to the original article, and a link to the podcast:
www.endurancenation.us/en_forums/showthread.php
www.endurancenation.us/en_forums/showthread.php
the source was the 12/19/06 Triathlete Magazine podcast. All the links I can find are broken, but if I can find a live one, I'll post it. Long straw cut to short straw was as much of an aero gain as regular wheel to racing wheel.
Mike
Darn, Nemo, you beat me to it!
BTW, the link to the podcast is broken now that competitor has redone the whole site. I'll see if I can find the podcast somewhere else.
Mike
John,
Not being a dick on your part. I like first hand data observation myself. In this case I supplied where I read the info: believe it was Lisbeth Kenyon's bike setup for Kona or her Kona experience written by Todd K.
I agree that the bento box might help aero properties as you look also at the Specialized Transition and Willier Hump in the top tube behind the steertube. I think the smartest drink option is the P4. As soon as we start to hang crap on our bikes we often negate all the aero-bells/whistles that we've paid big dollars for.
Again, the biggest issue is our own position and engine. Lieto has those nailed!
On another note: a buddy of mine just did 70.3 Champs in FL and held 25.89 mph avg. I want his engine. His name is Todd Allington and I've been trying to convert him to EN. He was noted by Matt Fitzgerald in his Kona or Bust column in the latest Tri mag. I will keep working on him. BTW: he just finished behind Coach P in CDA by 10 seconds in his first attempt. 4:20 at 70.3 is smoking.
V
Great Pic Robin. I too am waiting for that much speed from the Koolaide.
V
No reason to not save every watt you can. They are hard to come by. The drag from cylinders is as bad as it gets and the straw is also in the wind. Might as well cut it down an bit or do something else to hide it. The MIT data on the subject seems faily convincing and it makes sense.
I used flexible tubing from the hardware store as my setup. Yes, for the 2" per 15' it takes me to reach over and put the tube in my mouth, I'm not aero. But for the other 14:58 the straw is pretty much invisible to the wind.
Rich
I used to think what is the big deal about little things like a tube sticking up etc. I mean I had never been close enough to anyone in a race were a few seconds mattered. However this summer at one of my oly's I finished third, 2 seconds behind second place and on one my sprint races, it was a small race, I finished about one second in front of another guy to take the masters category. Since then I look for any free speed I can get. If it is reasonably priced I am all for it ;if not well it may just have to wait. But even as a age grouper I think it pays to pay attention to little details. That is why this forum is so great, there is no way one person could find all this information by him/herself. But throw the question out there and someone usually has the answer and a reference.
I followed Rich's example and now swear by this setup. My bigger issue was that once I got more aero I was getting hit in the face with the straw so I had to do something anyway.
To get the straw I slide my arm back in the aero bar pad, grab the straw, drink and put it back. I never come out of the aero position and just move one arm for a few seconds like Rich said.
Rich, Matt - how do you keep your straw secured in the down position? Also, I drink more frequently than once every 15 mins, but even so, my thought while testing is that the drag from moving my hand and arm off the aerobars to get the straw probably caused more drag than the tiny bit saved from having the straw down...even if I only grabbed in once every 15 mins. I doubt if there's any data on that, but that's what my instinct was telling me. I wish they would test that at MIT. r/Paul
COOL! Thanks Chris - now I can cross the Speedfill off the Christmas list and concentrate on the Garmin 310x
Not that they have a horse in that race or anything... just sayin'
here is my setup. No splash, no yellow thingy.
I use the same, though I find that if it's filled too much, water splashes out of the straw at you over bumps. Think I'm going to put a camelback bite valve on the end. Otherwise, I vastly prefer it to my Aerodrink.
Mike
I believe this depends on the shape of the headtube aero on the bike. If you have a very aero headtube already (like Cervelos have), the profile style bottle can actually be slighly slower. However, if you have more of a round head tube, or less aero headtube, the aero bottle can actually help. I've also heard it depends on a number of other factors as well, such as how high your aero bars are (i.e. stack from spacers, stem, etc plus head tube length). So I think this probably something anyone can find a way to make any setup they like test better in a wind tunnel.
All that said, I really liked having the horizontal bottle for training as it was easy but spent more time getting my body out of the aero position with that setup then I do with the profile bottle with the flexible straw.
Based on the assumption that our body position is the biggest aero drag on the bike, I decided to race with the profile bottle and keep myself aero as much as possible.
FWIW, I also used a speedfil with flexible tubing that was hidden from the air as well. This way I stayed aero while drinking infinit or water and only came out of the bars when grabing a bottle at the aid station for safetly (however filled the bottle back in the the aero bars).
attachly, I tuck the straw into the black loop that the cap of the profile design bottle makes...
@Chris G, Thanks, I have some 2010 season changes planned and will post pictures in the spring