Drag differences (watts or seconds per 40k) for different bottle set ups

I realise it’s different depending on frame and rider BUT

Are we splitting hairs with water bottle placements? What are the differences in watts or seconds in real terms between worst and best?

the only data I can recall seeing was published in 2000 (http://www.analyticcycling.com/RiderAeroStudy.html) and may be out of date. I can’t add much insight other than quoting this study that showed 2 bottles on the frame was better than 2 bottles behind the seat. I thought I had seen some more testing from John Cobb that showed a handlebar mounted bottle to be best but again I think that was based on older frame designs.

The MIT team that won the NCAA Team TT had some info in the September 2006 Bicycling! that said a bottle on the seat tube was better than a bottle on the down tube. Don’t remember what the savings was, though. That’s also the first place I was that said an aero helmet was worth more than an aero front wheel.

So if this was true, I wonder why Cervelo would have the P3C with cage bolts only on the downtube? As for “aero helmets”, they are hot, but it would be interesting to see scientific data on if they were worth it in Ironman races. Craig A. didn’t have one. Chrissy didn’t have one. They both won. Although there are likely other factors no doubt, Craig did have a behind the seat cage set up. According to some, he had the slowest set up (but obviously the best engine on that day). I’d like to see if the dehydration/heat build up from aero helmets & watt loss from slow bottle setups would come back to bite you on the marathon. There’s an MIT mission…come up with all that data. Maybe that is a job for Mythbusters.

If it is a 40K TT why the heck are you worrying about drinking anything. Not only will carrying the bottle slow you down, but taking anything will muck up your aero profile and slow you down and then when the liquid gets into you, you’ll divert bloodflow to your stomach when your legs are crying for oxygen…its lose lose lose.

Plot of riding on the drops vs riding on the tops of the bars. There is less drag riding on the drops.

Didn’t the latest study by Garmin show that you are more aero on the tops with your forearm horizontal than your arm in the drops?

If it is a 40K TT why the heck are you worrying about drinking anything

because sometimes people get thirsty and/or a dry throat at that distance. for our 40k district (state) championship at el 5500, i took a swig of water at the turnaround. during another longer tt (just shy of 40k) i also took a swig - going uphill just prior to the turnaround.

Not only will carrying the bottle slow you down

not true if you put the correct bottle in the correct location on the frame.

you’ll divert bloodflow to your stomach when your legs are crying for oxygen

really? taking a swig of water to alleviate a dry throat will starve your legs of oxygen?

Craig sat in a legal draft pack all day. Using any aero thing he did on the bike as an example of what is right, is WRONG. If you want to see the best engine, go look at Chris Lieto who rode solo for 70 miles and built up a 13 min lead. Craig just out runs everyone.

Your question varies so much from frame to frame and bottle to bottle that no one can really answer this for you. For instance, I’ve read tests that showed a round bottle on the seat tube was faster than no bottle. Buuuuut, on a truly aero frame, say a Cervelo P3, putting a bottle on the seat tube or any tube will be slower. Some frames that are not particularly aero have been show to be faster with one or both bottles. Some frames will be faster with a Profile bottle up front because their front ends are not particularly aero.
In general, your best bet is a bottle between your arms up front. The only way to know for sure is a powermeter and your own experiments.
Chad

Do you think that taking a swig of water for your dry throat will speed you up? Seriously, stick a piece of hard candy under your tongue for the 40K if you want your thoat to stay moist. That liquid is pretty much placebo effect. At least the hard candy will give you some sugar. The liquid is barely getting into your body to the extent that it has a positive impact on the event’s outcome.

Your question varies so much from frame to frame and bottle to bottle that no one can really answer this for you. For instance, I’ve read tests that showed a round bottle on the seat tube was faster than no bottle. Buuuuut, on a truly aero frame, say a Cervelo P3, putting a bottle on the seat tube or any tube will be slower. Some frames that are not particularly aero have been show to be faster with one or both bottles. Some frames will be faster with a Profile bottle up front because their front ends are not particularly aero.
In general, your best bet is a bottle between your arms up front. The only way to know for sure is a powermeter and your own experiments.
Chad
Thank you cdw and others. I understand the differences. I was just wondering if after all the different studies have been done if any figures have been bandied about regarding best v’s worst bottle placement on various frames and tests.

With regards to why I need water and why I chose 40k.

40k is a standard comparison for reference, that’s all. It is the most common distance used when other things are compared, e.g. this or that aero helmet saves 90 seconds over 40k TT etc.

I was hoping to have some figures like this or that aero bottle set up had a difference of 15 seconds over 40k on this particular frame etc.

I ride time trials and multisport events that will require me drinking. Some with just one bottle, some I’ll need two.

Hmm that is a good idea
.

Just saying Spartacus carried a water bottle for the 2009 World TT champs. LINK HERE

so craig is smarter than the rest of the field?

sounds good enough to me.

The hard candy thing works for me all the time in 10k’s and half marathons. I don’t drink for any of these events either. The 40K TT would be right in between the time for a 10K and half marathon and arguably you’d sweat a lot more in the running events. There is not a huge penalty for mild dehydration. In fact, when it comes to running or a hillclimb, as Noakes and others have speculated, the 1-2 lb loss in body weight can more than compensate for the fact that you are mildly dehydrated…for a flat TT, there is no performance gain from technically losing some mass over the event, but as a bare minimum, you aren’t slowing down by diverting blood flow to the stomach. We’re not talking about an Ironman here…we’re talking about an FTP effort…did any of you guys see any of the world hour records drinking in those events? No way.

Even if pro cyclists might drink during a sub 1 hour TT does not mean that this is the fastest way to the finish line.

Do you think that taking a swig of water for your dry throat will speed you up?

no, i think it will make your throat less dry.

Seriously, stick a piece of hard candy under your tongue

that’s a good one. but two things: 1) i didn’t say you need fluid for hydration during a 40k. 2) what kind of candy will last for 25+ minutes (i.e. to get 1/2 way through a tt)?

lastly, i don’t know about you, but if i could keep a piece of candy under my tongue during a tt then i’m not going nearly hard enough, and might as well stay home to watch tv.

one other tidbit: instead of guessing about the merits of a bottle on a bike, maybe talk to some people who’ve studied it. personally i’ve talked to a guy who runs a wind tunnel program as well as bike company engineers that tested two of their bikes w/ and w/o the right bottle on the right frame location.

Check out the Felt pro team bottle placement, they put it on the seat tube and use an aero bottle, seems to work for them. Also Alberto (Astana) had the Bonty aero bottle on the seat tube as well in the TDF. Two major teams to use as an example, so it must work, even if you never take a drink.

OK, no arguement there. If you want to use an aero bottle empty as a legal fairing to make the bike faster, then go for it.

ok dev, if you want to get snarky and twist words around every time someone defeats your comments, then go for it. alternatively, when you have close to no idea about what you’re talking about and want to press the ‘reply’ button with more nonsense, don’t go for it.

If you want to use an aero bottle empty as a legal fairing to make the bike faster, then go for it.
That’s what the bottle on the P4 is for.