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Alex Simmons

Where to place your bottles? Some aero data.

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Interesting! I had always known a round bottle on the down tube was bad, but didn't release how bad.

Good food for thought in that article. Cheers Alex.

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I find the so bottle results on the downtube interesting.  I remember some HED testing results that had the bottle on the downtube as the worst spot.

Did anyone expect behind the seat as about the best?

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Probably not surprising as behind the seat should be seeing pretty much no clear air.. especially if you get it nice and close to you and the seat and not have to bottle's out like xmas tree branches like most agers have..

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thought btb's might have beaten it

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From my reading it doesn't take into account the fact that you can drink from between the arms aero set up with changing position... Do you think that matters Alex?

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2 hours ago, monkie said:

From my reading it doesn't take into account the fact that you can drink from between the arms aero set up with changing position... Do you think that matters Alex?

Of course.  I assume Every time you reach behind ti get bottle you're impacting your cda..

Edited by pieman

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2 hours ago, monkie said:

From my reading it doesn't take into account the fact that you can drink from between the arms aero set up with changing position... Do you think that matters Alex?

It all adds up but I suppose it's a matter of weighting the outcome based on the time taken to drink v time spent not drinking.

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So in an Ironman you are 2 minutes better to have a 500ml bottle behind your seat than a 900 on the down tube. 

But how much harder and time is wasted sitting up to reach behind you to get out of the tt position to get the bottle out for a drink and then replacing?

maybe the good guys can stay aero but not the average athlete. 

In my opinion. 

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14 minutes ago, Peter said:

So in an Ironman you are 2 minutes better to have a 500ml bottle behind your seat than a 900 on the down tube. 

But how much harder and time is wasted sitting up to reach behind you to get out of the tt position to get the bottle out for a drink and then replacing?

maybe the good guys can stay aero but not the average athlete. 

In my opinion. 

Straight from the article:

"Placing the bottle behind the saddle is a good option for aerodynamics because of the disturbed air caused by the riders body - having the bottle on the downtube where the airflow is more consistent affects the overall aerodynamic drag more than in "dirty" air. In this instance however having the bottle between Jess' arms may encourage her to drink more than if it were out of sight behind the saddle, so worth giving up some aerodynamic penalty for greater practicality."

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I used to be able to reach behind and grab a bottle out of my bts cage without getting off of my aero bars.  I'm pretty sure I'm pretty average!

What I'd love to see is some sort of aero storage system that can mount on your bikes down tube.  That would be awesome!  I was talking to my mate about that, and he ended up buying an aero bottle then cutting it open etc to use as a spares bottle, but he has to close it up using electrical tape, so it's a bit shit really.  But the idea is great.

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The data shows how much you lose over an Ironman distance - I'd think the gains for athletes who can hold the aero position for the whole ride would far outweigh the gains from better bottle mounting 

The least aerodynamic thing on the bike is the rider - this is where the real gains are made - there are some pretty shocking set ups out there and some pretty inflexible riders 😏

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I think grabbing a BTS bottle  whilst staying aero and doing without slowing down are two different things. I passed a load of riders grabbing their BTS bottles that were fumbling to stay aero and putting them back (which seems harder than getting it out for most).  Quite a few were freewheeling, sitting up, staying aero but slowing right down.Very few of them came back past me.  

The other thing was so many people have those bottles way way out of the back of bike.

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Alex I had a thought what would be your guess of keeping a bottle in a back pocket? Would it be worse that behind the seat or better cause it becomes part of you when looking aerodynamically...

 

The other advantage I can see is in the back pocket it's much easier to access though I imagine the issue is of course comfort.

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Go Faris style

 

images (7).jpeg

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As with all these things, it's simply extra data to make an informed decision. It is more helpful to quantify the differences so one can make a better informed decision on the net impact of all the factors that matter for that particular item.

These are not either/or scenarios but rather ways to help people make a choice that is sensible for them. At least if you have the data you are making a decision based on that rather than guessing.

 

Another example is choice of helmet. A particular helmet may be the most aerodynamic choice for your particular set up but it might also be less comfortable, hotter or impact vision in some way that means there are trade offs to be made and using a more comfortable but less aero helmet is a better choice overall.

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12 hours ago, RunBrettRun said:

Alex I had a thought what would be your guess of keeping a bottle in a back pocket? Would it be worse that behind the seat or better cause it becomes part of you when looking aerodynamically...

The other advantage I can see is in the back pocket it's much easier to access though I imagine the issue is of course comfort.

With aerodynamics I've learned over the years to not rely on a guess.

But if pushed to guess, then if your position is nicely aero then behind the saddle would be better.

 

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13 hours ago, AP said:

The data shows how much you lose over an Ironman distance - I'd think the gains for athletes who can hold the aero position for the whole ride would far outweigh the gains from better bottle mounting 

The least aerodynamic thing on the bike is the rider - this is where the real gains are made - there are some pretty shocking set ups out there and some pretty inflexible riders 😏

For sure, but the impact of bidon placement applies irrespective of whether you can hold an aero position or not. Unless there is some strange form of bidon that causes people not to be able to maintain a position on their bike?

IOW there is no harm in choosing to relocate a bidon on your bike while also working on your ability to ride in a good position. These are not mutually exclusive options.

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15 minutes ago, Alex Simmons said:

With aerodynamics I've learned over the years to not rely on a guess.

But if pushed to guess, then if your position is nicely aero then behind the saddle would be better.

 

My problem with a behind the seat bottle is it will stop me from drinking.  Currently I keep spares there and have one bottle on the down tube and one BTA. If moving that bottle on the downtube could potentially save me minutes on an ironman bike then I am interested to give it a try.

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Yes, I do something similar rbr.  But I forget to drink still.  And if you remove the downtube bottle, what are you going to do with your spares??

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1 minute ago, goughy said:

Yes, I do something similar rbr.  But I forget to drink still.  And if you remove the downtube bottle, what are you going to do with your spares??

I was thinking of keeping spares where they are but adding a bottle in the back pocket.

 

 

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13 minutes ago, RunBrettRun said:

I was thinking of keeping spares where they are but adding a bottle in the back pocket.

 

 

I actually tried this in my one and only IM and the bottle got so warm so quickly it was undrinkable.  Lucky it was only water but it did mean i couldn't have water with my "fuel" for a while.. i reckon that's why i didn't KQ that year..

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Actually warm water absorbs into your body faster than cool, so you'd have hydrated quicker!

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9 minutes ago, goughy said:

Actually warm water absorbs into your body faster than cool, so you'd have hydrated quicker!

Yeah I guess I was just not mentally hard enough to drink it...

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36 minutes ago, pieman said:

I actually tried this in my one and only IM and the bottle got so warm so quickly it was undrinkable.  Lucky it was only water but it did mean i couldn't have water with my "fuel" for a while.. i reckon that's why i didn't KQ that year..

wow was it a hot race?  I do most of my rides with a bottle in my jersey pocket and it never gets warm, maybe I drink it too fast.

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