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P5X component drag details
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So, I was just reading this article from Bikeradar that discusses the effect on drag of some of the configuration options available on the P5X:

http://www.bikeradar.com/...r-triathletes-48565/

If I am reading this correctly it is saying that a BTA bottle adds 41g of drag on the P5X but this is at odds with what I understood about BTA hydration. Maybe it`s their testing protocol but would be interested to hear the views of those that understand this type of testing - is this a weird aero anomaly or is it as expected?
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Re: P5X component drag details [Behan] [ In reply to ]
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Here's what confuses me:

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The P5X equipped with Ironman storage tested an average of 15 percent (30g) more efficient than the P5

15 percent? What am I missing? Can someone explain how 30g could be 15%?

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Re: P5X component drag details [Grill] [ In reply to ]
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'Ironman storage' isn't a precise thing either; everyone is different.

29 years and counting
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Re: P5X component drag details [Behan] [ In reply to ]
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The usage of percents and grams and whatnot are incoherent at best in this article. This is a bunch of random gibberish.
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Re: P5X component drag details [Behan] [ In reply to ]
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The article starts with "Obviously, the P5X is all about aero..." then goes on to say "It may seem aero is way down the list of the P5X's attributes..."

Really? It is either obvious or its not? and it isn't obvious if it seems aero is a long way down the list.

It would appear there BTA values is without a rider.
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Re: P5X component drag details [Behan] [ In reply to ]
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Hi Behan,

The best results we have recorded in regards to BTA bottles were with live riders when they could "hug" the bottle with their forearms. Our test dummy "DZ" is amazing for consistency in the tunnel when comparing models or making small changes on the frame, however his unique hand position exposes the bottle and does result in higher drag numbers using BTA setups than with our live rider testing.

When I was used for some live rider tunnel testing, the BTA bottle consistently tested very well, being aero neutral or even slightly faster at certain yaw angles, because my arms and hands covered the bottle. Width of arms, height of bottle and hand position all have an affect on the drag of BTA setups.

In general if you need a bottle, between the arms is a great choice which is why we include mounts.

Jakub


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Re: P5X component drag details [TheJakes] [ In reply to ]
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Hi Jakub,

Can you provide feedback in regards to tunnel testing for round bottle in the down tube (without the speedcase, and also with the speedcase). Thanks
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Re: P5X component drag details [pabloarc] [ In reply to ]
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Hi Pabloarc,

The bottle with speedcase was the faster option. Let me check with our Engineers and see if I can get more details :)

Cheers.

Jakub


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Re: P5X component drag details [pabloarc] [ In reply to ]
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Hi Pabloarc,


I checked with our engineering team, seems I was wrong, sort of :)

The advantage between Speedcase + bottle vs no Speedcase + bottle is very slight but within tunnel error so we consider it a wash. This lets you choose whatever configuration you prefer without paying an aero penalty.

The Speedcase by itself is 100% aero neutral. So you can carry as much or as little "stuff" as you like or set up your DT bottle in the way that works for you.

Hope that answers your question!

Cheers.

Jakub


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Re: P5X component drag details [TheJakes] [ In reply to ]
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Thank you for the information!
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