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Zipper in the front or back for bike
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Kind of a basic question but I assume the zipper placed on the front of a tri-speed suit is the preferred location for aerodynamics? And zipper on the rear is more optimized for the swim?

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Re: Zipper in the front or back for bike [geoffreydean] [ In reply to ]
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geoffreydean wrote:
Kind of a basic question but I assume the zipper placed on the front of a tri-speed suit is the preferred location for aerodynamics? And zipper on the rear is more optimized for the swim?

I would think the opposite. Rear zip suits have tested for myself and Cody Beals IIRC. My theory is that the a rear zip tends to hug the back while not bunching up in the front. A front zip suit bunches up in the front when in the aero position.


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Re: Zipper in the front or back for bike [Thomas Gerlach] [ In reply to ]
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Thomas Gerlach wrote:
geoffreydean wrote:
Kind of a basic question but I assume the zipper placed on the front of a tri-speed suit is the preferred location for aerodynamics? And zipper on the rear is more optimized for the swim?


I would think the opposite. Rear zip suits have tested for myself and Cody Beals IIRC. My theory is that the a rear zip tends to hug the back while not bunching up in the front. A front zip suit bunches up in the front when in the aero position.

Both air and water are fluids. One is just denser than the other, but the basics of how how they slow us down should be similar. Aside from the bunching there should be a higher pressure against the cloth on the front than the back of the athlete (in the case of swimming the back is not totally submerged in the fluid, the front is, in the case of biking the front is directly hit by higher pressure air no matter how aero the athlete gets unless the athlete can completely close the airflow to the chest (David Zabriskie style, but that is almost no one). Now having established that, when the fluid hits the front of the athlete with higher pressure, having a zipper there has the discontinuity in through which the fluid can flow. You don't want fluid flowing between the suit and skin. You want the fluid just compressing the suit to the skin, but mainly staying on top and not getting under the suit and flowing between suit and skin. If you could paint on a fabric suit and glue it to the skin that would be ideal but you can't so you want the fabric to stay "glued" to the body with pressure from the external fluid. Once you have fluid flowing both on top and under fabric, then its a parachute.

I THINK you could make a skinsuit where there is no bunching at the front due to the zipper, but you still have flow through the zipper and fluid getting under the fabric via the zipper.
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Re: Zipper in the front or back for bike [devashish_paul] [ In reply to ]
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devashish_paul wrote:
Thomas Gerlach wrote:
geoffreydean wrote:
Kind of a basic question but I assume the zipper placed on the front of a tri-speed suit is the preferred location for aerodynamics? And zipper on the rear is more optimized for the swim?


I would think the opposite. Rear zip suits have tested for myself and Cody Beals IIRC. My theory is that the a rear zip tends to hug the back while not bunching up in the front. A front zip suit bunches up in the front when in the aero position.


Both air and water are fluids. One is just denser than the other, but the basics of how how they slow us down should be similar. Aside from the bunching there should be a higher pressure against the cloth on the front than the back of the athlete (in the case of swimming the back is not totally submerged in the fluid, the front is, in the case of biking the front is directly hit by higher pressure air no matter how aero the athlete gets unless the athlete can completely close the airflow to the chest (David Zabriskie style, but that is almost no one). Now having established that, when the fluid hits the front of the athlete with higher pressure, having a zipper there has the discontinuity in through which the fluid can flow. You don't want fluid flowing between the suit and skin. You want the fluid just compressing the suit to the skin, but mainly staying on top and not getting under the suit and flowing between suit and skin. If you could paint on a fabric suit and glue it to the skin that would be ideal but you can't so you want the fabric to stay "glued" to the body with pressure from the external fluid. Once you have fluid flowing both on top and under fabric, then its a parachute.

I THINK you could make a skinsuit where there is no bunching at the front due to the zipper, but you still have flow through the zipper and fluid getting under the fabric via the zipper.

I don't know enough about garment design but given we bend forward, that tightens things in the back and the reverse happens in the front, I am no sure how simple it is. I use this trick when pulling up the wetsuit too, I bend forward at the waist and pull up the slack then to get the wetsuit in an even higher position.


Save: $20 on Air Relax Recovery Boots| $100 on Normatec| 15% on The Most Absorbable Magnesium | Best $50 Indoor Cycling Desk

Blogs: Q2 Blood Test Results | 10 WETSUIT buying tips | Why Latex Bikes Tubes | Vittoria Corsa Speed Aero Data | Best Cheap Aero Sunglasses | 10 Reasons To Consider HED JET+
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