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Re: the hierarchy of aero [cmscat50] [ In reply to ]
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cmscat50 wrote:
Can you point out key differences between the Pearl Tri Octane suit and a skin suit? It looks like they are close to one in the same.

It's tri-specific, so seems to be more comfortable to run in.

All clothing is dependent on how it fits you, but I believe the next big revolution in aero is clothing, likely custom fitted.

To answer someone else's question, the Tri Octane has measured to about 5 minutes over the course of an Ironman vs a fairly typical sleeveless two-piece "club" tri suit. In the end, though, you need to cover your skin with as few wrinkles as possible, and you need textured fabric to act as a boundary layer trip for your upper arms.

Jackmott is correct about tires/Crr, and I would add how those tires interact with specific wheels.

The scariest thing to put on yourself are booties. Talk about personal...they make helmets easy to figure out! Most seem to be very bad, though we tested some Castelli's last week that worked very well for the client. When they're slow, they're really slow. Shocking, actually.

Lanierb - wow, thanks, that flattering coming from someone like you.

Okay, clients are coming in for the day. I'm off the grid until tonight, but I'll try to check in. Sorry.

Jim Manton / ERO Sports
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Re: the hierarchy of aero [Jim@EROsports] [ In reply to ]
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Jim@EROsports wrote:

To answer someone else's question, the Tri Octane has measured to about 5 minutes over the course of an Ironman vs a fairly typical sleeveless two-piece "club" tri suit. In the end, though, you need to cover your skin with as few wrinkles as possible, and you need textured fabric to act as a boundary layer trip for your upper arms.

Thanks Jim! That is actually really exactly what I was looking for, just a reference point. Not sure when I'll be at the point where I even consider one but good to know, a big bearded guy in a skinsuit is making me chuckle though.

Has anyone tested stretched ears? what about tunnels vs plugs? :) (obviously doesn't matter since most aero helmets cover your ears just one of this things I think about)
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Re: the hierarchy of aero [Jim@EROsports] [ In reply to ]
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Jim@EROsports wrote:
The scariest thing to put on yourself are booties. Talk about personal...they make helmets easy to figure out! Most seem to be very bad, though we tested some Castelli's last week that worked very well for the client. When they're slow, they're really slow. Shocking, actually.

As always, thanks for chiming in, Jim.

I think this has been asked before, but I don't remember if you ever replied. Have you only tested (breathable) lycra shoe covers or also the PU-coated (non-breathable) ones? It's been assumed for a while that the lycra ones are no good, while the PU-coated ones might be good. Also, a tight fit around the ankle is likely pretty important, too.

Which Castelli ones did you test with good results on the client? Their dimpled 'Aero Race' (and lycra, I think) or their PU-coated 'Nano'?

Thanks for the info on the Champ-Sys skinsuit, will have an eye out for that one. So we're down to Castelli and the coming Champ-Sys being good, while I would think the new Bioracer could also be pretty good since they claim to have spent a lot of hours in the wind tunnel developing it and they seem to get the idea, as you suggest with the arms, to roughen up the fabric on the arms and shoulders while keeping it smoother further down the body. I have no data on it, though, only conjecture! But Tony Martin and Sky is racing in it so clearly it can be fast :p
Last edited by: MTM: Aug 23, 13 13:03
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Re: the hierarchy of aero [MTM] [ In reply to ]
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ah yes I know just the pic you're thinking of lol


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Re: the hierarchy of aero [Jim@EROsports] [ In reply to ]
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Jim@EROsports wrote:

  1. Position
  2. Clothing
  3. Helmet or Wheels
  4. Helmet or Wheels
  5. Clean front end (i.e.cables)
  6. Proper hydration setup
  7. Frame

I'm often surprised that people ignore clothing as a potential area for improvement. Some of my very first field tests were done with a constant position so I could nail down the calculations and protocols but my jerseys and shorts would change depending on the status of my laundry hamper. At first I thought there was something wrong with my calculations because I was getting huge differences in my estimated CdA. After a while I figured out that I was picking up differences in the jerseys. Whether the zipper is all the way up or part way down can be also pretty easy to see.
Last edited by: RChung: Aug 23, 13 15:46
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Re: the hierarchy of aero [RChung] [ In reply to ]
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Chung I always do my field tests with a skin suit for that reason.

I'm still not good at field tests though =)

RChung wrote:
Jim@EROsports wrote:

  1. Position
  2. Clothing
  3. Helmet or Wheels
  4. Helmet or Wheels
  5. Clean front end (i.e.cables)
  6. Proper hydration setup
  7. Frame

I'm often surprised that people ignore clothing as a potential area for improvement. Some of my very first field tests were done with a constant position so I could nail down the calculations and protocols but my jerseys and shorts would change depending on the status of my laundry hamper. At first I thought there was something wrong with my calculations because I was getting huge differences in my estimated CdA. After a while I figured out that I was picking up differences in the jerseys. Whether the zipper is all the way up or part way down can be also pretty easy to see.



Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter
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Re: the hierarchy of aero [jackmott] [ In reply to ]
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jackmott wrote:
Chung I always do my field tests with a skin suit for that reason.
Well, that's cuz you've bought into the idea and usefulness of field tests. When I first started doing them, especially on the kinds of venues I was using, I thought it was kind of a parlor trick.

Quote:
I'm still not good at field tests though =)
Me neither. You should hear about some of my field testing failures. Tom A. is pretty good at it, though. Damn him.
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Re: the hierarchy of aero [scofflaw] [ In reply to ]
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Hello scofflaw and All,

Here is some more info:

http://www.view-speed.com/time_saved.html

Cheers,

Neal

+1 mph Faster
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Re: the hierarchy of aero [Jim@EROsports] [ In reply to ]
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Great to hear the thoughts from someone with a lot of experience in the wind tunnel!

Booties is the same as socks, right? I am Norwegian and av never heard the word before and google translate translated it to socks but I did not see a lot of socks pictures when I googled the word.

How about compression calfs? Have any experience with that?

Beeing a couple of hours in the R J Mitchell wind tunnel in Southampton was a revelation for me and extremely interesting. Unfortunately my triathlon clothing was not available when I went so I could not compare it to a skin suit etc.

But I agree with you that aero clothing is the new "big thing", and I think the general focus on aerodynamics is going to be increased a lot.

http://www.triallan.com
Ambassador of:
Quintana Roo - https://quintanarootri.com
Bioracer
Precision Fuel & Hydration
Last edited by: Allanhov: Aug 23, 13 19:31
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Re: the hierarchy of aero [Jim@EROsports] [ In reply to ]
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Jim@EROsports wrote:
  1. Position
  2. Clothing
  3. Helmet or Wheels
  4. Helmet or Wheels
  5. Clean front end (i.e.cables)
  6. Proper hydration setup
  7. Frame
Castelli Body Paint II seems to be very consistently fast. Champion Systems is coming out with a VERY good skin suit. For tri, you're giving up minutes if you're not using a Pearl Izumi Tri Octane. Seriously, that suit is amazing.

After seeing the PI octane up close, I'd have to say that I would only consider it for wetsuit legal racing.
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Re: the hierarchy of aero [Allanhov] [ In reply to ]
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Booties is the same as socks, right? I am Norwegian and av never heard the word before and google translate translated it to socks but I did not see a lot of socks pictures when I googled the

Booties are overshoes - google "cycling booties", can be used for warmth or waterproofing, also for drag reduction for time trialling.
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Re: the hierarchy of aero [nealhe] [ In reply to ]
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When it comes to the hierarchy I will agree with most of the other on this forum.

1. Bike position (the biggest single aerodynamic factor by far)
2. Clothing or TT-helmet
3. Clothing or TT-helmet

I did not test any low profil wheels, but did not find a big differance in Zipp 808 rear and Zipp Sub 9 disk. About 20 g in both 0 and 7,5 degrees yaw.

When it came to helmets I found big differance between different TT-helmets. Compared with the best TT-helmet the worst produced 150 g more drag (about 6,5 % of the total drag) and a road helmet 100 g more then the worst TT-helmet. Then we got 250 g between the best TT-helmet and a road helmet (ordinary road helmet which the producer claims to have good aerodynamic to be a road helmet).

I guess you could get a 250 g difference between clothing as well, but I presume that everyone with aerodynamics in their mind at least race in tight clothing. Then again, not everyone got aero in their mind and that was pretty obvious under Norseman were we are required to wear a reflective vest on the first part of the course when we are going through tunnels. I wore a vest that was as tight I could find and gave it to my support car the second I was out of the last tunnel, but most of the people rode with over-sized vest and 20 km longer then they needed to (that was a more practical drop off point for the supporters). That observation, combined with all the horrible upright riding positions you see in a normal IM, is the evidence that aerodynamics is not on the top priority list of most of the triathletes.

http://www.triallan.com
Ambassador of:
Quintana Roo - https://quintanarootri.com
Bioracer
Precision Fuel & Hydration
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Re: the hierarchy of aero [nickag] [ In reply to ]
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nickag wrote:

Booties is the same as socks, right? I am Norwegian and av never heard the word before and google translate translated it to socks but I did not see a lot of socks pictures when I googled the

Booties are overshoes - google "cycling booties", can be used for warmth or waterproofing, also for drag reduction for time trialling.

That explains everything. I am used to the term shoe cover for that.

http://www.triallan.com
Ambassador of:
Quintana Roo - https://quintanarootri.com
Bioracer
Precision Fuel & Hydration
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Re: the hierarchy of aero [Jim@EROsports] [ In reply to ]
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Hi Jim,

Very interesting reading your results on shoe covers / booties ! Can the same happen with gloves ?

For the Tri Octane suite, we discussed it on another topic but for me the upper body material is not elastic enough and then I don't run well in it. So any time made with the suit on the bike is lost in the run !
Have you ever had an athlete tested with the Skinfit suit + shoe cover combo : this one. I haven't got one yet, but I did try it on and the material seems a lot more flexible than the Octane material is.

How much of a difference do you see from adding the arms on a high end tri-suit... meaning if you take the fastest sleeveless tri suit and compare it to the fastest tri suit with sleeves ? Also curious about 1 piece VS 2 pieces suits, if you take the compare the same model tri suit in 1 piece and in 2 pieces ???

I definitely need to get in touch with you and stop by for some testing time with you next time I'll be in the US !!!

EDIT : I saw on your facebook you tested the Skinfit suit at least once with a pro ;-)
Last edited by: pyf: Aug 23, 13 23:04
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Re: the hierarchy of aero [scofflaw] [ In reply to ]
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Let me test everyone's attention span...

Position is obviously where an athlete can find the most significant gains, but it's also important because it effects virtually everything else.
  • Your position will effect how a helmet may, or may not, work for you.
  • Your position will effect how clothing fits you.
  • Your position will effect the front end of the bike; not only with the setup to attain your position, but also how your body interacts with the airflow around the equipment.
To worry about any other item on the list (wheels/tires would be the exception) is, for the most part, a waste of time until your position is dialed biomechanically and aerodynamically. And, let me tell you, you can really go deep here; the complexities can drive you mad, and I'm sure my wife could present an argument that they've already taken me down the road to being a window-licker on the short bus (I know that's so very wrong - I'm sure I've insulted someone). Let me give you an example (of the complexities, not my mental state):


Let's get back to shoes covers (booties). We're going to have to assume a few things with this scenario, so just roll with me on this for the sake of making my point, and don't get too picky.

Let's say an athlete tests a set of shoe covers and sees a decrease in CdA. For the next run, I decide I want to lower the athlete's seat position by 1cm because i believe there's too much knee extension at dead bottom center. Let's assume I'm able to keep all else equal by adjusting for drop, reach, etc. - heck, I'll even say we changed crank length to normalize for flexion of the knee at the top of the pedal stroke. In fact, we'll suspend belief for a moment and state that the only change resulting from the saddle height adjustment was the knee angle AND the angle of the foot at dead bottom center, which measured a drop in the heel of about 3 degrees (not uncommon). We conduct our next run and see that CdA has risen. Disappoinment. Why would it get worse of all else was equal? Well, I could make an argument that the increased drag was a result of the change in foot angle and, therefore, a change in how the shoe covers fit. Could a simple change in foot angle result in an increase (or decrease) in CdA? Certainly, we see the smallest of seemingly innocuous adjustments have an effect on CdA all the time.

My point is this. Change your position, and you change how you interact with your bike, clothing, helmet, etc. If we were to create a true hierarchy for aero, it might look something like this:
  1. Position
  2. Position
  3. Position
  4. Position
  5. Position
  6. Clothing
  7. Helmet or wheels/tires
  8. Helmet or wheels/tires
  9. Clean front end (this could include aero bars, which may result in moving up this list quite dramatically depending on initial setup)
  10. Hydration/Food setup
  11. Frame
Dial in the position first, and don't make the mistake of assuming lower is always better. Once complete, you'll get better results testing everything and anything you want to put on the list.


Look, I could answer questions all day long about which skin suit is quicker than another, which is the faster bta setup; have I tested this, have I tested that. I get it, the information is addictive. In the end, and yes I know it gets old hearing it, but in the end it's all very personal. Your result may or, really, certainly WILL vary. I hope this helps.

Jim Manton / ERO Sports
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Re: the hierarchy of aero [Jim@EROsports] [ In reply to ]
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Jim@EROsports wrote:

My point is this. Change your position, and you change how you interact with your bike, clothing, helmet, etc. If we were to create a true hierarchy for aero, it might look something like this:
  1. Position
  2. Position
  3. Position
  4. Position
  5. Position
  6. Clothing
  7. Helmet or wheels/tires
  8. Helmet or wheels/tires
  9. Clean front end (this could include aero bars, which may result in moving up this list quite dramatically depending on initial setup)
  10. Hydration/Food setup
  11. Frame


Long ago one of my professors described the feudal system like this: "First, you have royalty: Kings, dukes, earls, barons. Then you have wealthy merchants. Then freemen. Then there's nothing. There's nothing; and yet a third time, there's nothing. Then you have the serfs."
Last edited by: RChung: Aug 24, 13 4:26
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Re: the hierarchy of aero [Nick_Barkley] [ In reply to ]
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I know at IM races you're not allowed to have your shoulders covered for a non-wetsuit swim anyway. I'm would imagine USAT would have a similar rule, but I'm not sure.
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Re: the hierarchy of aero [RChung] [ In reply to ]
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I think it could be argued that an area we forget when we talk about drag is body shape rather than body position[/img]. Ten, five or even two pounds of body fat is certainly bigger than most components being discussed. If you took a look at what ten pounds of fat looks like, it's pretty huge.....the wind would see it all. I have no data, but I think most of us would reduce our cda more by losing five pounds in comparison to new booties.
Last edited by: aries33: Aug 24, 13 5:51
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Re: the hierarchy of aero [aries33] [ In reply to ]
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Getting fatter often/sometimes reduces drag.

WEIRD

However from a triathlon perspective yes, losing 5lbs would gain you a lot speed...on the run..for many people.

But, you can lose 5lbs *and* slam that stem.


aries33 wrote:
I think it could be argued that an area we forget when we talk about drag is body shape rather than body position[/img]. Ten, five or even two pounds of body fat is certainly bigger than most components being discussed. If you took a look at what ten pounds of fat looks like, it's pretty huge.....the wind would see it all. I have no data, but I think most of us would reduce our cda more by losing five pounds in comparison to new booties.



Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter
Last edited by: jackmott: Aug 24, 13 5:57
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Re: the hierarchy of aero [dmorris] [ In reply to ]
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dmorris wrote:
I know at IM races you're not allowed to have your shoulders covered for a non-wetsuit swim anyway. I'm would imagine USAT would have a similar rule, but I'm not sure.


This is an excellent point and its come up a few times with elites looking primarily at Kona.

A suit like the Tri Octane might save 4 minutes over an athlete's normal clothing setup, but taking the time to change into it in T1 will eat up some of that advantage, lets say half. Okay, well, you're still two minutes faster overall, right? Not really. While you're spending the extra time in transition, your fellow competitors are rolling up the road ahead of you, so now you're playing catch up.

An elite would prefer to skip all of that because, for them, they don't see this as a means to get ahead of everyone by two minutes, they see it as a way to use less energy to stay with the group. Mentally, coming out of transition a few minutes later than everyone else is defeating and not worth the extra energy they'd use catching up early on in the bike leg.

Does "staying with the group" equate to staying in the draft, even at legal distances? Of course it does. That's the reality - especially at Kona. It's all about economy of effort 'cause we all know you win it on the run.

Poor swimmer? That's a different story. Now it might be worth the extra time because it will be easier, over the entire course, to reel in the group ahead. So, for instance, if Heather Jackson switches to Ironman distance she and I are having this discussion because she gives up significant time in the swim. For someone like her, the benefit is important.

Jim Manton / ERO Sports
Last edited by: Jim@EROsports: Aug 24, 13 6:03
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Re: the hierarchy of aero [aries33] [ In reply to ]
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I might argue that it depends where the fat is coming off and where the muscle is put on. Big shoulders create a lot of drag in aero. Then again, at 6'2", 230'ish, I'm pretty sure my CdA would decrease dramatically if I were to drop down to racing weight because, trust me, it ain't muscle that's causing that weight! :-)

Jim Manton / ERO Sports
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Re: the hierarchy of aero [Jim@EROsports] [ In reply to ]
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Jim@EROsports wrote:
  1. Position
  2. Clothing
  3. Helmet or Wheels
  4. Helmet or Wheels
  5. Clean front end (i.e.cables)
  6. Proper hydration setup
  7. Frame
Castelli Body Paint II seems to be very consistently fast. Champion Systems is coming out with a VERY good skin suit.
For tri, you're giving up minutes if you're not using a Pearl Izumi Tri Octane. Seriously, that suit is amazing.

OK - you have my attention.

A tri suit with sleeves? Wouldn't that suck, royal, during the swim??
I made that mistake, once - once.
Wore a LG top (supposedly Tri) with sleeves for Timberman, and it chafed the ever-livin' F out of my arms and pits.


float , hammer , and jog

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Re: the hierarchy of aero [Murphy'sLaw] [ In reply to ]
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Re: the hierarchy of aero [jackmott] [ In reply to ]
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jackmott wrote:
interesting, my pits chafe more if I don't wear sleeves...

Body glide on the lats*. Problem solved.

* from mid-tricep, to the bottom of the lats, on the outside edge (not like deodorant)

Your current solution, of not racing tris at all, probably works well too. ;-)


float , hammer , and jog

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Re: the hierarchy of aero [Jim@EROsports] [ In reply to ]
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A suit like the Tri Octane might save 4 minutes over an athlete's normal clothing setup, but taking the time to change into it in T1 will eat up some of that advantage, lets say half. Okay, well, you're still two minutes faster overall, right? Not really. While you're spending the extra time in transition, your fellow competitors are rolling up the road ahead of you, so now you're playing catch up.

An elite would prefer to skip all of that because, for them, they don't see this as a means to get ahead of everyone by two minutes, they see it as a way to use less energy to stay with the group. Mentally, coming out of transition a few minutes later than everyone else is defeating and not worth the extra energy they'd use catching up early on in the bike leg//

I'll agree with the tactics that are in play for the pros here but I will challenge you on the 4 minutes of savings with a different suit. One thing that gets left out of the discussion very often is what are you comparing against. I know you said what you tested against but that is not what the pros use as an alternative. Take a look at what ironman pros at the front are using and now we can make a fair comparison. This happens in swimming a lot, how much the swim skin gives you. Well it is a lot if you compare it against an unshaved person in a training suit. Same for wheels, if you are comparing against a 36 spoke cross 3 flat rim, you get big numbers. But no one uses those so it is not really a good test. What you need to look at is the minute differences between what you think is best against what athletes actually use in race situations. I do not believe that any thing you can wear as a suit will give 4 minutes over a very tight fitting tri suit.

I agree with you sentiment about body position affecting everything down the line though. Behind the seat aero bottle holders, great until you actually have to take a drink from them. Lots of stuff to think about..
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