# Skinsuit more aerodynamic benefits than aero frame?



## aclinjury (Sep 12, 2011)

I know I'm about to open a can of worms here. But, I'm wondering what are the realworld experiences out there regarding the use of skinsuit versus aero frame. Note, when I say "aero frame", I mean to compare it to both aero road frames and aero timetrial frames.

No doubt the skinsuit will probably be the best bang for the bux here. But I'm also interested in knowing the outright wattage saved between these skinsuit and frame too. Now, aerodynamic is quite an individualize thing due to the complexity of airflows. That's why would like to hear real world experiences, and not just wind tunnel reports (because nobody races in a wind tunnel).

so please share your experiences, because I'm thinking about investing in a skinsuit


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## MMsRepBike (Apr 1, 2014)

There is no real answer to your question because we're all so different.

With the same frame, same skin suit, same wattage per kilo, Cav will destroy Renshaw 10 out of 10 times. Match Cav vs. Kittel in the same battle and Kittel wins 9 out of 10 times, just ask Cav about it, he's been ranting recently.

Cav has a superior position. Kittel has the superior size/power. 

If this was 10 years ago or so with no skin suits, Cav would probably own Kittel too. But seeing how Kittel is so much bigger than Cav, a skinsuit saves Kittel much, much more. Again, Cav has spoken about this openly.

So. If you're bigger a skinsuit is more effective than if you're smaller. Easy to understand really. Frames don't matter much at all. They're very far down the list. They're below position, clothing, wheels, helmet and bike setup. The frame might even be below a proper front cockpit. I'd actually be willing to bet that the vast majority of frame drag is from the front cockpit and not the actual frame itself.

My opinion: Aero frames mean **** all. If you want to be aero it's all about position, fit and clothing. Just cleaning up your shoulder area on your jersey and making that skin tight will save an average of 20 watts as per a Castelli engineer.


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## woodys737 (Dec 31, 2005)

Felt F frame with Sram Red and Enve wheels with conti 4000 tires compared to Felt AR with Sram Red, same wheels and tires and the same power meter=Felt AR faster by maybe 0.2mph. The bikes have exactly the same setback, saddle height and reach. Same saddles. So just a guess but that's less than 10W. 5 perhaps but I'm not really able to nat ass it that close.

The speed advantage from the road bikes to my TT bike with the same wheels, tires and power meter is considerably larger. More than 1mph but, probably less than 2mph at threshold wattage. Just going from memory here. If I have time I'll check it more closely later today.

All that ^^^ is with the same clothing. More or less your average kit. I've not taken the time to examine the difference between the 3 bikes with a speedsuit. All I can say is a well fitting speedsuit (on me) has much less flapping material so it is more aero. Just can't put a number on it. If I could give some advise on the speedsuit...they are not all created the same. Take your time with this and buy one that really fits well in position on the bike. More and more companies are making better suits with textured material, longer/aero arms, better pads and even super tight pockets in the back so you can use it for road races etc...


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## Bridgey (Mar 26, 2003)

Given the skinsuit probably offers the greatest aero advantage (equipment wise), I'd like to know the difference between a Castelli Skin Suit with a nice tight pair of knicks and a $30 well fitting stock long sleeve exercise compression top that you can buy from just about any exercise department store rack. 

I don't have the money for a skin suit so basically do this. Feels like I am a whole lot more aero and the material looks much the same as on my friends skin suit.


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## Alex_Simmons/RST (Jan 12, 2008)

It all matters. I test cyclist's aerodynamics for a living.

Part of the benefit of aero frame design is the frame's shape (of which there are many good ones now) but it's more to do with the way cables are removed from the airflow and brakes and other design elements are more integrated and aerodynamic. It does make a difference, but the cost is relatively high if you are purchasing outright new/upgrading. The cost equation is different if you are only considering the difference in price of a regular frame with a specialist aero one.

Obviously there is massive difference between road and TT bike aerodynamics.

As has been mentioned, position is key, so an aero frame must also enable you to attain an good sustainable aero position. What that is depends on the type of riding you are doing. Road aero positioning is different to track pursuit aero to road TT aero to Ironman aero.

People can also learn to ride with much more aero position simply by modifying their body shape on the bike, with no change to the bike's set up. The gains from this alone are typically greater than any other single change I test.

Aside from position, skinsuits and helmets are excellent aero gains for your buck, however you need to choose wisely as which is optimal for you is individual.

Not all skinsuits are equal, I have seen 15-20W differences between _skinsuits_. The very best are very tight and use specialist aero materials and design elements that reduce drag (strategic seam placement for instance). In general, skin is slow compared with the best materials, however a poorly made or fitted suit would be worse.

Helmets are quite individual and there is no one helmet that is best for everyone. It also depends on how good or otherwise your position is. Optimal helmet choice can vary with position. Of course with helmets there are other factors to consider like comfort, visibility, cooling etc.

Be careful with booties. Some worsen aero, most do nothing. There are only a couple I have seen that improve aerodynamics.


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## spade2you (May 12, 2009)

I have accumulated a few skin suits over the years. I have some Garneau, Voler, and Squadra skin suits that have a "special" texture. It's hard to prove anything, but I have set my fastest times when wearing the textured skin suits. My power is generally very consistent, so it could be a component of weather/wind.


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## woodys737 (Dec 31, 2005)

Bridgey said:


> Given the skinsuit probably offers the greatest aero advantage (equipment wise), I'd like to know the difference between a Castelli Skin Suit with a nice tight pair of knicks and a $30 well fitting stock long sleeve exercise compression top that you can buy from just about any exercise department store rack.
> 
> I don't have the money for a skin suit so basically do this. Feels like I am a whole lot more aero and the material looks much the same as on my friends skin suit.


I don't think anyone but you can answer that (dif between castelli suit and knicks/compression top) mainly because in my experience the fit of clothes and how aero they are is incredibly personal. Further, the difference between my stupid expensive Vie13 speedsuit and a nice aero style kit has been virtually impossible to measure. The aero kit is top shelf and race tight so, unless I'm in a tunnel or inside on a track any speed difference is just noise. 

I guess my point is if you have a nice aero kit just use that. If your kit is more a club kit and has a bit of material flapping and doesn't fit in general then yeah I bet your idea would be faster.


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## pedalbiker (Nov 23, 2014)

Get the skinsuit. 150 bucks or so? That's a no brainer. 

I got a long sleeve skinsuit on ebay for 27 bucks. Very fast.


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## pedalbiker (Nov 23, 2014)

woodys737 said:


> The speed advantage from the road bikes to my TT bike with the same wheels, tires and power meter is considerably larger. More than 1mph but, probably less than 2mph at threshold wattage. Just going from memory here. If I have time I'll check it more closely later today.


Seriously? Wow. I see 4-5 mph difference most of the time (compared to riding on hoods with slightly bent elbows). Most of that is due to the position difference, of course, but wow, if the difference is that low then I'd seriously start trying to get more aggressive on the tt bike.


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## Bridgey (Mar 26, 2003)

pedalbiker said:


> Seriously? Wow. I see 4-5 mph difference most of the time (compared to riding on hoods with slightly bent elbows). Most of that is due to the position difference, of course, but wow, if the difference is that low then I'd seriously start trying to get more aggressive on the tt bike.


What I don't understand is why people don't set their road bikes up a bit more like their TT bike in order to have a more aero position. Move the seat forward to 5cm behind the BB, lower the handlebars so that the back is flat in the sphinx position, deep drop handlebars so that even with their arms straight they are still fairly flat (we tend to straighten our arms over time as they get tired), shorter cranks so that in the flat position the leg isn't hitting the lower ribs, this will still allow them to ride in a comfy position on the flats and hoods when needed.


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## aclinjury (Sep 12, 2011)

Alex_Simmons/RST said:


> It all matters. I test cyclist's aerodynamics for a living.
> 
> Part of the benefit of aero frame design is the frame's shape (of which there are many good ones now) but it's more to do with the way cables are removed from the airflow and brakes and other design elements are more integrated and aerodynamic. It does make a difference, but the cost is relatively high if you are purchasing outright new/upgrading. The cost equation is different if you are only considering the difference in price of a regular frame with a specialist aero one.
> 
> ...


thank you for the list of advices. I appreciate your in depth.


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## aclinjury (Sep 12, 2011)

pedalbiker said:


> Get the skinsuit. 150 bucks or so? That's a no brainer.
> 
> I got a long sleeve skinsuit on ebay for 27 bucks. Very fast.


hmm that's the plan. I saw some pro team suits for under $100. Probably will get one to experiment.


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## aclinjury (Sep 12, 2011)

spade2you said:


> I have accumulated a few skin suits over the years. I have some Garneau, Voler, and Squadra skin suits that have a "special" texture. It's hard to prove anything, but I have set my fastest times when wearing the textured skin suits. My power is generally very consistent, so it could be a component of weather/wind.


i'm planning to get one of the teams ones on ebay, then let's see how it goes from there. Thank god for ebay huh.


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## woodys737 (Dec 31, 2005)

pedalbiker said:


> Seriously? Wow. I see 4-5 mph difference most of the time (compared to riding on hoods with slightly bent elbows). Most of that is due to the position difference, of course, but wow, if the difference is that low then I'd seriously start trying to get more aggressive on the tt bike.


Yes 1-2 is on the low side I guess. Yesterday going from the road to the TT was 3mph at sst intensity. I am a ****ing brick and I just suck at the whole aspect of the discipline. Really frustrating as I have put in some time in a tunnel and all to not suck so much. But, it is what it is I guess. More time on the bike...

4-5 (closer to 5) would be unreal.


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## aclinjury (Sep 12, 2011)

woodys737 said:


> Yes 1-2 is on the low side I guess. Yesterday going from the road to the TT was 3mph at sst intensity. I am a ****ing brick and I just suck at the whole aspect of the discipline. Really frustrating as I have put in some time in a tunnel and all to not suck so much. But, it is what it is I guess. More time on the bike...
> 
> 4-5 (closer to 5) would be unreal.


I know this one girl (just average) who normally can ride at 21-22 mph by herself for a few minutes at a time, but on her TT bike and skinsuit and helmet, I've cruised behind her draft touching 25mph in still air. Quite an eye opener for me. I was more like, damn! She was silk through the air, while I get to listen to a constant barage of wind hitting my jersey. Another time, I was behind a guy who's a bit porky (not too much) but he had a skinsuit on, and he fills the suit quite nicely! leaving no loose edges as his whole body just looks "roundish". Then I look at my jersey, and I saw nothing but the wind hitting me. I said to myself, I gotta try this skinsuit thing.


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## woodys737 (Dec 31, 2005)

aclinjury said:


> I know this one girl (just average) who normally can ride at 21-22 mph by herself for a few minutes at a time, but on her TT bike and skinsuit and helmet, I've cruised behind her draft touching 25mph in still air. Quite an eye opener for me. I was more like, damn! She was silk through the air, while I get to listen to a constant barage of wind hitting my jersey. Another time, I was behind a guy who's a bit porky (not too much) but he had a skinsuit on, and he fills the suit quite nicely! leaving no loose edges as his whole body just looks "roundish". Then I look at my jersey, and I saw nothing but the wind hitting me. I said to myself, I gotta try this skinsuit thing.


Just in case you missed my remarks on this...the speed gain had little to do with the speedsuit v. kit and everything to do with the bike. Matter of fact, I was a touch faster with the jersey bib combo than the speedsuit yesterday. But again, that means zero as the controls were zero. However, it drives the point home (for me at least) that these small advantages or marginal gains are really difficult to measure on the road. Together they can be noticeable but, the saving from just a frame or just a speedsuit etc...will be hard to see. My thoughts are definitely in line with Alex and if you have the money it's worth trying. Fit is very important and individual here...


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## skinewmexico (Apr 19, 2010)

A few skinsuits on sale at voler.com. Personally, I would have thought aero advantage order was helmet (according to MIT), wheels, bike, skinsuit. Have you looked at the Specialized youtube channel? Those guys have tested everything in the wind tunnel, bikes, wheels, helmets, kits, shaving, you name it.


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## asgelle (Apr 21, 2003)

skinewmexico said:


> I would have thought aero advantage order was helmet (according to MIT), ...


Even the authors know not to rely on those results.


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## doctormike (Oct 13, 2015)

I haven't noticed a difference between my speed on an aero road frame and a traditional road frame. There is a difference between my road frame and tt frames. I race in skin suits for any crit lasting less than 90 minutes. If I need a gel I will stick it in my leg gripper. Positioning will make you faster regardless of what you buy. Riding in the drops of your road bike will also make you go faster. IMO if you are buying things to make yourself faster it would go wheels, clothing (skin suit and shoe covers), frame, helmet, then parts storage.


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## Alex_Simmons/RST (Jan 12, 2008)

doctormike said:


> Positioning will make you faster regardless of what you buy.


Most definitely, provided the change results in an improvement in the ratio of sustainable power to CdA.



doctormike said:


> Riding in the drops of your road bike will also make you go faster.


Aside from sprinting or descending or other times when hands on drops for bike handling is primary, for the majority of racers on road bikes set up they way they typically are, this isn't the case, at least not in a sustainable manner.

Most can attain better aerodynamics (while producing good power) with hands on the hoods. I've been through the testing with amateurs and pro bike riders and in the vast majority of cases we can attain better aero position on the hoods.

This is to do with the bike set up of course. There are a lot of people that have bars overall set too low for them. The factor that has sizeable influence is whether one can _sustain _a position on drops with forearms horizontal. It's remarkable how few are capable of this.


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## pedalbiker (Nov 23, 2014)

Bridgey said:


> What I don't understand is why people don't set their road bikes up a bit more like their TT bike in order to have a more aero position. Move the seat forward to 5cm behind the BB, lower the handlebars so that the back is flat in the sphinx position, deep drop handlebars so that even with their arms straight they are still fairly flat (we tend to straighten our arms over time as they get tired), shorter cranks so that in the flat position the leg isn't hitting the lower ribs, this will still allow them to ride in a comfy position on the flats and hoods when needed.


Because we race in packs where aero doesn't matter much, if at all. Plus there's the up and down steep hills, around sharp turns; sprinting, tucking, in the saddle, out, flicking the bike from side to side, etc. I ride quite a bit further than 5cm behind the bb and I utilize that leverage quite a bit in certain situations.


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## dcb (Jul 21, 2008)

Alex_Simmons/RST said:


> Most can attain better aerodynamics (while producing good power) with hands on the hoods. I've been through the testing with amateurs and pro bike riders and in the vast majority of cases we can attain better aero position on the hoods


Alex - That's interesting. I was wondering if the hood position that you're talking about is like the picture of Ben Jacques-Maynes in the following link about halfway down?: https://outandaboutscs.wordpress.com/tag/competitive-cyclist-racing-team/

Also, do you think you've seen these riders produce better numbers with hands on the hoods because their bikes weren't set up properly or is it a matter of getting their forearms out of the wind in a sustainable position no matter what their set-up is?


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## Bridgey (Mar 26, 2003)

Alex_Simmons/RST said:


> Most definitely, provided the change results in an improvement in the ratio of sustainable power to CdA.
> 
> 
> 
> ...


It is difficult for most people to hold their forearms in the horizontal position for long. Plus this position also uses excess energy to do so. I use it only when I need the extra speed or hitting the front.

Why don't they set up their bars so they can go horizontal on the hoods (sphinx position) when needed, but get deeper drop bars so they are also close to a flat back in the drops with only a slight bend in their arms. If they need to get more upright to rest their back, etc then go on the hoods with straight arms or the top bar. I don't get this shallow drop craze. I understand that having bent arms is more aero, but that is what you use the hoods for.


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## spade2you (May 12, 2009)

aclinjury said:


> i'm planning to get one of the teams ones on ebay, then let's see how it goes from there. Thank god for ebay huh.


Yup. I'm really missing my old team. I used to get kits so cheap. Fortunately I stocked up. 

Keep us posted if you ever get one of those skin suits. I wish I had a track so I could eliminate the wind variable.


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## Jay Strongbow (May 8, 2010)

Bridgey said:


> What I don't understand is why people don't set their road bikes up a bit more like their TT bike in order to have a more aero position. Move the seat forward to 5cm behind the BB, lower the handlebars so that the back is flat in the sphinx position, deep drop handlebars so that even with their arms straight they are still fairly flat (we tend to straighten our arms over time as they get tired), shorter cranks so that in the flat position the leg isn't hitting the lower ribs, this will still allow them to ride in a comfy position on the flats and hoods when needed.


Not everyone has the flexibility but more prominently is that people don't use road bikes for flat short time trials so naturally wouldn't set up the same as they would for time trials.


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## aclinjury (Sep 12, 2011)

Alex_Simmons/RST said:


> Most definitely, provided the change results in an improvement in the ratio of sustainable power to CdA.
> 
> 
> 
> ...


I notice this too. I've found that in order to sustain such position, I have to have my bike setup pretty much perfectly. That is to say, I have to be able to pretty much be able to hunch over AND still be able to pedal with my hands OFF the bars or BARELY putting weight on the bars. That is saying, my weight has to be perfectly balanced on the seat while I feet are pedalling. This is the only way for me to keep my arms horizontal without them burning up (ie., fatigue at the elbows). Additional benefit here is that my whole upperbody is relaxed as I don't have to use much arms to hold it up. Took me a lot of time and experimentation and costs of trying many saddles and stems, to be able to setup such thing though. So now I have a bucket of stems of various sizes and angles!


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## aclinjury (Sep 12, 2011)

spade2you said:


> Yup. I'm really missing my old team. I used to get kits so cheap. Fortunately I stocked up.
> 
> Keep us posted if you ever get one of those skin suits. I wish I had a track so I could eliminate the wind variable.


so yesterday had a chance to wear a tight (size xs) aero jersey (not a skinsuit), put on a Giro Air Attack helmet, took my traditional road bike (with round tubes and external cablings) out for an hour of going round-and-round 1-mile industrial park loop. No stop signs. There is a light headwind and a light tailwind in opposing sections, so they sort of cancel each other out. My avg speed hovered at about 24mph, avg wattage about 220W in the still-air sections (higher in headwind, lower in tailwind section). Felt good! Felt like I was zoning all day long. Felt like I was relaxed, not gasping for air, just breathing in a regular and rhythmic nature. I don't know, just felt like I was in a zone. Maybe there was some placebo good feeling too, but good feeling. I know you're around my weight and height so just thought you'd might be interested in knowing


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## Bridgey (Mar 26, 2003)

24mph, avg wattage about 220W 

Wow that is really efficient. I need to hold close to 300W for that! But I don't fit into an XS.


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## robt57 (Jul 23, 2011)

Bridgey said:


> 24mph, avg wattage about 220W
> 
> Wow that is really efficient. I need to hold close to 300W for that! But I don't fit into an XS.


Question is do you use proportional additional watts just walking along compared to the lighter/smaller person. If that make the point...


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## Alex_Simmons/RST (Jan 12, 2008)

dcb said:


> Alex - That's interesting. I was wondering if the hood position that you're talking about is like the picture of Ben Jacques-Maynes in the following link about halfway down?: https://outandaboutscs.wordpress.com/tag/competitive-cyclist-racing-team/


Sort of but he looks a bit cramped on that bike.



dcb said:


> Also, do you think you've seen these riders produce better numbers with hands on the hoods because their bikes weren't set up properly or is it a matter of getting their forearms out of the wind in a sustainable position no matter what their set-up is?


Bike set up is a function of many factors, including the sort of bike and riding you are doing. 

On road race bikes, often the normal position set up is fine and the best aero position (while pedalling) is with hands on the hoods as it enables horizontal forearms, lowering of back and head, and enough comfort to enable some version of shrugging of shoulders and/or turtling of the head (this provides massive aero benefit, like that going from a crappy road helmet to a top end aero helmet or from standard spoked wheels to high end aero wheels).

This is the position you would adapt when attempting to establish a break, or bridge across to the break, or are leading the peleton/chase for some time, or as a team train lead out man in the final kms of a race where maintaining a high speed is desired. Obviously the sprint closer to the finish line itself is not ridden that way, I'm talking about the lead up to that point.


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## spade2you (May 12, 2009)

The last time I did 220w for more than hour was up a mountain and I felt like I was gonna die. 

I did a TT this summer averaging ~230w and 23.5mph with the Squadra skin suit and a Giro Air Attack going Merckx style. Somewhat windy and rainy that day.


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## Alex_Simmons/RST (Jan 12, 2008)

aclinjury said:


> I notice this too. I've found that in order to sustain such position, I have to have my bike setup pretty much perfectly. That is to say, I have to be able to pretty much be able to hunch over AND still be able to pedal with my hands OFF the bars or BARELY putting weight on the bars.


The hands in normal riding position on a road bike should bear very little weight. 

You should be able pedal normally and lift the hands just slightly off the bars without feeling like you going to rapidly fall forward without their support. A very slight need for hand support to prevent you falling forward when on a trainer is OK (with wheel axles in a horizontal plane), as out on the road you will get a little extra support from the wind.


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## Alex_Simmons/RST (Jan 12, 2008)

Bridgey said:


> It is difficult for most people to hold their forearms in the horizontal position for long. Plus this position also uses excess energy to do so.


It is if their bike positioning is poor (and they have reasonable fitness/flexibility).



Bridgey said:


> Why don't they set up their bars so they can go horizontal on the hoods (sphinx position) when needed, but get deeper drop bars so they are also close to a flat back in the drops with only a slight bend in their arms.


I agree. 

But one should be able to get into the aero position on the hoods and sustain it for long periods. I used to do hard tempo efforts (~93% of threshold power) for ~90 minutes like that.


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## Drew Eckhardt (Nov 11, 2009)

Bridgey said:


> 24mph, avg wattage about 220W
> 
> Wow that is really efficient. I need to hold close to 300W for that! But I don't fit into an XS.


I do wear XS aero jerseys, and 210W is only enough for me to average 20-21 MPH out and back for 1:15 - 1:20.


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## woodys737 (Dec 31, 2005)

Acl...I'm trying to improve my position on the tt bike and ran across this paper HERE. Thought I'd post it as it may help you or someone else. The study puts some numbers on different equipment gains (aero v. non-aero frame, wheels, skinsuits, helmets, etc...) and gains due to changes in position. It was centered on track cycling but, the applications to other types of cycling transfer.

edit: Wanted to add that the section talking about skinsuits was interesting. Nothing new but, interesting reading about the importance of seams, fabrics, cut and texture leaves me thinking tight, rubberized as possible and less seams=faster.


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## ColaJacket (Apr 13, 2015)

Bridgey said:


> Given the skinsuit probably offers the greatest aero advantage (equipment wise), I'd like to know the difference between a Castelli Skin Suit with a nice tight pair of knicks and a $30 well fitting stock long sleeve exercise compression top that you can buy from just about any exercise department store rack.
> 
> I don't have the money for a skin suit so basically do this. Feels like I am a whole lot more aero and the material looks much the same as on my friends skin suit.


Here's a chart that shows time savings for different aero items:










GH


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## asgelle (Apr 21, 2003)

ColaJacket said:


> Here's a chart that shows time savings for different aero items:


Given what it says about shoe covers, I'm highly skeptical of this work. Testing shows shoe covers often increase drag rather than lower it.


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## ColaJacket (Apr 13, 2015)

asgelle said:


> Given what it says about shoe covers, I'm highly skeptical of this work. Testing shows shoe covers often increase drag rather than lower it.


It may depend upon the shoe covers. I think all these things were tested in a wind tunnel. 

GH


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## Alex_Simmons/RST (Jan 12, 2008)

ColaJacket said:


> It may depend upon the shoe covers. I think all these things were tested in a wind tunnel.
> 
> GH


I've tested various booties. Most make little difference or the impact was less than the resolution of testing. Only two booties types I have tested improved aero and the occasional one makes things worse.

Most things are highly individual as to the change, and of course changes to aerodynamics from individual changes are not linearly additive.


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## woodys737 (Dec 31, 2005)

Alex_Simmons/RST said:


> I've tested various booties. Most make little difference or the impact was less than the resolution of testing. Only two booties types I have tested improved aero and the occasional one makes things worse.
> 
> Most things are highly individual as to the change, and of course changes to aerodynamics from individual changes are not linearly additive.


I just ordered some Velotoze. Please tell me those are the one cover that will save me 89W! 

Seriously, though I wonder why? Those Velotoze make everything so damn smooth compared to the shoe. Maybe it's just putting lipstick on a pig? Meaning no matter how you cut it the aeroness of the foot/lower leg is really really bad no matter how you slice it...

Edit. Found an answer in the paper i linked below. pg 68, 199... Thoughts?


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