Great video. Thank you for sharing the knowledge and boiling it down to be understandable and relatable. As is the case with many things, sometimes things that look simple really aren't.
Sweet stuff! Awesome the way you laid it out, explained it and that it was informative but to the point/short. Thanks for sharing and you have yourself a sub! Have a great day and keep pedaling! 😆🐺🚴🏼
What are your thoughts on hydration packs? It allows me to keep both hands on the bar longer when in a gravel races. Hitting washboard or other less than ideal gravel conditions one handed is no good. After watching these videos I thought maybe i could try fitting it under the jersey? Great information. Keep it coming.
How feasible is a sub 0.30 CdA on an aero road bike? Assuming you’re utilizing some marginal gains like small helmets, narrow or flared aero bars, 50mm+ wheel depth, and are flexible enough to get into a ‘better than most’ bike position?
What does it say about our educational system when we can't talk about simple math concepts. Granted aero math can go much deeper, but what Josh is showing is something a high school freshman should know
Any viewpoints on the Cda of the redesigned Cannondale Supersix? Specifically the flat handlebars, redesigned stem, lower seat stays, wider tyre clearance.
The aero bar stem setup on the new SuperSix along with the hidden cables is probably worth ~0.012-0.015 m^2 CdA, which would be ~18-20 watts at 45kph or 25 watts at 50kph. I'd guess another ~0.005 m^2 from the rest of the updates/changes and tube shaping work. From the SuperSix to something like the SystemSix you probably find another 0.010-0.015 m^2 improvement.
On the subject of spoke shape, if a wing design is used, doesn't the spoke spend roughly half it's time facing backwards? How does that affect the design?
Yes but not backward to its own wind. Because of wheel rotation, the spoke is cutting through its own wind from the same orientation. It’s complex (understatement) but it will be just slicing through less wind as it travels to the rear of the bike; more as it moves forward. (Also more wind speed on outer spoke near rim than on spoke near hub.) And Sapim X-ray spokes are symmetrical cross-sectional foil shapes in any case, not NACA wing shapes.
I had heard several people talking about getting aero helmets a size LARGER and seeing gains. It makes surface-level sense to me that a big helmet would be better in an aero tuck (breaks air over your shoulders), while a smaller helmet would be better with your head up, in the hoods, but I'd love to know if someone has more scientific insights.
For TT position with the proper 'turtle' of your head, a larger helmet can be faster, the key is getting it in front of your shoulders and laying flat on your flat back. If your head is up in the air at all, it's slower. For road positions smaller helmets are always faster.
Ron, from what we've been told, the idea is to both put the fork/seatstay in line with the centerline of the rider legs and also to minimize the venturi effect between the frame member and the wheels.. There is no camber in these frame members, so they aren't using it to turn the air from what we know..
@@SILCAVelo Dear thanks for the video. I agree with Ron. England is a step forward than the world for bike design. By doing this they are reducing the global Cda and also take lesson from previous olympic game where they add stiffness issue limiting the starts power due to lateral flexibility generate by really narrow wheels and fork coming low inertia on the front fork (check the spacing of there wheel). Some of the rider complain at last Olympic game of this issue (the ones that change fork and front wheel). By putting this fork arm and the seat stay in the way of the leg, they can use uncommon wing profile to reduce the drag on the leg that is the main power generating item. It seems that each tube of the bike can be tune to the rider weight, leg shape and profile. It is allowed by the way of producing this bike with 3d print lugs & joins and custom layed tube with carbon fiber. That is the raison why the bike take time to go out for all riders in my thinking. As reminder bike are design for inertia and constructability (this bike tackle both subject). Inertia of a square structure is bh^3/12+Sd^2 (b = breath, h =height, S = surface and d =distance to neutral axis so by making this they can also reduce weight due to Sd^2 and reduce section... Also by incresing the space they reduce the hysteris of variation of pressure... I would love to discuss with the designer of this bike. He may have just violate one pattend own by Bastion cycle. Argon design may have take the same path than what they have done for previous olympic game but limiting this factor by the shape at the bottom of the fork and rear lug. I really like your talk but as structural and bike passionate, it seems that UK find all marginal gains including lots of factors.
Can we get a video explaining the difference between aero socks and leg shaving, and why wouldn't hair on the leg make micro turbulence and create a similar effect to aero socks?
It's all about boundary layer thickness and location of the trip zone. For flow on the lower leg, the boundary layer thickness for tripping is about 1mm, and you only need it right in the separation zone, so with hairy legs you have ~1cm long hair everywhere making a big mess of the airflow. Theoretically you could leave 2 thin stripes of leg hair at ~+/-40 degrees of the center of the shin, and then keep those stripes trimes to ~1-2mm max and have a similar effect to aero socks.
@@SILCAVelorecently I started shaving my legs to prevent bib from slipping upward, so as the silicone gripper would stay put. I notice my legs are no longer slick with sweat when I stop for a break. Before, my legs would be slick with sweat. I assume this must be the wind hitting legs hair, creating turbulence, and only like half of the wind get in contact with my legs skin. So the sweat does not evaporates as quickly.
Specialized helmet is faster than no helmet.. most modern aero road helmets are and many to most modern ventilated helmets are roughly equal to bare head as you are sacrificing some additional frontal area but in exchange for slightly improved Cd
So if aero dynamics is so important and then they wear aero dynamic suits. Then why dont they make the frame look like a Golf ball with the dimples oppose to having the smooth frames that causes more drag?
Golf ball dimples only work on golf balls or other rapidly-spinning objects. Surface texture and small trip strips have been played with though, particularly where the boundary layer separation is found to occur.
@@the318pop Some of the Castelli 'aero' labeled clothing has 'reverse dimples' on some surfaces. Who knows if this actually has any measurable benefits or not??
Pro racers have worn smaller helmets ever since 'hardshells' became mandatory. They would take the old first generation Giros and ripped out all the padding and cut foam down until it fit. This is why the pros didn't look like they had a giant mushroom on their head.
@@SILCAVelo It is totally AMAZING and perplexing to me that the usually/normally Stasi-like UCI even looks the other way regarding this, let alone actually ALLOWS it!!!
When the first hard shell lids came onto the market (pretty much the original HUGE Bell lid), and only very very few ABL of A (or was it the USCF by that time??) riders wore them (a notable, and accomplished exception was Ron Skarin of U.S. National Championship Pursuit/Team Pursuit fame, and he won the Sommerville {N.J.} crit twice while wearing one). He also was one of the first in the country, and maybe even the WORLD, to ever ride a titanium frame (Teledyne), albeit a fairly crude example of that material as compared to latter top grade, Sandvik tubed builds. Us holdouts (until the USCF made them MANDATORY) still wearing our 'leather hairnets' used to say they were wearing a pregnant tortoise's shell on their heads, like in the Flinstones cartoon. 🤣
As to HOW the Pro Tour riders can actually physically wear a helmet two sizes too small for them is something you did not explain. (I always wished that I could get a helmet which fits sooooo close to my skull like theirs all seem to do, as much for the aesthetics as for the aero effects/benefits! 😉) Are they cutting away ALL of the liner padding/MIPS material, as well as a good deal of the actual foam impact absorption materials, in order to accomplish this?!? IF so, HOW on earth does the draconian UCI allow them to get away with this when they ban aero socks, as well as other even more miniscule 'marginal gain' items?? (Or, are the sponsoring helmet manufacturers custom forming helmets for every Pro Tour team rider like some of the clothing manufacturers do???)
Most of them that I know use a spoon to compress the foam on the inside of the helmet to 'customize' the fit. This method also allows all of the certification stickers and such to remain intact.. But of course, DO NOT DO THIS, it definitely makes the helmet less safe.
Great video. Thank you for sharing the knowledge and boiling it down to be understandable and relatable. As is the case with many things, sometimes things that look simple really aren't.
Thanks JR! - Josh
Sweet stuff! Awesome the way you laid it out, explained it and that it was informative but to the point/short. Thanks for sharing and you have yourself a sub! Have a great day and keep pedaling! 😆🐺🚴🏼
Fantastic video and excellent explanation. The example of the wing is superb and really brings it home. Thanks Josh.
perfect explanation - very easy to follow and use day to day in my own cycling ;)
What are your thoughts on hydration packs? It allows me to keep both hands on the bar longer when in a gravel races. Hitting washboard or other less than ideal gravel conditions one handed is no good. After watching these videos I thought maybe i could try fitting it under the jersey? Great information. Keep it coming.
How feasible is a sub 0.30 CdA on an aero road bike? Assuming you’re utilizing some marginal gains like small helmets, narrow or flared aero bars, 50mm+ wheel depth, and are flexible enough to get into a ‘better than most’ bike position?
What does it say about our educational system when we can't talk about simple math concepts. Granted aero math can go much deeper, but what Josh is showing is something a high school freshman should know
How much drag would the peak on my MTB helmet cause??? 🤷
Any viewpoints on the Cda of the redesigned Cannondale Supersix? Specifically the flat handlebars, redesigned stem, lower seat stays, wider tyre clearance.
The aero bar stem setup on the new SuperSix along with the hidden cables is probably worth ~0.012-0.015 m^2 CdA, which would be ~18-20 watts at 45kph or 25 watts at 50kph. I'd guess another ~0.005 m^2 from the rest of the updates/changes and tube shaping work. From the SuperSix to something like the SystemSix you probably find another 0.010-0.015 m^2 improvement.
On the subject of spoke shape, if a wing design is used, doesn't the spoke spend roughly half it's time facing backwards? How does that affect the design?
Yes but not backward to its own wind. Because of wheel rotation, the spoke is cutting through its own wind from the same orientation. It’s complex (understatement) but it will be just slicing through less wind as it travels to the rear of the bike; more as it moves forward. (Also more wind speed on outer spoke near rim than on spoke near hub.) And Sapim X-ray spokes are symmetrical cross-sectional foil shapes in any case, not NACA wing shapes.
I had heard several people talking about getting aero helmets a size LARGER and seeing gains. It makes surface-level sense to me that a big helmet would be better in an aero tuck (breaks air over your shoulders), while a smaller helmet would be better with your head up, in the hoods, but I'd love to know if someone has more scientific insights.
For TT position with the proper 'turtle' of your head, a larger helmet can be faster, the key is getting it in front of your shoulders and laying flat on your flat back. If your head is up in the air at all, it's slower. For road positions smaller helmets are always faster.
Old video, but would love to know how all aero helmets rank in CdA tests.
Testing a helmet in isolation will not help you to choose. The fastest helmet will depend on the individual's shape, body position and head position.
I always thought the pros looked better in their helmets than everyone else. Now I know I wasn't going crazy!
How to buy this shirt?
Is the lotus bike designed to effect airflow around a riders knee to reduce overall bike/rider drag than just the bike drag?!
Ron, from what we've been told, the idea is to both put the fork/seatstay in line with the centerline of the rider legs and also to minimize the venturi effect between the frame member and the wheels.. There is no camber in these frame members, so they aren't using it to turn the air from what we know..
@@SILCAVelo Dear thanks for the video. I agree with Ron. England is a step forward than the world for bike design. By doing this they are reducing the global Cda and also take lesson from previous olympic game where they add stiffness issue limiting the starts power due to lateral flexibility generate by really narrow wheels and fork coming low inertia on the front fork (check the spacing of there wheel). Some of the rider complain at last Olympic game of this issue (the ones that change fork and front wheel). By putting this fork arm and the seat stay in the way of the leg, they can use uncommon wing profile to reduce the drag on the leg that is the main power generating item. It seems that each tube of the bike can be tune to the rider weight, leg shape and profile. It is allowed by the way of producing this bike with 3d print lugs & joins and custom layed tube with carbon fiber. That is the raison why the bike take time to go out for all riders in my thinking. As reminder bike are design for inertia and constructability (this bike tackle both subject). Inertia of a square structure is bh^3/12+Sd^2 (b = breath, h =height, S = surface and d =distance to neutral axis so by making this they can also reduce weight due to Sd^2 and reduce section... Also by incresing the space they reduce the hysteris of variation of pressure...
I would love to discuss with the designer of this bike.
He may have just violate one pattend own by Bastion cycle.
Argon design may have take the same path than what they have done for previous olympic game but limiting this factor by the shape at the bottom of the fork and rear lug.
I really like your talk but as structural and bike passionate, it seems that UK find all marginal gains including lots of factors.
Can we get a video explaining the difference between aero socks and leg shaving, and why wouldn't hair on the leg make micro turbulence and create a similar effect to aero socks?
It's all about boundary layer thickness and location of the trip zone. For flow on the lower leg, the boundary layer thickness for tripping is about 1mm, and you only need it right in the separation zone, so with hairy legs you have ~1cm long hair everywhere making a big mess of the airflow. Theoretically you could leave 2 thin stripes of leg hair at ~+/-40 degrees of the center of the shin, and then keep those stripes trimes to ~1-2mm max and have a similar effect to aero socks.
@@SILCAVelorecently I started shaving my legs to prevent bib from slipping upward, so as the silicone gripper would stay put. I notice my legs are no longer slick with sweat when I stop for a break. Before, my legs would be slick with sweat. I assume this must be the wind hitting legs hair, creating turbulence, and only like half of the wind get in contact with my legs skin. So the sweat does not evaporates as quickly.
So what is better? Specialized helmet or no helmet at all?
Specialized helmet is faster than no helmet.. most modern aero road helmets are and many to most modern ventilated helmets are roughly equal to bare head as you are sacrificing some additional frontal area but in exchange for slightly improved Cd
So if aero dynamics is so important and then they wear aero dynamic suits. Then why dont they make the frame look like a Golf ball with the dimples oppose to having the smooth frames that causes more drag?
Golf ball dimples only work on golf balls or other rapidly-spinning objects. Surface texture and small trip strips have been played with though, particularly where the boundary layer separation is found to occur.
@@the318pop Some of the Castelli 'aero' labeled clothing has 'reverse dimples' on some surfaces.
Who knows if this actually has any measurable benefits or not??
That Silca business card looks like a small race number in most gravel races. How much do those number plates cost???
Awesome segment, learned a lot. How many watts do you recon Quinn Simmons’ beard is costing him? 😝
Likely a few! Interestingly, we tested facemasks in the tunnel and found that some of them could be as much as 10w savings at 50kph on some riders!
Wow, that’s quite interesting, thanks for sharing.
Maybe you should do a chat with hambini
Gonna go buy me a small S-Works Evade! 😉
Pro racers have worn smaller helmets ever since 'hardshells' became mandatory. They would take the old first generation Giros and ripped out all the padding and cut foam down until it fit. This is why the pros didn't look like they had a giant mushroom on their head.
Yes and yes. - Josh
Looks cooler; way less safe
@@SILCAVelo i really had no clue…!! So they’re removing all MIPS stuff and all padding to wear a smaller helmet?! Wow
@@SILCAVelo It is totally AMAZING and perplexing to me that the usually/normally Stasi-like UCI even looks the other way regarding this, let alone actually ALLOWS it!!!
When the first hard shell lids came onto the market (pretty much the original HUGE Bell lid), and only very very few ABL of A (or was it the USCF by that time??) riders wore them (a notable, and accomplished exception was Ron Skarin of U.S. National Championship Pursuit/Team Pursuit fame, and he won the Sommerville {N.J.} crit twice while wearing one).
He also was one of the first in the country, and maybe even the WORLD, to ever ride a titanium frame (Teledyne), albeit a fairly crude example of that material as compared to latter top grade, Sandvik tubed builds.
Us holdouts (until the USCF made them MANDATORY) still wearing our 'leather hairnets' used to say they were wearing a pregnant tortoise's shell on their heads, like in the Flinstones cartoon. 🤣
The James Bond episode 😉
As to HOW the Pro Tour riders can actually physically wear a helmet two sizes too small for them is something you did not explain.
(I always wished that I could get a helmet which fits sooooo close to my skull like theirs all seem to do, as much for the aesthetics as for the aero effects/benefits! 😉)
Are they cutting away ALL of the liner padding/MIPS material, as well as a good deal of the actual foam impact absorption materials, in order to accomplish this?!?
IF so, HOW on earth does the draconian UCI allow them to get away with this when they ban aero socks, as well as other even more miniscule 'marginal gain' items??
(Or, are the sponsoring helmet manufacturers custom forming helmets for every Pro Tour team rider like some of the clothing manufacturers do???)
Most of them that I know use a spoon to compress the foam on the inside of the helmet to 'customize' the fit. This method also allows all of the certification stickers and such to remain intact.. But of course, DO NOT DO THIS, it definitely makes the helmet less safe.
i prefer ac dc