A deeper haircut is the most daring aero improvement for me. The next bigger would be shaving my legs, but that would make it a hell of a deal to my spouse.
I’ve rode several handlebar fairings built 30-35 years ago: Zzipper, Breeze-Eze and AeroEdge w upper body sock for 1990 RAAM team. These had more rounded shape that the wind screen you used. I did coast-down tests in high school for physics class. The ONLY benefit I noticed was when the body sock was added. I remember my max velocity in coasting off a hill with an aero bar and no fairing was equal with the front fairing (both 21.5 mph). With the body sock it increased to 23.0 mph. In repeated one-hour runs on a rolling hill 6-mile nonstop park loop for One Hour, I noticed about a similar 1 to 1.5 mph increase from say 23.5 to 25 mph when using windscreen+ bodysock. This was 15 years ago. My name online for a longtime on recumbent forums has been Upright Mike as I was one of the few uprights competing with recumbents at human powered vehicle races. In later years, a photo of me had made it around the world several times over, being picked up website BikeSnob. I’ve been called biker in a condom, etc and got famous for adding detergent bottle /ArmorAll aero leg fairings as well.
Get a recumbent! Years ago I had four diamond frame road bikes, great ones too. Bought a recumbent and there's been no looking back. Now the happy owner of three recumbents, and a single upright. Forget about the rules backwards rules set by UCI etc. Set yourself free. And go fast!
They are not ideal for climbing, that's true. But the improved aerodynamics while on level ground, or even better when descending makes up for that 🙂 @@andreyrevyakin7272
We know that fully faired recumbent velomobiles are stunningly fast relative to a normal bike. So the question is how much of that approach can you apply to an upright bike without making it unrideable from a practical point of view. Intuitively, it seems we should be able to make significant speed gains with the right designs.
The screen was essentially a wall into the air, similar to a caravan hitting the wind. You need the screen to be curved, and probably have a shallower angle. But if we're going for all out aero, then go with a fared recumbent!
Yep, I agree, I've used it many ago and it is much more aero at speeeds @30km/h than WTF GCN you showed here whis my video: ua-cam.com/video/V4VSSuG2yFY/v-deo.html
Somehow, every time one of these pops on the market, it invariably looks as though someone paid the designer to create something as goofy and decidedly-not-aero as possible. MotoGP and gravity hpv fairings look nothing like this baby-riotshield, and probably for a reason 😂
Exactly, many people seem totally unaware that with aerodynamics, the way the air flows back together after is just as important as how you separate it in front.
Good idea guys. In motorbike racing the screens are a lot more curved. As you said, front fairings on recumbents are effective. I recall seeing, in cycling+ magazine back in the 1990s, a photo from the 1920s of a bike with a "torpele" faining (basically a tepered rear fairing made of balsa and tissue supported on legs like a carrier) that lead to a UCI ban because it made ordinary riders too fast!
I swear that there's a ton of potential in bike aero, an upright rider have as much drag as an entire car. I don't think going full 'recumbent velomobile' is the solution though, but there should be a middle ground.
The reason why the saddle bag is helping (as well as the superbike designs and, indeed, the evolutionary advantage of wasps) is because when moving forward it's not only the air that you push holding you back, but as you move through the air you create a vacuum behind you. Having a smaller surface area at the end means there's a smaller surface area to get sucked back.
Yeah not a vacuum but a region of turbulence and slightly lower pressure. The rear fairing reduces the abrupt change in cross section which delays the detachment of the flow, decreasing the size of the turbulent region. The surface area actually ends up larger but skin drag contributes less than pressure drag in front-on air flow. The reason we don't go nuts with this in non-UCI bikes is because of crosswinds as they mention.
Not a new idea, Zzipper fairings have been around for decades. Myself and a friend rode across the US with Zzipper fairings in 1983, and when we were in central California an old farmer saw them and in a country drawl said: 'Now I've seen everything, windscreens on bi-cy-cles'...
2:22 I'd love to see you guys do a video on Chung testing of aero differences. Cheaper than a wind tunnel, and more sciencey than just a stop watch around a track.
You have to recognize the aero windscreen isn’t as much of a penalty as it looks. The idea is interesting to say the least. A lot of testing and a few interesting models and configurations could end up in an interesting game changer
The wind guard (door) fairings are installed on motorcycle handlebars for comfort against strong winds. It’s not aero because you are blocking air with a plank on headwinds. But it’s comfortable for a motorcycle rider to not have strong winds blow into their face. For cyclist air blowing to your face provides cooling to your head while wearing a helmet. You’ll only feel strong wind resistance on headwinds.
A self-inflatable rear fairing of a paragliding harness. These fairings are very light, aerodynamically optimized and don't require any rigid frame. It is probably possible to mount one on a backpack (perhaps upside down because the body position is different). The most advanced rear fairings are installed on competition harnesses such as Woody Valley X-Rated 6, Niviuk Drifter (old models), Ozone Submarine, WV X-Rated 7 (new ones). Old competition harnesses have only one parachute compartment and are banned by FAI. It should be possible to find one for a nominal price.
Olly, great point about wind effect i.e. Apparent wind and wind angle (AWA) vs True wind, becuase the effect will almost always be negative. But a decent fairing on the front of the bike, and re-run please. I suspect 10% (!) and more at 0 deg AWA as thats the difference on my motorbike, any yaw won't help. My hypothesis ,Its about foils directing, not big shapes displacing.
I think a more forward mounted and oval windshield, very curved (not that plain plank of plastic used here), taller and with deflector shape at the borders could work really well. The problem will always be the crosswinds will throw out riders all the time.
I do see one advantage to the "windscreen" - commuting in the rain. I road motorcycles for over 40 yrs in all sorts of weather and a windscreen helps keep the rain from beating you to death.
I would love to see you guys try some fairings ! I had that idea in the back of my head for quite some time, even thought about using some CFD software at work to try it but never really had the time 😂
In 2012 I designed my totally custom Rohloff14 tour bike. The main feature is a shark nose CF trunk attached to the head tube, about 9L volume I guess. It also has 2 bottle mounts on the back of it to the side of the head tube. It's awesomely useful, but at best I think neutral aero. But IMO it does help to have part of the wind going around that instead of hitting me. I also made a CF pouch above the BB area. And I put a thermos with a CF lid to hold tools under the BB. It points forward and acts like a ballast tank. LOL. Works great. Also have a frame bag full time. Crosswind seems to have NO effect. The thing is 78 lbs without the tour stuff. LOL I do centuries with it LOTS. The Trans-America race rules guys sure go to EXTREME measures to expel aero. LOL. Can't even put a water bottle in front of the HT.
I have an old Mongoose DXRal bike that weighs 38.5 lbs. I ride a 5 mile road around a perimeter of a small airport near my house. In that ride, there is a stretch of half a mile that I push my MTB to the max speed. I get 15 MPH. I covered the inside frame of the bike with Glad sticky food wrap. Ran the same speed test and now I get 19 MPH. I believe it is possible to increase performance to remarkable margins with aero fairings.
It's been tested in the recumbent world that a rear fairing is realy helping more than a front fairing. It prevents the Kármán vortex street from forming and brings the air together nicely. It can actually be prevented by just a fin. This might also be why rear Disc-Wheels are so effective. Maybe you should try just building a fin behind the rider.
solid disc front wheels would be better, but steering and control in wind would go out the door. Been proven. Recumbant is already more aero, so the length of the bike is adding more disruption as the wind travels down the frame and rider. Up right the rider is half as long. two different maths.. :)
@@tonycrabtree3416 The Front disk would of course also be beneficial and I understand that it is problematic for bike control. I doubt hoever that it is more beneficial than a rear disc. Regarding the different math: Yes the Reynolds number, as well as Drag coefficient and frontal Area change and with it the amount of drag the parts create relatively. But the general effects stay the same and the Karman-vortex-street is a big producer of drag that should be avoided. Do you have any sources that show otherwise?
Regarding the sum of ground speed and headwind: while the aerodynamic force may be the same, the power lost to air resistance is not. The reason is that the drag force (in N, kgf, lbf, whatever) must be multiplied by the actual ground speed to arrive at the power in watts. Therefore, a ground speed of 30km/h and a head wind of 15 km/h generate the same force as 45 km/h but does not require as much power.
@gcntech what about chest fairings? Heard that a bottle tucked in your jersey in the front at chest area can give an aero advantage of up to 4-5%. Pls test this.
aircraft change their shape to adapt to flight. flaps are deployed for lift when landing/taking off, spoilers for more drag to slow down, and landing gear are raised to reduce drag. basically, aircraft can change shape, but bicycles can't. bicycles have gearing which can easily be changed to adapt to different cycling conditions like hills and wind. yet, it seems the aerodynamic solutions for bicyclists are rather limited, clumsy, rigid, and impractical. it might be useful if bicyclists could deploy aerodynamics that were as easy as changing gears. since, wind is often mentioned as a detriment to cycling it might be advantageous if cyclists could have an aerodynamic feature like we do with gears... or maybe, the wind isn't as much of a detriment as we are led to believe?
Hold on. Apparent wind isn't as simple as adding road speed to wind speed. We all experience how much harder it is to push into wind to maintain the same road speed. Your road speed has to drop if your power input doesn't increase to make up for the increased wind drag.
I wonder if attaching some sharp trailing edges for flow separation to your outfit could help reduce drag. I’m thinking of wedge-profile foam strips glued to the back of your upper arms and your calves. Also, increasing the size of the saddle bag at the front so that it reaches over the saddle and is the same cross-section as your bum with smooth sides and sharp trailing edges, could help.
Fyi, with a power meter and a loop with some elevation change the "virtual elevation" method implemented in Golden Peak and other cycling performance software can get you wind tunnel quality measurements of CdA and rolling resistance.
Look at the 125 cc motorcycle GP racers. They’re aerodynamic. You would need to hide the legs from the wind and to a certain degree the arms as well. That lexan wind screen was close to being useless and mounted at the handlebar a disaster waiting to happen. But if you could hid yourself from the wind, like on a motorcycle, you could pull a serious gearing and get an impressive topspeed.
Sure this wind shield will help. Or from the looks of it, just use a wooden rectangular plate and strap it to your bicycle. But always keep in mind that its surface area needs to be bigger than the rider to actually reduce air resistance.
It doesn't, it only needs to deflect air around 'messy' areas like the legs and arms to have a useful effect. But even if area is increased, remember that aerodynamic drag is Cd x area. If you can dramatically reduce Cd by smoothing the airflow then a bit of extra area may not matter.
Would love to know about the detriment (or benefit) of wearing a hydration pack vs carrying 2 bottles. I always go hydration pack just because 2 bottles isn't enough hydration for me even over a modest distance, being that I'm a profuse sweater.
There was a test on GTN (I think) that showed that the hydration pack was more aero. But 1. it needs to be in a small backpack 2. It might be very rider dependent. So ideally you personally would have to try out different packs in the wind tunnel.
If your looking for a aero fairing. Start with something like the set up on a 125cc racing motorbike. I think I have seen a this before. The crosswind was the big problem.
As to your air speeds, what about Crosswinds. The highway to my nearest town often has 50 mph crosswind. any rim depth at all is unrideable in those conditions. When I commuted it daily aero bikes weren't a thing yet, but rims were.
The best way to test this would be to accelerate up to a fixed speed (maybe with a car or bike towing you) and then to coast and measure the time to slow down to a complete stop without braking. This would eliminate human error and should be done on the same bike
In '81 Zzipper fairings sold a much cleaner lighter fairing which reduced drag considerably. If look at human powered vehicle competitions have lots of different approaches, some complete jokes and some very effective.
Thanks for the nice explanation. The funny parts of the video might be more educational than you think. Also, the saddle bag thing is actually not that surprising. Behind the rider is a large region of low pressure that creates a force pointing backwards. Just like the force induced by the high pressure on the frontal area. That is, if one puts material or void space in regions of low pressure the drag decreases. In addition, friction forces in fluid dynamics are proportional to the gradient of the velocity, i.e., the rate of change. Thus, if the flow follows a line as straight as possible, the drag is minimized. Even though, fluid flows around a bike and the rider is rather complicated, humans have a natural feeling about what shape creates less aerodynamic drag.
Aero if not use for racing it helps to use less energy on a long trip like 120km, also look at the positive side of the door, if you get a good tailwind it helps you get there easier.
Added the water bottle, got up to 50, maintained it for 30 seconds, tried to push on, knackered myself and had to drop out the 70.3 wasting all that money. I could have completed the race at a slower pace but I'm too cool for that. Got to respect myself
Hi guys, good video. In terms of bikes I wonder if devices that turn the air flow are better than shields. This is a common theme in motor sport, with front wings, which rather than generate lots of downforce generally turn the air around, under and over the car for better use down stream or for smooth rejoining behind (in conjunction with a cone device behind the rider as you discussed)
First, I make fairings for the big chainrings from 0.75mm thick polystyrene (0.5mm tends to get cracks) for my TT bikes, so in a side view the crank (formerly Campy Record Carbon square taper, now a FC-7410) looks like a full aero crank. It makes me faster - at least in my mind🤗. #ASKGCNTECH: As I use Giant CFR frames as a base for my TT bikes (I have two of them), I wonder whether spike tape (which is used for glider planes) sticked on the sides of the round down- and seat-tube could help that the air keeps being attached a bit more to the frame?
A narrower windscreen and one that narrows further as it comes down to cover the front of the top half of the front wheel. Like a wide diagonal and convex lance. Well, sort of.😅 When I wrote "narrower" what I should have written was the angle of the convex should sweep back more so that it is not so flat against the wind. All the best. P.S. if it is put further forward the top could angle back more I think, in which case the windscreen could even be taller and still give less wind resistance. 😊
5:00 That's a surprisingly small penalty for having bolted something with the frontal area of a tabloid newspaper to your bike. To me that says that yes, you are paying a penalty for that frontal area but that this is largely compensated for by cleaner airflow. As Ollie seems to suggest, if you actually tried a few different shapes in a wind tunnel you could probably see some real gains. Whether these are offset by handling issues remains to be seen...
There were half football handlebar fairings, very expensive and not stable mounted. Have you tried EZdisc products, a rear wheel disc cover, a crank cover and helmet cover?
You definitely need to 3d print a hard shell aero sandel bag, then when GCN has done all the aero research and development you can publish the computer file.
@@charliewhiskey8440 assuming you have an unmodified ebike, if you hit 25km/h then you're riding an unassisted bike. At that point, any assistance you can give yourself to reduce drag makes you faster.
Fluid dynamics, whether air or water, function similarly while the main difference is density. Cutting through air density is similar to the bow of a boat cutting through water density. What shape allows entrance into that medium, and exit from that medium with the least amount of turbulence and disruption and sharp directional changes of the medium? That's the key. Back in the day of early "dust bin fairings" put on racing motorcycles, eventually the regulatory bodies stepped in and started "banning" features which has ultimately led to the motorcycle fairings that are seen on sports bikes today. We've gotten used to seeing them as they are, but they are NOT the most efficient design. The original designs reached out in front of the front wheel and extended beyond the tail of the motorcycle like a fish tail. There's been independent design competitions annually in the USA where motorcyclists are encouraged to design their own home made fairings to compete with fuel consumption competitions, to see who can cover a distance in real world conditions at real world speeds but consume the least amount of fuel.
From my experience with a velomobile having an open back wheel i am very sceptical on the use of a front fairing alone (my velomobile is aerodynamically hardly better than any upright bike). It is actually the back which makes a bike fast. And the front area. So if You are interested in fairing You should look for a modern fully faired and yet relatively light weight velomobile.
@@johnyang1420 I drive an old GoOne 3 and a Leiba (Cargo). Both do not have any fairing on the tail, and the GoOne is known to need about the same power in average as an uprigt bike. There is even a comparative measurement available.
Please review GMC Denali Hydro formed aluminum Aero Frame with Aluminum aero rims, low end bike around $210 in USA. Compare to regular frame road bike on a run for aero comparison time loop. Great starter bike. Medium frame is with kickstand removed is 30 pounds
That "fairing" increases your frontal area with a worsened profile. To get benefit it would have to have a narrow frontal area and guide the air around your body
The needle between Dr Oli and Pedro has reached a new level: 2:09 before they're in the same shot together, 24.62% of the way through the video! Confirming rumours that they're contractually restricted to sharing the video for no more than 76% of screen time.
6:51 IT WAS A GENIUS JOKE I'VE EVER HEARD ENTIRE MY LIFE. I was dying because of too much laughing. Thanks for video! It was truly objective and educative video.
I wonder what the bikes would have looked like without any rules from the UCI? Let's say the only rules would be no electricity and strength tests so the bike doesn't break. Otherwise completely free. Had there perhaps been other gear systems and had we still used chains? Mix of recumbents and upright cycles?
i noticed during the TdF interviews that the racer jerseys do not have seams at the ends of the short sleeves. i assume that's an aero thing; wondering at what level of performance does something like that actually make a difference?
Saddle bag aero - yes, having worked in an automotive wind tunnel, the big gains are to be had at the back of the vehicle. So this isn't much of a surprise.
Actually, the 'wasp tail' idea is very sound. It was used to achieve speed records on motorbikes..well almost a hundred years ago. try googling Ernst Jakob Henne and you'll find some pictures with the man wearing a cone on his behind and a helmet that looks like the star wars aero helmets you see on TT races nowadays. I'd love to see that 1920's kit on a gcn presenter for a video! All in the name of saving watts!!!
A^ content here, Ollie and Alex, thanks and I've always thought there is a lot of room for fairings to help us, even minimal fairings for a deflection here and there. And what about those top-of-wheel fender fairings from years ago, they were said to help a bit. And I've always wondered if some sort of deflectors on the fork blades or on a fender or stays would make for cleaner air for all those pedal revolutions. And as far as tests, I actually prefer that you run the stopwatch outside, more realistic or something. 😀
Ahhhhhhh, yes... now the aero benefits of that large saddle bag makes sense! Of course this is still speculation, but it sounds reasonable... racing motorbikes do have that rear seat faring, similar to a bike saddle bag!
Wear a tent and see if it’s aero Or extend the plastic shield around the rider body Attach the plastic shield to the rear of the bike and then have someone draft behind. See if it’s the ultimate draft bike.
Have you ever tried something to make your bike more aero? Let us know in the comments! 👇
Eat more, to get a more aerodynamic rounded shape. :P
A deeper haircut is the most daring aero improvement for me. The next bigger would be shaving my legs, but that would make it a hell of a deal to my spouse.
I took of the fenders
The problem is AERO modern parts and bikes LOOK 1 million times better than an older bike ! Aero just looks so smart these days !
I’ve rode several handlebar fairings built 30-35 years ago: Zzipper, Breeze-Eze and AeroEdge w upper body sock for 1990 RAAM team. These had more rounded shape that the wind screen you used. I did coast-down tests in high school for physics class. The ONLY benefit I noticed was when the body sock was added. I remember my max velocity in coasting off a hill with an aero bar and no fairing was equal with the front fairing (both 21.5 mph). With the body sock it increased to 23.0 mph. In repeated one-hour runs on a rolling hill 6-mile nonstop park loop for One Hour, I noticed about a similar 1 to 1.5 mph increase from say 23.5 to 25 mph when using windscreen+ bodysock. This was 15 years ago. My name online for a longtime on recumbent forums has been Upright Mike as I was one of the few uprights competing with recumbents at human powered vehicle races. In later years, a photo of me had made it around the world several times over, being picked up website BikeSnob. I’ve been called biker in a condom, etc and got famous for adding detergent bottle /ArmorAll aero leg fairings as well.
As a former motorcycle rider I would advise you attach the wind screen to your frame rather than the handle bars to avoid "wind powered" steering
I laughed harder than I should have visualizing that, well done
but wouldn't that be very awkward in tighter turns?
@@MattRose30000 Yes. I wouldn't advise it for a mountain bike.
lol
Get a recumbent! Years ago I had four diamond frame road bikes, great ones too. Bought a recumbent and there's been no looking back. Now the happy owner of three recumbents, and a single upright. Forget about the rules backwards rules set by UCI etc. Set yourself free. And go fast!
They are not ideal for climbing, that's true. But the improved aerodynamics while on level ground, or even better when descending makes up for that 🙂 @@andreyrevyakin7272
We know that fully faired recumbent velomobiles are stunningly fast relative to a normal bike. So the question is how much of that approach can you apply to an upright bike without making it unrideable from a practical point of view. Intuitively, it seems we should be able to make significant speed gains with the right designs.
I think that a narrow windshield can give a better result. Maybe can be also useful for winter training or commuting with temps below zero.
1 2 2 4 5 6 7 8 9 and 10
The windshield looks really ugly. But I have to admit: If it helps in winter time, I might give it a try
That 's what I thought when I saw it
Good point!
Also make sure the windshield is directing the wind away from your head and more towards the top of you helmet.
The screen was essentially a wall into the air, similar to a caravan hitting the wind.
You need the screen to be curved, and probably have a shallower angle.
But if we're going for all out aero, then go with a fared recumbent!
how about the lighting f40. a faired normal bike. it looks stupid but its v fast
It's way too wide and the angle has to be far more shallow. The air has to pushed more smoothly out to the body of the rider.
Yep, I agree, I've used it many ago and it is much more aero at speeeds @30km/h than WTF GCN you showed here whis my video: ua-cam.com/video/V4VSSuG2yFY/v-deo.html
it clearly needs a conical style shape, not a police moto windshield and water shield.
They used to exist like a bubble
Zipper fairings used to be a thing. I had one during the early 80's. Would like to have one again for winter riding.
On a trip back then I did see one in Utah or thereabout. It was a lowrider as well.
Thats more like a door than an aero fairing!
An open door to aero possibilities? 😉
Somehow, every time one of these pops on the market, it invariably looks as though someone paid the designer to create something as goofy and decidedly-not-aero as possible.
MotoGP and gravity hpv fairings look nothing like this baby-riotshield, and probably for a reason 😂
A barn door one might say
Exactly, many people seem totally unaware that with aerodynamics, the way the air flows back together after is just as important as how you separate it in front.
@@gcntech eyyyyy 👉🏻👉🏻
Please test those aero fenders that attaches to the upper surface of the wheels. Those actually make alot of sense.
Good idea guys. In motorbike racing the screens are a lot more curved. As you said, front fairings on recumbents are effective.
I recall seeing, in cycling+ magazine back in the 1990s, a photo from the 1920s of a bike with a "torpele" faining (basically a tepered rear fairing made of balsa and tissue supported on legs like a carrier) that lead to a UCI ban because it made ordinary riders too fast!
That's some interesting history!
Been waiting to hear about balsa wood on bikes
@@2552legoboy Next we'll see Si 3d printing the test fairings.
I like the way this is going. Yes please do some more fairings and aero bags. I added an aero tail box to my recumbent and it made a huge difference.
Velomobile. I had. Very fast.
I swear that there's a ton of potential in bike aero, an upright rider have as much drag as an entire car. I don't think going full 'recumbent velomobile' is the solution though, but there should be a middle ground.
The reason why the saddle bag is helping (as well as the superbike designs and, indeed, the evolutionary advantage of wasps) is because when moving forward it's not only the air that you push holding you back, but as you move through the air you create a vacuum behind you. Having a smaller surface area at the end means there's a smaller surface area to get sucked back.
Yeah not a vacuum but a region of turbulence and slightly lower pressure. The rear fairing reduces the abrupt change in cross section which delays the detachment of the flow, decreasing the size of the turbulent region. The surface area actually ends up larger but skin drag contributes less than pressure drag in front-on air flow. The reason we don't go nuts with this in non-UCI bikes is because of crosswinds as they mention.
With a massive tailwind that fairing would help tremendously 😂⛵️
Not a new idea, Zzipper fairings have been around for decades. Myself and a friend rode across the US with Zzipper fairings in 1983, and when we were in central California an old farmer saw them and in a country drawl said: 'Now I've seen everything, windscreens on bi-cy-cles'...
2:22 I'd love to see you guys do a video on Chung testing of aero differences. Cheaper than a wind tunnel, and more sciencey than just a stop watch around a track.
You have to recognize the aero windscreen isn’t as much of a penalty as it looks. The idea is interesting to say the least. A lot of testing and a few interesting models and configurations could end up in an interesting game changer
I covered the sides of my frame triangles with cling film qnd gained another 10kph on my regular ride circuit, awesome 👍.
The wind guard (door) fairings are installed on motorcycle handlebars for comfort against strong winds. It’s not aero because you are blocking air with a plank on headwinds. But it’s comfortable for a motorcycle rider to not have strong winds blow into their face.
For cyclist air blowing to your face provides cooling to your head while wearing a helmet. You’ll only feel strong wind resistance on headwinds.
I used to have a Zipper fairing, 30+ years ago, that was rounded and mounted to the hoods on a road bike. Wonder how that would do?
I did too and it was both warmer
and faster in winter riding!
Use a wind tunnel with smoke, and put more angle for the screen and make it more round.
A self-inflatable rear fairing of a paragliding harness. These fairings are very light, aerodynamically optimized and don't require any rigid frame. It is probably possible to mount one on a backpack (perhaps upside down because the body position is different). The most advanced rear fairings are installed on competition harnesses such as Woody Valley X-Rated 6, Niviuk Drifter (old models), Ozone Submarine, WV X-Rated 7 (new ones). Old competition harnesses have only one parachute compartment and are banned by FAI. It should be possible to find one for a nominal price.
Olly, great point about wind effect i.e. Apparent wind and wind angle (AWA) vs True wind, becuase the effect will almost always be negative.
But a decent fairing on the front of the bike, and re-run please. I suspect 10% (!) and more at 0 deg AWA as thats the difference on my motorbike, any yaw won't help. My hypothesis ,Its about foils directing, not big shapes displacing.
I think a more forward mounted and oval windshield, very curved (not that plain plank of plastic used here), taller and with deflector shape at the borders could work really well. The problem will always be the crosswinds will throw out riders all the time.
I did, handlebar to shoulder, windscreen from foam, twenty years ago. No speed benefit, but warmer and good in rain. No any handling problem.
I do see one advantage to the "windscreen" - commuting in the rain. I road motorcycles for over 40 yrs in all sorts of weather and a windscreen helps keep the rain from beating you to death.
I would love to see you guys try some fairings ! I had that idea in the back of my head for quite some time, even thought about using some CFD software at work to try it but never really had the time 😂
Don't worry we've got plenty of time 😉
2:09 Oli's haircut looks like straight out of the wind tunnel. Aero gainz!
Anything for the gainz
In 2012 I designed my totally custom Rohloff14 tour bike. The main feature is a shark nose CF trunk attached to the head tube, about 9L volume I guess. It also has 2 bottle mounts on the back of it to the side of the head tube. It's awesomely useful, but at best I think neutral aero. But IMO it does help to have part of the wind going around that instead of hitting me. I also made a CF pouch above the BB area. And I put a thermos with a CF lid to hold tools under the BB. It points forward and acts like a ballast tank. LOL. Works great. Also have a frame bag full time. Crosswind seems to have NO effect. The thing is 78 lbs without the tour stuff. LOL I do centuries with it LOTS.
The Trans-America race rules guys sure go to EXTREME measures to expel aero. LOL. Can't even put a water bottle in front of the HT.
I have an old Mongoose DXRal bike that weighs 38.5 lbs. I ride a 5 mile road around a perimeter of a small airport near my house. In that ride, there is a stretch of half a mile that I push my MTB to the max speed. I get 15 MPH. I covered the inside frame of the bike with Glad sticky food wrap. Ran the same speed test and now I get 19 MPH. I believe it is possible to increase performance to remarkable margins with aero fairings.
It's been tested in the recumbent world that a rear fairing is realy helping more than a front fairing. It prevents the Kármán vortex street from forming and brings the air together nicely. It can actually be prevented by just a fin. This might also be why rear Disc-Wheels are so effective. Maybe you should try just building a fin behind the rider.
solid disc front wheels would be better, but steering and control in wind would go out the door. Been proven. Recumbant is already more aero, so the length of the bike is adding more disruption as the wind travels down the frame and rider. Up right the rider is half as long. two different maths.. :)
@@tonycrabtree3416 The Front disk would of course also be beneficial and I understand that it is problematic for bike control. I doubt hoever that it is more beneficial than a rear disc. Regarding the different math: Yes the Reynolds number, as well as Drag coefficient and frontal Area change and with it the amount of drag the parts create relatively. But the general effects stay the same and the Karman-vortex-street is a big producer of drag that should be avoided. Do you have any sources that show otherwise?
@@johsklopp3894It simply is. No worries, you don't have to agree.
Regarding the sum of ground speed and headwind: while the aerodynamic force may be the same, the power lost to air resistance is not. The reason is that the drag force (in N, kgf, lbf, whatever) must be multiplied by the actual ground speed to arrive at the power in watts. Therefore, a ground speed of 30km/h and a head wind of 15 km/h generate the same force as 45 km/h but does not require as much power.
Thats more like an adventure bikes windshield such as an Africa Twin or BMW GS, maybe should try a Superbike windshield such V4 Panigale or R1. 😁
That ladybug climbing on Ollie in the intro is like :D
I would love to see proper fairings tested. I can imagine the being much faster than without
Try a splitter plate. Disk wheel covers and a flat sheet of Coroplast behind your body should make a large difference.
@gcntech what about chest fairings? Heard that a bottle tucked in your jersey in the front at chest area can give an aero advantage of up to 4-5%. Pls test this.
aircraft change their shape to adapt to flight. flaps are deployed for lift when landing/taking off, spoilers for more drag to slow down, and landing gear are raised to reduce drag. basically, aircraft can change shape, but bicycles can't. bicycles have gearing which can easily be changed to adapt to different cycling conditions like hills and wind. yet, it seems the aerodynamic solutions for bicyclists are rather limited, clumsy, rigid, and impractical. it might be useful if bicyclists could deploy aerodynamics that were as easy as changing gears. since, wind is often mentioned as a detriment to cycling it might be advantageous if cyclists could have an aerodynamic feature like we do with gears... or maybe, the wind isn't as much of a detriment as we are led to believe?
You needed a propeller hat to really utilize the barn door
In unfaired recumbent bikes the seat tilt is adjustable and you lean it back farther as you get more used to the riding position.
Hold on. Apparent wind isn't as simple as adding road speed to wind speed. We all experience how much harder it is to push into wind to maintain the same road speed. Your road speed has to drop if your power input doesn't increase to make up for the increased wind drag.
I wonder if attaching some sharp trailing edges for flow separation to your outfit could help reduce drag. I’m thinking of wedge-profile foam strips glued to the back of your upper arms and your calves. Also, increasing the size of the saddle bag at the front so that it reaches over the saddle and is the same cross-section as your bum with smooth sides and sharp trailing edges, could help.
Please include a recumbent bike for reference to see all these small aero optimisations blown out of the water.
Yep! Exactly!!!
Fyi, with a power meter and a loop with some elevation change the "virtual elevation" method implemented in Golden Peak and other cycling performance software can get you wind tunnel quality measurements of CdA and rolling resistance.
Look at the 125 cc motorcycle GP racers. They’re aerodynamic. You would need to hide the legs from the wind and to a certain degree the arms as well. That lexan wind screen was close to being useless and mounted at the handlebar a disaster waiting to happen.
But if you could hid yourself from the wind, like on a motorcycle, you could pull a serious gearing and get an impressive topspeed.
Sure this wind shield will help. Or from the looks of it, just use a wooden rectangular plate and strap it to your bicycle. But always keep in mind that its surface area needs to be bigger than the rider to actually reduce air resistance.
It doesn't, it only needs to deflect air around 'messy' areas like the legs and arms to have a useful effect. But even if area is increased, remember that aerodynamic drag is Cd x area. If you can dramatically reduce Cd by smoothing the airflow then a bit of extra area may not matter.
I found a motor cycle fairing did not help with speed but small motorcycle handle bar fairings for my hands keep them warm in deepest winter.
I also lost some weight off my massive pecks which saved me 5w over a km and a lot of time in the gym
Would love to know about the detriment (or benefit) of wearing a hydration pack vs carrying 2 bottles. I always go hydration pack just because 2 bottles isn't enough hydration for me even over a modest distance, being that I'm a profuse sweater.
There was a test on GTN (I think) that showed that the hydration pack was more aero.
But
1. it needs to be in a small backpack
2. It might be very rider dependent.
So ideally you personally would have to try out different packs in the wind tunnel.
If your looking for a aero fairing. Start with something like the set up on a 125cc racing motorbike. I think I have seen a this before. The crosswind was the big problem.
I love the banter between these two
As to your air speeds, what about Crosswinds. The highway to my nearest town often has 50 mph crosswind. any rim depth at all is unrideable in those conditions. When I commuted it daily aero bikes weren't a thing yet, but rims were.
yup, Tri bike market have those front hydration systems that doubles as fairings, where you install em in front of headtube (attatched to stem)
I really would love to see aerodynamic testing with some saddle bags and backpacks!
That's a good shout!
The best way to test this would be to accelerate up to a fixed speed (maybe with a car or bike towing you) and then to coast and measure the time to slow down to a complete stop without braking. This would eliminate human error and should be done on the same bike
In '81 Zzipper fairings sold a much cleaner lighter fairing which reduced drag considerably. If look at human powered vehicle competitions have lots of different approaches, some complete jokes and some very effective.
Jan Heine made some analysys of the effects of front and rear randoneur bags. What i understood: Front bags do make a Rider more aero.
Thanks for the nice explanation. The funny parts of the video might be more educational than you think.
Also, the saddle bag thing is actually not that surprising. Behind the rider is a large region of low pressure that creates a force pointing backwards. Just like the force induced by the high pressure on the frontal area. That is, if one puts material or void space in regions of low pressure the drag decreases.
In addition, friction forces in fluid dynamics are proportional to the gradient of the velocity, i.e., the rate of change. Thus, if the flow follows a line as straight as possible, the drag is minimized. Even though, fluid flows around a bike and the rider is rather complicated, humans have a natural feeling about what shape creates less aerodynamic drag.
Aero if not use for racing it helps to use less energy on a long trip like 120km, also look at the positive side of the door, if you get a good tailwind it helps you get there easier.
I recently got a Specialized Allez. No money to aero up….a cheep aero upgrade video would be amazing!
Check out what Selle Italia did with the saddle for pro team Castorama on their TT bikes back in the early 90s
You need to try a Profike Design Aeria front hydration tank. It’s been tested to save 8w at 40km/h… that’s the same as a disc wheel
Added the water bottle, got up to 50, maintained it for 30 seconds, tried to push on, knackered myself and had to drop out the 70.3 wasting all that money. I could have completed the race at a slower pace but I'm too cool for that. Got to respect myself
Hi guys, good video. In terms of bikes I wonder if devices that turn the air flow are better than shields. This is a common theme in motor sport, with front wings, which rather than generate lots of downforce generally turn the air around, under and over the car for better use down stream or for smooth rejoining behind (in conjunction with a cone device behind the rider as you discussed)
The cone has to be in front
First, I make fairings for the big chainrings from 0.75mm thick polystyrene (0.5mm tends to get cracks) for my TT bikes, so in a side view the crank (formerly Campy Record Carbon square taper, now a FC-7410) looks like a full aero crank. It makes me faster - at least in my mind🤗.
#ASKGCNTECH: As I use Giant CFR frames as a base for my TT bikes (I have two of them), I wonder whether spike tape (which is used for glider planes) sticked on the sides of the round down- and seat-tube could help that the air keeps being attached a bit more to the frame?
A narrower windscreen and one that narrows further as it comes down to cover the front of the top half of the front wheel. Like a wide diagonal and convex lance. Well, sort of.😅 When I wrote "narrower" what I should have written was the angle of the convex should sweep back more so that it is not so flat against the wind. All the best. P.S. if it is put further forward the top could angle back more I think, in which case the windscreen could even be taller and still give less wind resistance. 😊
5:00 That's a surprisingly small penalty for having bolted something with the frontal area of a tabloid newspaper to your bike. To me that says that yes, you are paying a penalty for that frontal area but that this is largely compensated for by cleaner airflow. As Ollie seems to suggest, if you actually tried a few different shapes in a wind tunnel you could probably see some real gains. Whether these are offset by handling issues remains to be seen...
There were half football handlebar fairings, very expensive and not stable mounted.
Have you tried EZdisc products, a rear wheel disc cover, a crank cover and helmet cover?
What was the wind doing during those runs? You'd need to measure along the whole course, not just at one spot.
Try the Zipper fairing on a AM 14 Moulton, I was most impressed many years ago
0:37 Ladybugs clearly have jurisdiction though...
You definitely need to 3d print a hard shell aero sandel bag, then when GCN has done all the aero research and development you can publish the computer file.
That's an interesting one! Have you seen our documentary on 3D printed bikes on GCN+? 👉 gcn.eu/3Dprinted
This kind of test would be most valid with an electric bike 👌😎
I've always pondered whether I should put aerobars on my e-commuter
@@charliewhiskey8440 assuming you have an unmodified ebike, if you hit 25km/h then you're riding an unassisted bike.
At that point, any assistance you can give yourself to reduce drag makes you faster.
@@charliewhiskey8440 Interesting! We would love to see this in the bike vault! 👉 gcn.eu/app
Fluid dynamics, whether air or water, function similarly while the main difference is density. Cutting through air density is similar to the bow of a boat cutting through water density. What shape allows entrance into that medium, and exit from that medium with the least amount of turbulence and disruption and sharp directional changes of the medium? That's the key.
Back in the day of early "dust bin fairings" put on racing motorcycles, eventually the regulatory bodies stepped in and started "banning" features which has ultimately led to the motorcycle fairings that are seen on sports bikes today. We've gotten used to seeing them as they are, but they are NOT the most efficient design. The original designs reached out in front of the front wheel and extended beyond the tail of the motorcycle like a fish tail.
There's been independent design competitions annually in the USA where motorcyclists are encouraged to design their own home made fairings to compete with fuel consumption competitions, to see who can cover a distance in real world conditions at real world speeds but consume the least amount of fuel.
From my experience with a velomobile having an open back wheel i am very sceptical on the use of a front fairing alone (my velomobile is aerodynamically hardly better than any upright bike). It is actually the back which makes a bike fast. And the front area. So if You are interested in fairing You should look for a modern fully faired and yet relatively light weight velomobile.
Which velomobile do you have? I have a Carbon Quest
@@johnyang1420 I drive an old GoOne 3 and a Leiba (Cargo). Both do not have any fairing on the tail, and the GoOne is known to need about the same power in average as an uprigt bike. There is even a comparative measurement available.
Zzipper has been doing this since the 1980’s or so.
Notch out the recessed bottom of the wind shield and mount it as low as possible on a small wheel bike. With a forward raked angle
How about attaching a windscreen that is coneshape or pointed, like a velomobile or sportbike frontal area to make it more aero?
Please review GMC Denali Hydro formed aluminum Aero Frame with Aluminum aero rims, low end bike around $210 in USA. Compare to regular frame road bike on a run for aero comparison time loop. Great starter bike. Medium frame is with kickstand removed is 30 pounds
That "fairing" increases your frontal area with a worsened profile. To get benefit it would have to have a narrow frontal area and guide the air around your body
As one of my bikes sports a front rack and bag, I'd love to see more aero fairing testing! Even a salad bowl would improve it's aerodynamics!
why not something on the forks to move air round the legs?
The extension of the back of the bike is also a classic in cars - the long or speed tail.
If you can crack the big saddle bag as aero tail situation, there might even be a market for it with the ultra endurance bike packing crowd...
The needle between Dr Oli and Pedro has reached a new level: 2:09 before they're in the same shot together, 24.62% of the way through the video! Confirming rumours that they're contractually restricted to sharing the video for no more than 76% of screen time.
6:51 IT WAS A GENIUS JOKE I'VE EVER HEARD ENTIRE MY LIFE. I was dying because of too much laughing. Thanks for video! It was truly objective and educative video.
I'd love to see you test for the most aero ways to create a faring with a laptop bag on a bike.
I wonder what the bikes would have looked like without any rules from the UCI? Let's say the only rules would be no electricity and strength tests so the bike doesn't break. Otherwise completely free. Had there perhaps been other gear systems and had we still used chains? Mix of recumbents and upright cycles?
i noticed during the TdF interviews that the racer jerseys do not have seams at the ends of the short sleeves. i assume that's an aero thing; wondering at what level of performance does something like that actually make a difference?
tail fin? it might just work considering cars are designed as such with sloping rear end to improve aerodynamics returning better MPG.
That windscreen looks more like a shield, could a similar idea actually make an improvement if it was designed more like a superbike motorbike
road speed vs wind speed; have you ever tested this with an anemometer to see what variations you get?
Saddle bag aero - yes, having worked in an automotive wind tunnel, the big gains are to be had at the back of the vehicle. So this isn't much of a surprise.
Actually, the 'wasp tail' idea is very sound. It was used to achieve speed records on motorbikes..well almost a hundred years ago. try googling Ernst Jakob Henne and you'll find some pictures with the man wearing a cone on his behind and a helmet that looks like the star wars aero helmets you see on TT races nowadays. I'd love to see that 1920's kit on a gcn presenter for a video! All in the name of saving watts!!!
I'd like see the fUCI specialized made years ago tested. With a proper fairing
In Ireland is a needed device! Full fairings to avoid the rain and the wind! maybe some leds to simulate the sun also is good... 😂
A^ content here, Ollie and Alex, thanks and I've always thought there is a lot of room for fairings to help us, even minimal fairings for a deflection here and there. And what about those top-of-wheel fender fairings from years ago, they were said to help a bit. And I've always wondered if some sort of deflectors on the fork blades or on a fender or stays would make for cleaner air for all those pedal revolutions. And as far as tests, I actually prefer that you run the stopwatch outside, more realistic or something. 😀
As a teardrop is the ideal shape, would we be faster cycling in reverse?
Love this - made me laugh - Thanks guys made a bad day 😊 love your channel!
Ahhhhhhh, yes... now the aero benefits of that large saddle bag makes sense! Of course this is still speculation, but it sounds reasonable... racing motorbikes do have that rear seat faring, similar to a bike saddle bag!
Wear a tent and see if it’s aero
Or extend the plastic shield around the rider body
Attach the plastic shield to the rear of the bike and then have someone draft behind. See if it’s the ultimate draft bike.