Wind Tunnel Wise: How Your Bars Slow You Down!
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- เผยแพร่เมื่อ 14 พ.ค. 2024
- Learn how your handlebars can impact your aerodynamic drag for your riding or racing. Josh shares insights from a recent visit to the wind tunnel.
▬▬▬▬ Video Overview ▬▬▬▬
Josh in the first video utilizing footage from a recent wind tunnel visit, shows his Cycles Gitane Profil Aero 1981 bicycle of Tour de France fame with Bernard Hinault, and the aerodynamic features it had that were way ahead of its time. Learn how handlebar width impacts aero drag from back in 1981 up to today with modern gravel and road bicycles. SILCA athletes Ben Delaney of The Ride, Dylan Johnson and Drew Dillman came to the tunnel in search of more wattage savings. Local track star, Matt Gittings helped the conversation with some special track specific mass start handlebars. Lots of insights that many can learn from when trying to get marginal gains from which handlebars to run.
▬▬▬▬ Links & Resources ▬▬▬▬
Ben Delaney @ The Ride on TH-cam / @theridewithbendelaney
Dylan Johnson Cycling on TH-cam: / @dylanjohnsoncycling
Drew Dillman on TH-cam: / drewdillmanchannel
Wind Tunnel - Auto Research Center: www.arcindy.com/wind-tunnel.html
👀 Items featured in the video
Josh has on the TdF inspired yellow BMW 2002 t-shirt: silca.cc/collections/shirts
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LinkedIn: / silca-velo
▬▬▬▬ ABOUT SILCA ▬▬▬▬
Founded in Milan in 1917 and now based in Indianapolis, SILCA is renowned for its passion for cycling. Led by cycling industry leader, Josh Poertner, the brand has expanded from the iconic SuperPista pump to a full range of high-end cycling tools and gear, collaborating with UCI World Tour teams to enhance cycling performance. SILCA combines tradition with innovation, inspiring cyclists to enjoy both riding and maintenance.
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Do you have any questions, tips, or ideas about wind tunnel testing and aerodynamics? Let us know in the comments section below!
▬▬▬▬ ABOUT SILCA ▬▬▬▬
Founded in Milan in 1917 and now based in Indianapolis, SILCA is renowned for its cycling passion. Led by cycling industry leader, Josh Poertner, the brand has expanded from the iconic SuperPista pump to a full range of high-end cycling tools and gear, collaborating with UCI World Tour teams to enhance cycling performance. SILCA combines tradition with innovation, inspiring cyclists to enjoy both riding and maintenance. - กีฬา
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Josh always mentions his racing days, but only ever briefly. Would love to see an episode where he shares his cycling journey with us.
Ben is always great to have. Glad to see the partnership!
unfortunately many bikes (especially the larger sizes) still come with 440mm handlebars. i already switched to 400mm. takes a few miles to get used to, but it feels faster, and all data i have seen confirms that
as an Mechanical engineering student (and nerd) I love these scientific videos
how do you know someone is an engineer? They'll tell you.
@@griffithd05 you must be fun at partys
I was starting out in cycling as Dura Ace AX was failing in the market. It was tradition that you heard for some of the rational. That group didn't integrate all that well onto bikes built for Campy also.
I wondered over the years why marginal gains were abandoned. At some point in the 2000s I think a message of how Euro tradition blurred into a scoffing additude of the only gains worth chasing were to be found in PEDs.
I also watched bars get wider and thought it crazy. There was a traditional method of width lining up with shoulder joints. I began on 42cm which were the widest available. Buying bikes in recent decades meant I tried going wider but always defaulted back to 42s. It's been wild seeing big guys go so narrow as 38s.
Recently Dan of GCN put a prediction out, saying he thought riders might start using a higher position. My guess would be to get forearms horizontal ala the old Belgium position. Slammed stems have given away some aero advantage by putting more arm length blocking air.
Same goes for cranks. Why do so many bikes come with too big parts? Are there so many bodybuilders coming into cycling?
@chrisridesbicycles possibly lol. I came from competitive bodybuilding to cycling. Very wide shoulder frame.
Very nicely presented and totally convincing evidence-based analysis. Thanks. 👍
My first race bike in 1981 was a Gitane. It had a super nice Campy record groupset!. Unfortunately, it was not the aero frameset with the narrow bar, but it did have the classic Gitane honeycomb rear dropouts. Looking forward to your review of the aero model.
For as long as we rode 42/21's for a low gear, 42 bars and 175's made climbing out of the saddle much more powerful. And as long as everyone rode the same available equipment the competition was level; training was focused on the techniques that could get the best results with what we had. Everything had to change, not just the aero.
This is a great point that is rarely mentioned.. you are 100% correct that wider bars were much more about staying on top of monster climbing gears when out of the saddle than they were about breathing or seated handling.
Thanks for doing this!
Great work Josh.
Excellent discussion
What a star cast! Yes to all of them!
FINALLY IVE BEEN WAITING FOR THIS FOREVER
keen on seeing the aero performance of those old bikes compared to modern ones - both from bike only and the position it puts the rider in for a system approach.
Thank you!
More. Awesome
After a quick check, there are more 38c handlebars in my parts bin than currently for sale on eBay. All I need are shims so they will fit modern stems though.
Great stuff! I would have loved to get a bikefitters perspective on narrow(er) bars. Whether one has to expect physiological issues from going (too) narrow). I would like to be sure that the 15 W gained do not come with the expense of suffering from neck pain after one hour of my ride (which then costs me a lot of Watts for not riding optimally any more). And don't say Bernard Hinault did well with narrow ... he was a Titan (I am working to get less chrome-molly).
Comfort is speed especially past 50 miles
Love the video and data gathered from this testing and video content! The next wind tunnel test should test crank arm length and how these changes can effect power and aerodynamics.
My Dad and his mates were putting their front brakes behind fork crown in the early 70s, although i realise you're meaning production bikes.
Back in the day I had a pair of clip on drop bars that mounted similar to a clip on aero bar. Aero bars were not approved for mass start events but the clip on drops were. Haven’t seen any, even hanging in the garage for years. Wonder if that concept will come back
I was looking at the Coefficient RR bar, but was out of my price range. I found the Ritchey WCS alloy bar and they have a slight back bend which makes the elbows turn in.
I love the Coefficient bars!
Question: Is taking frontal pictures of yourself on the bike and calculating the area from the outline a usable method for getting a comparison between positions or does the drag coefficient change so much that this can easily offset a smaller frontal area?
Frontal area is a very good proxy for drag reduction. There are always some offsets to Cd from reducing the A, but as a rule of thumb a reduction in A of say 10% likely reduces CdA 8-12%
Спасибо,твои монологи, как бальзам на душу.😌
I was one of those guys in the early 80’s riding narrow bars and have noticed I no longer use the drop position.
I’m up to try a narrow bull bar with a longer reach to rest my forearms on and shorter brake levers now that disc brakes are the norm.
Dylan (and others) rests his forearms on the bars, sort of like tri bars but less comfortable. So wouldn't it make sense to get rid of the forward extension of the stem and make bars with a super long going-forward section (perhaps even with pads for forearms, like tri bars) so you could comfortably and safely (unlike tri bars) lean on them?
Speeco made some a few years ago, but the UCI banned them. Search for "Aero Breakaway Bar" or Van Schip to see them. Looks super comfy to me, I guess still legal in gravel...
As a tall dude, who has to use 140 or 150mm stems with short reach bars, those Breakaway bars seem quite interesting.
Edit: €1000 , guess not! 😂
That works till you go to sprint and you smack your knees on the bar, probably
I thought Redshift Sports has a nice gravelbar with built-in aero position "protrusion", named Kitchensink.
The Aero Breakaway Handlebar is not UCI legal.
Dropping to 38cm made huge dif for me especially on 100k graded fondo's - less np power. Also helped with crit racing but more with the contested sprint where gaps to navigate are narrow
Weight, Aerodynamics, Egonometry the triagle of perfect bike building.
Love the shout out to Omelet!
Thank you for a very informative video! Any idea how much you gain going from a round bar to an aero bar assuming they are already narrow enough? It would be very interesting to measure that!
I've been riding 38s for the las decade and it made a noticeable improvement. Now, we all know that round frames tubes are horrible aerodynamically but how close could an optimized wheelset bring it to an aero frame in watts? Could one extend the rule of 105 to match the rear edge of a wheel tire combo to the tube behind? IE: front wheel to downtube and seat tube to rear wheel? I would love to hear Josh answer this in the next episode.
Switched to Profile DRV/GMR 105 with 36 top,46 flare. Superb…aero but control when needed. This should be more the industry standard.
I've had professional bike fits and have always had to go back to my wider bars. My power drops and it is vastly more uncomfortable to run 36-42cm bars vs my 46s with some decently extended use for each size on the same model (Cowbell). At 6'3" and 200# on a 60cm, I am already not super aero, so in the scheme of things it is what it is...
You must be missing something like adjusting for reach - or the specific bars you’re using don’t work in say a 40cm.
In a similar size to you, the idea of using 46cm bars is horrifying.
Seems like the biggest headline is the importance of body position, particularly how much your arms flare out! Amazing that even with super narrow bars, poor elbow positioning basically eliminated any aero advantage.
@silca which has bigger savings? Aero frame or going from a, say, 40cm round handlebar to 40cm aero handlebar? My personal testing in the real world with testing speeds of 25-26mph indicates an aero frame is approx 7-11 watts on average over my Colnago C40, and aero handlebar with same width approx 5-7 watts. Illicting a speed increase for frame alone at .2-.3mph increase and aero handlebar approx .1-.15 mph.
I’ve been trying 32s for a while now and rode my gravel bike the other day that has 38s and it felt ridiculously wide! 😆
Dang, which 32s?
Yeah i run 38 on my gravel bike also. No issues
Can trip strips be used on high thickness to chord bar tops?
Completely contrary to this video, but please sell extra long bar tape! I just barely had enough to wrap my 44cm venturemax bars, and I really could have used about 10-20cm more tape.
Would be interesting to also hear the bike fitting/biomechanics perspective.
Please include the internationally recognized unit known as the “Portner”, which we all know is the watts saved by going to oversized pulley wheels. If I remember correctly, cheap aero socks saved 4x as much power as a set of oversized pulley wheels, or 4 Portners….😅
It would be interesting to get a bike fitters oppinion as well imo
It might be faster, but impossible to keep up
What about the Lauf fork test?
Lack of bartape on Dylan's setup probably contributed to higher drag as well. After watching Dowsett's videos it seems wind likes to be disrupted as we move through it or vice versa.
I love how you dunked on Fahrenheit in a recent video but I’m sad to see you use miles per hour predominantly in this one. Use metric! Kilometers is superior to miles. Thanks for using centimeters for bar width 😊
For a quick, very approximate mental shortcut for miles to kilometres I use the Fibbonaci sequence. …2,3,5,8,13.. so 21mi->34kph etc. it is a pain though. lbs to kg is mentally jarring too
Very interesting 👍.
Just a question, I see the test with static position. When pedaling, could we observe any others results ?
And not only pedalling but also steering the bike on rough terrain. Such videos are just bro science attempted to present like real science.
We test both ways, non pedaling for component and equipment changes as the noise in the data is significantly reduced, and then pedaling for rider position work as the rider has to be comfortable and be able to maintain the position over a period of time and we look to see that the data doesn't drift from the rider moving out of position. In general, the rider with legs at 3/9 o'clock like this gives very nearly the same drag as if the rider is pedaling but with 10x reduction in noise.
Good stuff! Here is an XC MTB question for future consideration. I just got my first Fox Stepcast fork, which is considerably more narrow than other forks on the market. What, if any aero gains could be expected from it? Especially considering where the fork is on the bike and that it doesn’t impact rider position at all, and with the riders legs behind it maybe there is no benefit at all?
There is almost zero frontal area reduction to a narrower suspension fork so no real gain there, but likely no penalty either. You'd have to make it wider to get the fork legs more inline with the riders legs to really see any improvement. However, even the tiniest ovalization of the fork legs could make a huge difference to aero, same with the crown, it would take just some slight shaping to make it notably faster. The Lauf Grit is a good example of how just a little shaping of the thing can dramatically improve aero, making it more aero than most rigid gravel forks we've seen despite having all of the extra pieces and parts hanging off the back.
@@SILCAVelo thanks, good info!
Very cool to hear about the Lauf. Love mine, and have noticed the profiling on it and wondered.
Well I have 52cm bars, how many watts would it save if I went to 40 - 42mm bars at 40/km/hr?
How about the supposed benefit of wider bars for improved control on unpaved surfaces?
The general consensus amongst athletes we work with is that after a week or so of riding, the narrower bars are no different in stability or control.
That’s interesting. Although I assume it wouldn’t hold for the track bars!
Curious about the frontal area difference between modern humongous headtubes vs 1940s-1990s headtubes
The Cervelo in our test shows us that if it's aero shaped it can be much faster, but if it's round..it's just more bad. We will cover this in an upcoming roundup on the bikes from that test.
Hi Josh, Dylans Cat tongue tape. the dimples or design pattern on that, does that do any tripping? cheers,
He's using it on a pretty aero shape so it's more likely a net loss than an improvement. Textures really only work on 'bluff body' shapes which have not been streamlined.
Everything you say is true….if you’re racing for a living. For the other 99.999% of riders you should choose what’s comfortable. Comfort = more riding = faster
watching coverage from the spring classics, looks like lots of guys with narrow bars are chicken winging badly.
What's the point of going narrow if you can't ride the position?
There's definitely a cargo cult thing that happens in pro racing where teams or riders copy what others are doing without fully understanding why they're doing it.. fatigue is the other factor here as it does take some effort to keep the elbows in. Having said that, the worst case scenario with chicken winging is still roughly on par with to slightly better than riding wider bars in the first place, so there's some real asymmetry here where you either get a solid benefit or at worst, no benefit at all.
Not related to this video, sorry, but seeing the increasing demand and current popularity of immersive waxing, i wonder if a company like Silca would benefit greatly from designing their own reusable quick links, because i think reusing standard ones is one of the biggest worries people have before commiting to that process. And so far only Connex sell "limitless" reusable quick links. Thanks.
How can i avoid the chicken wings? When flexing outwards my pecs are taking over more of my weight. When arms are straight my triceps gets overloaded after a few hours. Would a longer stem help?
I'm curious how these bars affect sprinters. I'm a big guy (190cm, 85kg) and that's how I win races usually. I've been experimenting with narrow bars but they all don't feel great when sprinting out of the saddle in the drops. Is there a too narrow? Are narrow bars for breakaway guys only? I love all this aero data, but it's all in a stable "solo break" position and I'm just wondering about out of the saddle efforts.
Edit: Also, does the flare affect the aero gains? Like, would a bar that's 38 tops and 38 drops be more aero than a bar that's 38 tops and 43 dops?
I think that it really just depends on the time spent adapting to the narrower bars. If you look at track sprinting and points racing right now, pretty much everybody is on a sub 34cm bar, and while it looks a little different than it used to, the speeds are higher than ever. I think that bars with flared drops are a great way to have your cake and eat it too.. 37-38 on the hoods for fast cruising and then something more traditionally wide for field sprinting.
build up your body the engine for strength and speed then the power is to come!!!
What about bar tape vs no bar tape on a flat top bar?
At what point does going too narrower become too unstable and is there a potential to screw with your position from a comfort standpoint? Interested in going to a narrower bar but don't want to sacrifice comfort. I'm 6'3" with an average build. Should I try 40 width bars?
I am 6‘8“ and recently switched to 38cm EXS Aerover integrated bars and love them.
Us tall dudes need every help we can get to cheat the wind
Depends more on shoulder width than height. I’ve heard narrower can even help to some extent if you need more stem length
Maybe breathing isn’t impacted, but how is handling impacted, particularly on fast descents, with very narrow bars? Those 26mm bars might be fine on flat roads in a TT, but I wouldn’t want them on alpine descents. Also, wider bars can be more comfortable when climbing, especially out of the saddle.
We've helped 2 world tour teams make this transition as well as number of gravel racers and at 37-38cm bar width, everybody gets used to it in a week or so. Narrower than that gets much harder, and the track guys end up needing smaller bikes with longer stems to help offset the sub 30cm bars. Having said that, the watt savings for Ben going from 46 to 42cm bar is more than 15X greater than the benefit of converting to a top of the line oversized/ceramic pulley system, so this is right up there with aero socks as being one of the most cost effective performance gains that you can just buy.
Very amateur rider here, moved to 38cm on my gravel bike based on aero efficiency but also ergonomics as my shoulders are close to similar anyways. Yep, took about a week of getting used to things and haven’t looked back.
The short answer is that it's actually improved. You don't steer a bicycle like a tractor by wrenching on the steering with leverage, you can steer it without even having your hands on the bars at all.
@@galenkehler what are you talking about, you don’t steer a bike by turning the bars. Turning is done by leaning the bike into the corners, the bars help control the extent of the lean. There is a reason TT bikes are crap at climbing and descending. Having your hands narrow and in the middle of the bars doesn’t give much leverage to control anything. By your logic TT bikes should handle the same as a road bike. Let’s see you steer into a high speed corner >70km/h withiut your hands champ.
@@Adonis-qj1nq you seem to be contradicting yourself, but also have a few things incorrect, so I'll try and go through it. The first sentence, you say you don't steer by turning the bars, which is what I said as well. But then you go on to contadict yourself, talking about "leverage", and how TT bikes are bad at climbing and descending because your hands are narrow. You need to sort that out in your reasoning.
Later you say that by my logic, TT bikes should handle the same as a road bike. Long story short, they do! I use a TT bike with drop bars for my road bike, for fit reasons so I can get a long reach with a low stack. I did this specifically for the handling improvement of having a reasonable stem length.
This might be a strange thing to say, but I think racers knew narrower was faster and that's why we had the "puppy paws" position that has been outlawed, right? To me, the narrow bars is just a UCI legal way to get back to the speed of the "puppy paws"for the pro peloton
In a sense, yes! Same with angled hoods.. narrower is just faster and the riders know it.
Aero bar or narrow bar? Is a narrow round tube bar going to save more watts compared to an aero profile bar that is a few centimeters wider? Would be great if the answer is yes so I can go buy a cheap aluminum bar instead of an expensive aero carbon bar.
Get a cheap aluminium bar and route the cables so it becomes a flattened bar :-)
Narrower bars can have downsides in terms of handling especially with deeper rims. I know of at least one gravel race that is definitely won on a rowdy descent. So as above…it depends.
Is it the bars inherently or the body position, my point 👉 being it's safer with 40cm bars are they less Cda cost, but somehow change location of brake hoods greatly to allow narrow arm position when tucked in... can we save close to as much Cda 🤷♂️
How many amateurs can safely descend on a sub 40 bar? Even the pro peloton seems to have problems with them given the increased number of crashes on descents this season
Interesting. Watss/Kg data would be useful to compare.
How does one quantify the other consequences of using narrower bars - typically more arm, back and upper body fatigue? Working harder to control the bike also wastes energy, not to mention the discomfort induced by riding a narrower than natural handlebar.
You have to remember that the 'consequences' here are mainly if not entirely just theoretical.. this doesn't work for everybody, but I'm yet to put an athlete on a 37-38cm bar and have them go back after 2 weeks of trial period and this includes WorldTour riders on whom we have immense data and can measure things like fatigue, energy use, etc.. and once the rider is adapted we just don't see any of that stuff, and in fact we just see higher speeds and/or lower energy use through the improved aero.
@@SILCAVelo I was asking the question more from the perspective of somebody who is not a professional athlete and who typically adapts very slowly (if not at all) to significant changes in posture and bike fit. But fair enough, maybe this is not for everybody.
What are these 26cm track bars called? :)
We had bars from Toot and also Mythos, though there are others making them as well.
@@SILCAVeloThanks!
Going exceptionally narrow, doesn’t this start to sacrifice your stability especially in turns. If ideally the narrowness of the bar is a function of the shoulder width ; how many centimeters more narrow should you go. Just cause you can doesn’t mean you should.
#naerobars
I’m curious about the aero undershirts like rule28 has. My jersey has a ribbed pattern in it already will the aero undershirt provide an aero benefit still? Or would the benefit be less due to the ribbed jersey?
26cm bar, you could just go all the way to a pair of clip ons.
I use wide bars on my gravel bike because not losing my bars in sand/ruts/potholes and unstable conditions is more important than aerodynamics. Also more hand position/width options.
That's why flared bars are amazing. You have your narrow aero position on the hoods and a wider, easier to control position in the drops.
Even for a real life daily road riding anything narrower than 40 cm starts getting compromised handling, and by 36 cm it becomes severely dangerous suitable only for riding a straight line on a very good condition road sections.
Odd to make such a seemingly absolute statement about 36cm bars. Surely, you're not speaking for all the people who get along just fine with narrow bars... are you?
I was also getting along well with narrow bars but don’t use them anymore after I was forced to turn on looser sand road sections. Very hard to control the bike, even with 42cm handlebars it’s challenging but at least you have a chance. With narrow bars no chance.
@@tongotongo3143 bars on my gravel bike measure 38cm on top, I also have levers turned in, so it's 34cm wide where I'm actually holding them. I've done an xc race on it just fine, deep sand isn't a problem either
Put Ben next to Dylan on the same road and have Ben ride at 190w and Dylan at 120w...you really want people to believe Dylan is going to be going any where near as fast as Ben? These tests are so silly at this point.
I believe that Ben would need 360 W to go 32 kph compared to the 300 W Dylan would have to put out. Especially in case of some headwind.
So these are only aero watts we're discussing.. but yes, they would each add say 60 rolling resistance watts and 6-8 drivetrain watts to both of their numbers to get the full totals, but absolutely, if Dylan requires 60 fewer aero watts to go the same speed, then side by side, he's going the exact same speed on 60 fewer watts.
Narrow bar is likely more aero but being narrow would also reduce the bike control outside of wind tunnel…
From experience that's not true on the bike control front. Have done madison exchanges on the track at 70kph on those 26cm bars with zero issues. I've also descended twisty mountain descents at nearly 100kph on 33cm C-C bars with no problems (it actually felt better than my old 35s). Don't knock it until you try it. Again, going that narrow isn't for everyone....However most just make assumptions.
Your videos are so interesting!
Could you please explain why the riders don't pedal in the windtunnel tests? My guess is that the aerodynamic numbers are different when the legs are moving and creating turbulence. And the aero difference with a narrower bar will relative be smaller?
1000% agree. Make the riders pedal, and do what we all do. Fidget, adjust, look up, look down, and all those things that will upset the aerodynamics. Then, tell us the results. Putting some crosswinds, cars passing, riders passing! and other real life air movement parameters into the mix will also affect the laminar and wake fluid dynamics. The testing is too sterile for me to accept the results. But, a good step in the right direction. Training and focusing on maintaining a great aerodynamic posture will get better results than re-investing on re-aligned handlebars
I think this test would not survive in academia. I love Cilca and their research presented is normally quite good, but this one is not.
Because, the test was not whether the narrow bars were faster but you just tested different rider positions. So the width of the bar is not the explanatory variabel, but is merely a moderator which resulted in different rider positions which explained drag.
Next time test different bar widths when riding in the same tt position, so both hands in the middle of the steer.
rules must intervene to stop these trends.
Initialy cycling was about enjoying roads and racing was about who is the fittest.
Now cycling is about who spend the most on his bike and racing is about who is the most stupid with his set up.
26cm bar and 0 control 😂
"Lower speeds of 32kph" Ha! Please try some tests down at 20kph. That's more like my gravel speeds, and likely a fair number of 'regular folks' too.
This has been discussed a lot before. You don’t want to test at super slow speeds, because it’s hard to get a good signal:noise ratio. But, you can calculate the savings at 20 km/hr from the data you got at 30 or 40 km/hr.
Specialized Wintunnel project did the math to show that fast and slow riders save roughly the same time/distance for any particular aero gain. Although the speed increases are smaller for slower riders, they are put there longer , so a smaller gain per minute, but multiplied by more minutes. Of course, slower people tend to ride shorter distances.
If you are interested in, Ben Delaynyes channel “The Ride” has info in one of his videos about this, where he links to several online models, where you can calculate your own estimates for adjusting different variables , including power or speed.
The widest part of your body are your Shoulders. I can't see how narrower bars would make much difference..
Generally the narrower bars put your arms in front of your body rather than out beside it.. in simplest terms it reduces your frontal area presented to the wind.
Nothing more useless than testing gear in a wind tunnel
Easily the most famous Laurent Fignon quote!