Podcast: Wind Tunnel Testing With Tahnée Seagrave

Jan 21, 2020 at 9:51
by Downtime Podcast  
Photo by Dan Hearn

Words - Chris Hall // Photography - Dan Hearn

With gaps like 0.581 of a second splitting Loic Bruni and Troy Brosnan for gold and silver medals at the 2019 World Champs in Mont-Sainte-Anne, and 0.94 of a second separating Eddie Masters and Richie Rude after 43 minutes of racing in Les Orres, it’s clear that marginal gains have a role to play in competition. These small gains can definitely impact the results, and change the makeup of the podium.

So with that in mind, where do riders look for these marginal gains? Clearly there are myriad things a rider can and does do, in order to be their best when it’s time to compete. One area that has had much speculation over the years is aerodynamics. If you’re as old as me then you’ll remember the days of skinsuits and riding without a helmet peak which certainly created some controversy. Both were effectively banned as a lot of people felt it damaged the look of the sport, but that’s not going to stop people looking for gains. Rules are always open to interpretation.

Trek World Racing put Tracy Moseley, Justin Leov and Andrew Neethling in a wind tunnel back in 2009, in 2016 Specialized Gravity carried out wind tunnel testing with Loic Bruni and Loris Vergier, and who knows what other teams might have done behind closed doors. Clearly no one is going to share their results, but it would be hard to miss the move from shorts to full pants, and a clear trend towards tighter fitting clothing, especially when race runs come around.

Are there still aerodynamic gains to be had? Well, that’s what I wanted to find out, and after a recent podcast episode with Formula 1 aerodynamics guru, Tony Salter, the door was opened on a way to do just that. It turns out that Tony’s ex-boss had been involved in setting up a sports specific wind tunnel and Tony was wondering if I knew of any teams that might be keen to come and do some testing. I didn’t need asking twice and was straight on the phone to Tony Seagrave from FMD Racing to see if he’d be keen to put Tahnée in the wind tunnel. Not surprisingly he was, so early this year, we headed to Silverstone Sports Engineering Hub to see what we could find out.

Photo by Dan Hearn
Time for coffee and test planning.
Photo by Dan Hearn
Tony explains to Tahnée what to expect.

Photo by Dan Hearn
The bike is held in place with slim supports so as not to affect the test results.

Photo by Dan Hearn
Ready to go... time for run 1.

Photo by Dan Hearn
Data is projected on the floor for Tahnée to see during test runs.
Photo by Dan Hearn
Edge detection allows the rider to ensure they repeat the same position.

Photo by Dan Hearn
Each test run was discussed in detail between Tahnée and the test team.

Photo by Dan Hearn
Even small changes can make a big difference.
Photo by Dan Hearn
The plan was modified through the day as we learned more.

Photo by Dan Hearn
The all important tuck.

Photo by Dan Hearn
Dip and get low.
Photo by Dan Hearn
Fabien is a man with a plan.

Photo by Dan Hearn
What an amazing facility.

Photo by Dan Hearn
When your team boss and Dad helps you understand what the wind tunnel might feel like.

Photo by Dan Hearn
This is where the wind actually comes from.

Photo by Dan Hearn
Wind tunnel squad.
Photo by Dan Hearn
Why not?

Photo by Dan Hearn
Just how aerodynamic is a no-hander anyway?

Photo by Dan Hearn
Gain seekers went home happy

So are there still aerodynamic gains to be had? Well let's just say we were pretty surprised at the impact of some of the changes that we made throughout the day. Eye-opening indeed!

Keep a close eye on Tahnée at the races this year and see if you can spot any aerodynamic changes from her 2019 set up.

If you want to hear more about the wind tunnel testing, along with interviews with Fabien and Tahnée, then listen to the latest episode of the podcast by using the player below.


You can also listen by searching for ‘Downtime Podcast’ on iTunes, Spotify, or Google Podcasts, by asking Alexa, or over on our website www.downtimepodcast.com/wind-tunnel/ and you can follow us on Instagram @downtimepodcast


131 Comments

  • 108 1
 I asked my wife if we could do a wind tunnel test. She said she's not that type of girl.
  • 22 0
 You've got no tuckin chance mate
  • 10 116
flag heavyp (Jan 22, 2020 at 1:59) (Below Threshold)
 Click bait! @trek did this back in 2009!, Next .......
  • 78 0
 @heavyp: sorry mate, I thought people might be interested. I did mention the Trek testing in the article, and the 2016 Specialized testing too, all steps along a path of continual progress in my eyes.
  • 35 0
 @heavyp: I think your threshold for what constitutes click bait is generally quite low mate.
  • 8 0
 @dropthedebt I want to upvote but it's currently at 69, so obviously I can't. So hereby I sent you the props via comment!
  • 5 0
 I wish I could down vote myself, sorry everyone I only looked at the pictures haha
  • 1 1
 she's like the wind.
….through my tree
She rides the night next to me
She leads me through moonlight
Only to burn me with the sun
She's taken my heart
But she doesn't know what she's done
  • 34 0
 In other news, words have been found to be more rdnmc wtht vwls.
  • 28 0
 If I was in NCIS, I would take the 5th picture, zoom in Tahnée's goggles, duplicate the pixels, zoom in the window's reflect in the goggles, duplicate the pixels, zoom in Fabien's reflect in the window's reflect in the goggles, duplicate the pixels, zoom in his right eye, find the bike's reflect, zoom in, duplicate the pixels, and finally assume that the New Sender is slacker than the old one by 0.5°
  • 1 0
 @acdownhill: That's the accurate word, thanks !
  • 6 1
 ENHANCE!
  • 2 0
 @conoat: I wonder how many folks get the Blade Runner reference?
  • 1 0
 @GeoMurph5: looks like 3. Smile
  • 16 3
 Not a lot of information came out of that podcast. Maybe would have been better using an non-competing rider as it seemed that they had funded it and any research they were keeping close to their chests. Your body position changes so much over the course of a track which has a massive drag, aero stuff to clothing must make a minimal difference. Probably best to work out where you can minimise body shape on certain parts as the best pros already do. If tracks were steep , rocky, rooty and natural like we all want it'd probably have even less of a factor.
  • 28 1
 Sorry @Chilliwacker you're right, no racer is going to want that sort of information to be shared. If I had any budget then I could have put myself in the wind tunnel and shared this sort of information with you, but unfortunately, I'm far from being in that position as I'm sure you will be aware from listening to this episode.
  • 1 0
 Can we see Fabio in the wind tunnel? I am sure there is a lot to learn from his perspective.
  • 3 3
 @downtimepodcast: The "information" is not a secret, just watch Amaury Pieron in any of his race runs. Get your head down by the bars and keep your ass up to be more aero. The hard part is keeping the bike under control while doing this wherever you can. Pieron is the master of aero, he does it so quickly and in spots on the track where other racers don't.
  • 3 0
 @ButtermilkBar: ok, bad choice of words.. the data/results are secret. I totally agree with you though, Amaury definitely seems to know what's going on!
  • 16 0
 No one else notice that that is not a current Sender?
  • 3 0
 www.pinkbike.com/photo/18196027
if you look on the floor the linkage looks different
  • 2 0
 @jonaslp1: yep, and the headtube! Very keen to see some other images of it! Having had the current one I hope they addressed the lack of progression in the linkage with the new one. Fingers crossed for a mullet version, I would definitely purchase if that was the case!
  • 6 1
 Sender 2020 First Ride tomorrow
  • 1 0
 @qreative-bicycle: Haha we shall see
  • 1 0
 @Ralston88: yes the head tube and the I think that kink/hunch in the opper side of the top tube behind the stem is new . The current Sender's top tube seems to go straight down.
  • 2 0
 Yep, Fox 49 !
And on the 5th photo, you can see the headtube area which different, plus, front wheel and back wheel aren't at the same height. Must be a 29/27 version
  • 11 1
 What about the visor on a fullface? Better something like a road moto helmet???
  • 2 1
 It's called a peak, and its required on a DH helmet.
  • 4 1
 @RonSauce: Fox calls them visor if you want to order a new one ;-) Thanks for teaching
  • 1 1
 @Chridel: UCI:
.3.012 A full-face helmet must be worn properly both when racing and when training on the course. The helmet must be fitted with a peak. Open-face helmets may not be worn.

Fox can call it a chicken sandwich if they want, but it is a peak. I very clearly and accurately answered your question, you're welcome.
  • 2 0
 @RonSauce: Strange, I'm not a native speaker but if i search for visor, I find TLD, Fox and all the others list it as spare part...peak comes up here and now, but not seems to be used outside of the UCI a lot, just from my little non-representive web research of how the company's name that thing on the helmet they produce ;-)

Lets leave it that way ;-) Not worth it mate
  • 2 0
 @Chridel: my apology, I misread the tone of your comment, and tried to delete my rude response. I'm still trying to delete it.
  • 1 0
 @RonSauce: alright, not really something to worry about ;-) Cheers
  • 9 1
 If a straights long enough straight enough and smooth enough to get the perfect tuck and actually make a difference why is it on the DH calender?
  • 18 9
 please just stop there, I don't want to watch DH racers dressed as roadies
  • 10 1
 they won't be, lycra elastane based clothing is banned by the regs
  • 5 1
 @downtimepodcast: for how long...
  • 15 0
 @f00bar: hard to say. My understanding is that it was put into the rules to stop people using skinsuits. However, for some riders the kit is nearly skinsuit tight these days anyway. That being said, I think the current race kit looks really good. I can't see skinsuits making a comeback any day soon, but riders will want to make sure that the kit they are wearing is as good as it can be without being a skinsuit for sure.
  • 16 2
 why does what they wear upset you enough that you'd rather they didn't go as fast as possible?
  • 4 18
flag f00bar (Jan 22, 2020 at 3:12) (Below Threshold)
 @mashrv1: because loose (or even baggy) clothes are part of the DH/FR legacy, along with the laid back attitude and bro culture. I would not even notice those milliseconds of difference if the racers were dressed in lycra, and if I want to watch roadies, I'll tune in to TdF.
  • 9 0
 @downtimepodcast: So now they'll just wear the smallest tightest fitting clothing there is. The trend has been going that way anyway. When it comes to hundredths of seconds, no one wants to wear a parachute.
  • 3 0
 @neimbc: yeah, that's the reality of trying to go as fast as you can against the clock I guess... can't argue with physics.
  • 4 0
 @neimbc: They also gotta fit some protection in there for those times you go OTB at 30mph into a rock garden.
  • 3 1
 @f00bar: baggy stuffs are "has been" since 98 more or less!
  • 1 0
 UCI and Redbull are down on viewers, they are looking to spice it up!
  • 2 0
 I get why the aesthetic of Lycra doesn't jive with DH racing. But I think what we all want is a high performance racing circuit, extracting every second they can from the clock. If Lycra makes insanely fast riders faster, then I say we "let them eat cake".
  • 7 0
 At 50 kph aerodynamic drag makes for about 90% of the force slowing you down. So besides the riding itself its the area with the most potential for improvement I'd think.
  • 6 0
 Easy win, peak off and no helmet mounted GoPro. That’s got to be worth two tenths of a tad.
  • 1 0
 Sooo dumb that people are adjusting their helmet go pros right before runs, or some team guy runs over to adjust it, get that shit off racers heads
  • 2 0
 @mkotowski1: We need those Pov runs lol
  • 3 0
 For those who are wondering here are the UCI rules on clothing and helmets.

UCI CYCLING REGULATIONS

PART 4 MOUNTAIN BIKE

Clothing and protective accessories

4.3.011 All lycra-elastane based tight-fitting clothing is not permitted.

4.3.012 A full-face helmet must be worn properly both when racing and when training on the
course. The helmet must be fitted with a peak. Open-face helmets may not be worn.

www.uci.org/docs/default-source/rules-and-regulations/4mtb-e-1.01.2019---final---ok-publication.pdf?sfvrsn=9954e8cc_20
  • 6 0
 Pony tail not as aero as a braid: youtu.be/Lf5jL__kws0
  • 1 0
 Watching now!
  • 2 0
 that is ace, must learn to braid my wonder locks.
  • 4 0
 No number plate? One of the biggest aerodynamic factors? The air deflected by the number plate can mean a big difference in the best tuck.
  • 2 0
 not that they're showing, could have had a proto plate holder with aero designs....
  • 3 0
 By 2020 should we expect even more bike park-like dh tracks? (Anyway the name of the team reminds me to videosurveillance CCTV )
  • 1 0
 Well when baggy cloths make 5 seconds difference according to Ben Cathro so fashion rather than function is the UCI way, Is wind tunnel tested going to be against the rules or even testing areo position really a safe way to go fast?
  • 3 0
 team goes for a wind tunnel test looking for marginal gains; it's ok the rider to have a pony tail flapping around.
That's how serious this matter is.
  • 7 6
 Are we allowed to talk properly about skinsuits again?
Cos if not, why not.
Easily the most ridiculous UCI rule ever.
DH is the only self-propelled time trial sport where they're disallowed, because "reasons" apparently
  • 15 0
 The reason skinsuits were banned, was because they gave the riders an incentive to ditch body armour in favour of even more aerodynamic advantage. I think the intention behind that rule was a good thing and meant to keep the riders save.
  • 11 0
 Worked out really well in my opinion. Clothing and gear designers were forced to advance materials & cuts that created a form and fashion design style that is bleeding over into the sports we were mimicking. Moto gear is leaning more toward DH kit now & other sports too. DH has been able to establish it's own rules of equipment. I think we need to stick with it too because in the end the rider and their run is what determines the winner in this sport if they all are using current regulations.
Turn gear rules into downhill ski rules again & we just become boring & gimmicky again.
  • 2 0
 I respectfully, but strongly disagree
  • 3 1
 @IllestT: with yourself?
  • 1 0
 @FR33DOMdotCOM: then all they have to do is make pads mandatory, not worry about what materials they are wearing. Its lycra that's not allowed, not a particular cut.
  • 4 0
 @blowmyfuse:
Totally agree.
Those lads and girls on the circuit look good in the kit they're wearing and it has evolved to be functionally adapted to the sport instead of wearing hand offs from motocross.
The guys complaining the loudest are probably mostly slightly overweight middle aged guys who cannot in good conscience wear the same stuff without looking ridiculous. It's OK, more baggy fitting stuff is available and nobody is judging, but if those who can wear it are able to gain an advantage while looking good, where's the problem with that?
Seriously, I've been around long enough to witness the change and I welcome it. Modern riding gear is the most comfortable I've ever been on a bike. No floppy cloth to catch on a saddle, no chafing sounds while pedaling and most importantly, not looking like a goofy wannabe motox rider to civilians in the parking lot. We finally have our own identity and it helps change the public perception in my experience. People stopped viewing dh as some sort of freakshow for guys with too high a sensation seeking and give it credit as a legitimate sport, in part I'm sure because now we dress like athletes. I wouldn't wanna miss the old times but clothing just has gotten a lot better and downhill has matured into doing its own thing.
  • 1 0
 @FR33DOMdotCOM: my ass. Totally aesthetic decission.
If you want protection, you enforce protecion, not ban something totally different. As if skin suits couldn't be worn over armor...
  • 8 5
 If this is needed to win by Nths of a second, there's something wrong with DH.........
  • 9 1
 I wouldn't say that it's 'needed', but you can't avoid the fact that it's going to play a role in how fast you get down the track. So as a racer, if you want to win, why wouldn't you be looking at everything that can help you go faster? It's just one of many areas that the top riders have to address.
  • 3 7
flag nojzilla (Jan 22, 2020 at 4:01) (Below Threshold)
 @downtimepodcast: Down Hill used to be about skill an courage not wind tucks like its the fkng TDF
  • 5 1
 @nojzilla: I think it would be pretty hard to say that it's no longer about skill, but as the sport progresses, riders get closer for sure, and marginal gains become more relevant than they used to be. The progress in bike technology, physical and mental preparation etc are all part of what's driving this. Clearly there is the argument that courses have changed due to the demands of television, but on the flip side, MSA has been on the circuit way before that was a concern and it has some of the highest speed sections with potentially the most to gain from a good tuck. So I think skill is still a huge requirement (the number one), but there is way more needed if you want to consistently be the best rider. For me, that makes it really exciting, and if it's the choice between watching DH racing or the TDF, I'm picking DH.
  • 3 1
 But that is the direction downhill is heading. It's gaining popularity and the field as a result is getting stacked. It's probably only the very top teams who will be looking for these tenths but then the tech gets trickled down. It's just evolution.
  • 1 0
 @dubod22: Hence, my comment above
  • 3 0
 The reality of racing to win is that every little Nth counts.
  • 4 1
 If races are being decided by nth of a second then it's going in the right direction.
  • 2 4
 @edreyes: boooooooooring
  • 2 0
 For sure dude, the scene is definitely going downhill.
  • 1 2
 Hardline world series would kill off UCI DH ......
  • 2 0
 Yeti, Troy Lee and HED pioneered that shit back in the 90's don't forget. Looking for advantages in the Kamikaze. They had some interesting fork fairings etc.
  • 1 1
 I would take the results and throw them straight into the garbage. The wheels aren't spinning, that tread spinning and the spokes cutting through the air will make a big difference. F1 has been using a rolling windtunnel for years to capture that data. I would be very interested in seeing the impact of scrubbing and other in flight aero.
  • 6 0
 the wheels don't spin in photos
  • 1 0
 @downtimepodcast: that comment can be taken in two ways.
  • 3 0
 As the manager of a top ranked DH World Cup Team (fantasy), I found this an extremely informative podcast.
  • 2 0
 love it! glad you enjoyed it @Superburner
  • 3 1
 Stop commenting and make a donation to the podcast to keep it running. I myself look forward to it weekly whilst commuting and any way we can help is a good thing ????
  • 1 0
 Thanks @wilson360 that's super kind!
  • 3 1
 Can we just wear skinsuits and remove the helmet's lid like the good ole days?
  • 5 1
 Please don´t.
  • 2 0
 Sooo wings on mountain bikes next?? They're already a thing on sportbike racing.
  • 3 2
 If your not gonna wear a skin suit (proven faster due to arrow) then its not worth wind testing the bike which will have less effect than the skin suit will.
  • 3 1
 But you can't wear a skinsuit in DH. So the bike and riding position is all you have to optimize.
  • 1 3
 @Domowoi: hahahaa youve never seen the old days of racing where everyone was in skin suits Vories, claudio, ect.
  • 1 1
 @Domowoi: You could, but the whole team would have to commit to it for the full season.
  • 2 0
 It is common knowledge that if you shave your entire body that you will be faster at DH.
  • 3 0
 Mullet Sender...
  • 1 0
 The guide for cable in the front is different. Top tube too I think
  • 3 0
 @guiv34: new Sender is coming
  • 4 1
 Propper interesting
  • 2 2
 it had potential to be interesting, instead it was just a prick tease.
  • 4 0
 @xenonchris: what would you have liked to hear? I'm always open to feedback.
  • 1 2
 @downtimepodcast: Details of the new Sender she's sat on?
  • 3 0
 @downtimepodcast: it’s not your fault, it’s just that the most interesting thing about this would be the results and of course they’re not sharing. Makes it a bit of a let down. @pinkbike you’ve got deep enough pockets, let’s see it!
  • 4 0
 @BiNARYBiKE: if someone wants to pay me to go in the windtunnel and get you some results, then I'm in!
  • 2 0
 I wonder which different it makes to ride without number plate...
  • 2 0
 I think Ben Cathro mentioned cutting down his number plate to help with aero. Would have been interesting to see what differences that could make.
  • 1 0
 @finbarrmc: the Odi number Plate are made for best dynamik, all little things helped
  • 1 0
 Stick a bar-end cap in the bottom of that steerer tube and you'll save .000014 -Job done.
  • 2 0
 this is exciting. I hope she kills it this season.
  • 9 12
 Wth gps lk 0.581 f scnd splttng Lc Brn nd Try Brsnn fr gld nd slvr mdls t th 2019 Wrld Chmps n Mnt-Snt-nn, nd 0.94 f scnd sprtng dd Mstrs nd Rch Rd ftr 43 mnts f rcng n Ls rrs, t’s clr tht mrgnl gns hv rl t ply n cmpttn. Ths smll gns cn dfntly mpct th rslts, nd chng th mkp f th pdm.

S wth tht n mnd, whr d rdrs lk fr ths mrgnl gns? Clrly thr r myrd thngs rdr cn nd ds d, n rdr t b thr bst whn t’s tm t cmpt. n r tht hs hd mch spcltn vr th yrs s rdynmcs. f y’r s ld s m thn y’ll rmmbr th dys f sknsts nd rdng wtht hlmt pk whch crtnly crtd sm cntrvrsy. Bth wr ffctvly bnnd s lt f ppl flt t dmgd th lk f th sprt, bt tht’s nt gng t stp ppl lkng fr gns. Rls r lwys pn t ntrprttn.

Trk Wrld Rcng pt Trcy Msly, Jstn Lv nd ndrw Nthlng n wnd tnnl bck n 2009, n 2016 Spclzd Grvty crrd t wnd tnnl tstng wth Lc Brn nd Lrs Vrgr, nd wh knws wht thr tms mght hv dn bhnd clsd drs. Clrly n n s gng t shr thr rslts, bt t wld b hrd t mss th mv frm shrts t fll pnts, nd clr trnd twrds tghtr fttng clthng, spclly whn rc rns cm rnd.

r thr stll rdynmc gns t b hd? Wll, tht’s wht wntd t fnd t, nd ftr rcnt pdcst psd wth Frml 1 rdynmcs gr, Tny Sltr, th dr ws pnd n wy t d jst tht. t trns t tht Tny’s x-bss hd bn nvlvd n sttng p sprts spcfc wnd tnnl nd Tny ws wndrng f knw f ny tms tht mght b kn t cm nd d sm tstng. ddn’t nd skng twc nd ws strght n th phn t Tny Sgrv frm FMD Rcng t s f h’d b kn t pt Thné n
  • 1 1
 What happend to your vogals ?
  • 1 0
 @Notmeatall: Canyon took them
  • 1 0
 @Notmeatall: Vgls gt rbbd
  • 1 0
 Are aero shoes coming too, just go full TT and call it a day!
  • 3 0
 It would be honestly scary to take the level of anal-retentiveness that the average mid-pack triathlete brings to his or her bike setup in search of aero-seconds, and apply it to WC DH racing. Whether or not there are real gains to be had, just suppose it became 'necessary' either through marketing, a well-timed 'scientific' paper, or just keeping up with the Joneses. NACA ducted down tubes, Kamm-tail fork sections, abandon the triple clamp, definitely no visors on helmets, tires that create a better frontal profile while not introducing drag through the complex rear triangle, internally routed everything cables, disc wheels. Then Gwin would drop a chain and flat a tire and still win.
  • 1 0
 Oh don't forget the drop bar!
  • 1 0
 Needs more lycra, alot more!
  • 2 0
 elbows out vs down
  • 1 0
 remember when Trek already did this?
  • 1 0
 I did reference their testing in 2009 in the story. Things move on though... testing never stops.
  • 1 0
 Looks like Canyon is coming up with new DH frame ?
  • 2 1
 this looks like it blows
  • 2 5
 these race kits are bordering now.please ban them getting any tighter.the sport is looking good for media and riders for god sake please dont get any tighter.
  • 1 3
 So that's whence the wind comes. Some say Seagrave already enjoys an advantage in torso aerodynamics. On to haircut.
  • 1 2
 Bring back skin suits!
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