I am actually flying back home through Toronto on May 6th and will have all my gear post Wildflower...May 7th could be fun, but I think work related obligations will get in the way. Really curious to see the outcomes. Will you have a thread on ST showing what was done etc?

Dev

Sure, we will definitely summarise the results!

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AndyF
bike geek

I would like to know when you have another round and will push it out to the Ottawa aero geek community. This is great for serious guys who don't want to travel an entire continent to get to the LA Velodrome. My neck is also getting better (accident 4 years ago) and I don't get headaches with more weight on my elbow pads from riding forward so would be curious to try various positions that are sustainable (for me with my bad neck and post concussion symptoms) and see aero trade offs. Right now I am shooting in the dark to some degree. I have a had to go wide (elbows only slightly narrower than hips, but hands together), high, and back.

Side view from a few years ago. Saddle is slammed all the way back in the rear hole of a Cannondale Slice. I am riding a bit further forward and slightly lower, but still need my pads super wide or my neck gets "pinched" and I get headaches. Wide pads allow me to drop head between shoulder blades. When the pads are tighter my head sits higher....changes to Evade for head down riding....but all of this still shooting in the dark using field tests on a local hill.

Most likely, this is the last set of aero tests that we do before September. The velodrome temporarily becomes the property of the Toronto 2015 PanAm Games on May 15th.

The $479 price is also just for early May, btw.

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AndyF
bike geek

Andy,

Best wishes with this.

I road the track for the first time last week. It was a blast!

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Steve Fleck @stevefleck | Blog

It's a beautiful track!

Hope to see you there, Steve...

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AndyF
bike geek

Sounds great Andy. I met you at the track a few months back when you were doing some testing for the national team riders, glad this is going to happen before it shuts down for the games. A couple questions - price in USD or Cdn? I just signed up on your site for the Thursday session - looking forward to it!

It's $479.00 cdn. That's a big discount! :-)

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AndyF
bike geek

Just an update for this round of aero testing...

GTA Slowtwitchers are invited to come and see our aero testing in action. We will be busy putting customers through, but there's always time to say hello. Introduce yourself, and we can talk after the testing is over.

Test dates and times:
May 7th:
1:30-8:30pm

May 9th:
8-10am and 4-8pm

See you in Milton!

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AndyF
bike geek

Well, I promised I'd let you in on some of the riders' aero improvements, with their permission. We had the good fortune to have Frank Mizerski, Retul Master Certified fitter at Racer Sportif, to help us out. Frank made sure that I never stretched Marc outside of what was biomechanically sound. Thanks, Frank!

We also had Slowtwitch's own, marcag, in for testing on one of the days. Marc's one of those techie Slowtwitchers who understands the equations and has been following Slowtwitch's "best aero practices guide" for quite a while. I'm sure he has a direct hotline to Jack Mott's home phone or something. :-)

Marc was a good enough sport to allow me to publish his testing. There was a bit more testing and fitting than what I describe here, but I wanted to give you the general trend. The whole thing took 3 hours, and was done in tandem with another rider. While one tested, the other got wrenched on the apron of the track. 60 minutes per rider is good enough to get some results, but we recommend 90 minutes per rider for tandem testing.

We started out with a baseline run of 0.294 m^2 which, given Marc's position and equipment, didn't make sense. But a close inspection of his helmet revealed that there were huge gaps between his face and his Giro Advantage 2. The straps were very loose and overlapping the outside surface of his helmet. You could almost hear the helmet whistle by as Marc raced. I remember telling him, "C'mon, Marc, that helmet is a frickin' mess. Clean that up!" Marc's very next run was a 0.276 m^2. Perhaps a bit of it was due to some slightly smoother riding, but this was the start of his aero improvement.

Lesson 1: Clean up your helmet straps and choose the right size helmet.

The next set of laps tried to get him more reach, but this didn't help. It was at this point that I noticed that his basebar was angled up slightly, at probably a 15deg angle of attack. So we levelled the bars, with no significant change to his CdA.

The next attempt was to try to make Marc's arms more parallel to one another, rather than having that awkward triangle shape. The armpads were moved 5mm to each side, and the saddle was moved forward to allow Marc to reach his grips a bit better. Result: 0.264 m^2.

Lesson 2: When it doesn't increase your frontal area, try to keep your forearms parallel to one another. The frontal projection of your arms should remain within the outline of the rest of your body (hips, legs, etc...).

After a few minor tweaks, we were all pretty happy with the comfort and aero-ness of Marc's positioning, so we turned our attention to suits. Marc started with an Orca RS1 one-piece, with lots of shoulder showing. So we tried a quick change, putting the LG Course Tri Top directly over the DeSoto Forza ITU suit, with disappointing results. A complete change, with cycling shorts and the M2 Top gave us an impressive 0.256 m^2.

Lesson 3: Skin is slow! Translation: Cover your vertical cylinders.

Finally, we tried a shrug test to see if the position and equipment could be improved by posture. Sure enough, a gentle shrug gave Marc an 1-lap CdA of 0.242 m^2. Obviously, this is not something that he could hold for an entire Ironman, but it could certainly come in handy in a strong, momentary head wind. We usually try it to see if repositioning the rider might help the shrug be more comfortable and sustainable.

All in all, not a bad day's work for Marc. He rode very consistently, and his cheerful manner made the testing very pleasant.

Thanks, Marc, for testing with us!

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AndyF
bike geek

Thanks to you and marc for sharing. Great read and from a local source for me. Hopefully, you'll be back in the area soon.

I also had a testing session with Andy and crew, and would most definitely recommend to anyone interested in getting more aero.

The session was a significant milestone for me, as it was the first time I got on the track after breaking my femur in a training accident 2 years ago (almost to the day). Nervous at first but it didn't take long to get comfortable again. I think Andy was as happy as I was at getting back on the track.

My position was pretty well dialed in, but we were still able to get me some more speed. Without spilling all the details, I'll echo what Andy says above -- helmet matters, head position matters, arm position matters ... and tires matter. Some of it is of course personal ... so testing makes the difference. I knew what I wanted to do in advance, and was pretty efficient with making the changes, so we got a lot of data in the allotted time.

One thing to note: make sure your bike is in a state where you can loosen bolts, move your front end around, etc. You don't want to show up with a frozen seatpost, frozen aero bar bolts etc.

All in all ... it was a great session. The Milton facility is beautiful, and Andy and crew were great.

Anyone who wants answers should test. You can't get the answers reading here. Case in point, one of the helmets Andy found fastest on me has completely exposed straps, while one helmet that tied it had almost entirely enclosed straps. But, that's me, in my position, with those helmets. We have preconceptions based on patterns, but the data is. Also, testing cothing choices, on the track ruled out uncfortabe products and gadgets that were good in theory but unusable at race speeds or effort level.

Good point, Damon.

People always want to know what equipment is best, and we always say that each person is his own puzzle. Perhaps there's value in just understanding what the testing can provide, though. Honestly, the minute I think I know how someone will respond to changes, I get humbled. Sometimes even humiliated. :-)

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AndyF
bike geek

I agree, testing is a must. As Andy mentioned I had done a lot of testing on my own. I had tried all types of protocols and software and while I could get results, consistency was really difficult. To do it to the resolution Andy is able to measure is nearly impossible.


When you test on your own, you can tell when everything is good, or when things are terribly bad. But to pinpoint problems is hard. When I did my first run at Milton, something was "terribly wrong", and we were able to pinpoint very quickly. It was "no way you are a .295, fix that and let's retest".


In field testing, there were many things I was able to determine on my own, For example, which helmets seem faster. But getting accurate, consistent results is really hard. When things are "borderline" one wind gust during a test throws things off. However, things like widening my arms was consistently faster when I field tested and something Andy's technology/practice confirmed.


The whole helmet thing was a combination of straps, sunglasses, plugs…..very difficult to figure out outdoors. Almost impossible to figure out which element made the difference.


One thing this round of testing helped me confirm one of the models/protocols I have been using is pretty good. I had measured a high .26x at one point. It was with a setup very close to the best run I did at Milton. Now with a baseline I can, in theory, confirm my baseline and try things on my own, and always come back to my baseline.


Before people go out and buy a bunch of stuff, I think it's money well spent to figure out where they are, what can be fixed with some tweaks and then decide "what's next" scenarios. I came out of the session knowing that the equipment I owned was as good as what I could buy. For example the LGP09 was the same as my Giro, but if used with a Visor and plug, would have actually been slower. So I could have gone out, spent a few hundred bucks on a helmet, use the visor and get 0 benefit. All I need to do is be meticulous about the strap and wear sunglasses with my existing helmet.


I think there is more to it than just great technology to do the measurements. Andy is very methodical, has a great eye and of course tons of experience. That makes all the difference in using the valuable time efficiently.


And BTW, it's a ton of fun.

The eye is a poor wind tunnel because CdA is invisible. Testing makes the invisible visible.

Exactly. Most of us can do gross levels of testing but if you want to distinguish small subtle differences it helps tremendously to have someone experienced helping you out.

Well...it can't be that bad of a "wind tunnel", since by eye Andy knew that his helmet setup was a mess ;-)

But yeah...there are more precise and accurate methods of determining "aero-ness". However, the old "eyeball wind tunnel" usually does a fairly decent job of at least getting one in the ballpark.

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http://bikeblather.blogspot.com/

Don't worry, my eyeballs are wrong more often than I care to share with you. Optimizing is a series of wild guesses that you validate by testing. Sometimes it's hard to imagine how such a subtle change can make such a big difference, and other times you can't believe how un-aero something is, even though it looks amazing. Heck, I'm still learning and I imagine I won't ever know enough to be right every time. :-)

The flow separation point, for example, on the back of a human riding a bike is something very tricky. Jim Manton mentioned that it's the interaction of position/helmet/suit that makes a quick combination. Get any one of those wrong and it's aero trouble.

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AndyF
bike geek

I was speaking to Andy yesterday (or the day before, can't remember which), and told him something that I like to tell a lot of people these days...

When you begin working with good aerodynamicists, the one thing that will strike you is how humble most of them are. It's almost to the point of frustration because you can't get them to give you any kind of definitive statement on anything aero. It drove me crazy at first. "Just give me an answer!" you want to exclaim. None will come. As I've been educated over the past few years conducting who knows how many hours of testing, I now understand the humility; it's born out of humiliation. Aero testing will slap you down down very quickly because, the moment you think you know is the moment you'll be reminded you actually don't know. Aerodynamicists are humble because, like all good scientists, they know the proof is in the data. Guessing will only make a fool of you. You must test to know. When possible, test twice, 3 times, 10 times if you can. Then you have an answer...but only for that athlete. ;-)

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Jim Manton / ERO Sports

Aero athletes are all alike. Each un-aero athlete is un-aero in his own way.

Zactly!

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AndyF
bike geek

This really was the highlight of my day! Just to give you a feeling for the emotion of it, here is BrianB after a triumphant return to the track. For any of you out there seeking motivation, this is the picture of you, the loyal Slowtwitcher, winning out over all kinds of adversity!



Anyone, try not feel super stoked after looking at that pic! :-)

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AndyF
bike geek

Makes me wonder sometimes about guys beating me sometimes. Are they better "athletically" than me or are they just "naturally" more areo than me.

I'm sure it's a combination of both , but some how it's easier to accept being beating athletically than it is to be beaten by some dude who is just naturally more aero than me or lucky enough to have stumbled across the right equipment for his body/riding style. It messes with my head.

As they say it's good to have good genes if you want to be a good athelet. Maybe aeroness is just in your DNA as well. Something else to talk to my parents about.