Saturday, August 1, 2015

Buying Speed At A Discount - The Advent Of Everyday Aero

The last few years have seen, from my admittedly uninformed perspective, a revolution in cycling aero tech for the masses. Aero from the early '00s consisted of goofy lids, uncomfortable skinsuits, and heavy wheels. All, of course, at a premium price. But we seem now to have entered an era of improved aerodynamics at a reasonable price with few, if any, compromises.

Specialized has done a fantastic job breaking this down with their "Win Tunnel" youtube series, running everything from shaved legs to helmets to sunglasses through their wind tunnel and reporting the results in 'seconds per 40K', a unit that seems to be relatively constant regardless of rider speed.

As a conspicuous consumer with a cycling bent, I've been following this series and, where a bargain is to be found, picked up a few goodies to take advantage. Here's a quick summary of the testing they've done so far.

My reasoning generally is that going from 'non-aero' to 'aero' is a much bigger jump than 'manufacturer A's aero' to 'manufacturer B's aero'. So I figure that most of the results from the Win Tunnel apply broadly, not just to Specialized's specific products.


The only jerseys I've ever really ridden with are those I get from various events. Inevitably they're loose fitting, flappy jerseys. According to the win tunnel, I'm losing a lot of time with these jerseys.

Most of what I've seen on the line indicate that Castelli's Aero Race 5.0 jersey is among the "fastest". It's certainly far tighter fitting than my others! It weighs next to nothing. And is next to nothing; the material is sufficiently mesh to be able to see through it.

At 6'3" and 200 pounds, I need the XXL to avoid destroying the jersey while zipping it. Once on, though, these jerseys are just as comfortable as any other, and they don't look half bad!

Aero Bars

Aero Bars are a no-brainer for aero benefit. Honestly I can't remember the last time I equipped a road bike without them. For me they serve a dual purpose; a speed boost, and they relieve my wrists from having to hold me up for prolonged periods. In fact when I can't use my aero-bars for whatever reason I have major wrist problems.

The setup in the video above looks kinda silly to me. Way too far apart. But then I've currently got 40mm risers on mine which also looks pretty silly.


As far as I can tell the Win Tunnel hasn't done tests on wheels yet. But Specialized claims that the Roval saves about 44 seconds over a non-aero wheel. Of course the results will vary greatly on what kind of wheel you use. I opted for the budget Shimano RS81 C50.

Which, since I hate extensions, also necessitated picking up a passel of new tubes. Fortunately Merlin had me covered with a good price on a 10-pack.


As you'd expect, Specialized is going to compare their aero helmet with a standard road helmet. They found a savings of 40s from an Evade over a Prevail.

But Bike Radar's tests showed that the new Bontrager Ballista is even faster:

I went with a high-viz yellow Ballista, which matches my Castelli kit nicely.

Unlike the older aero road helmets, the new ones don't look too bad even from a side profile.
Specialized Prevail vs Bontrager Ballista


I couldn't find a Win Tunnel video on this, but elsewhere I see claims that the Specialized S-Works Sub 6 shoe saves 35 seconds over the standard S-Works shoes. I ride with Shimano sandals...

I wonder which is faster. This:

Or this:

If the savings over a standard S-Works shoe is 35 seconds, I bet the savings over my sandals is closer to 60. Or more. The problem is I'm not ready to make this jump yet. I love my sandals. In fact I have an extra pair of them for when my current pair finally dies. Moreover any aero road shoe will require me to use road pedals, and I've standardized on eggbeaters across the bike lineup. Switching either requires me to introduce a third pedal type into the mix (flats for mtb, eggbeaters for rain bike, etc..., and 3-hole for fast), or switch about a half dozen bikes over to road pedals. That's not cheap.


Ah, shaving. The Win Tunnel doesn't lie. On the Specialized 'Chewbacca' scale I'm probably a 6 or a 7. Shaving my legs would likely get me 70 seconds savings over 40K.

Shaving my arms could get me another 20 or so:

But... Then I'd be a guy who shaves his arms and legs.

That said, I'm going to suck it up and try it. The apparent benefits are huge, and the price is right. I have no idea how to shave legs, but I guess I'll figure it out.

Intermediate Results

I have a route that I ride frequently, a 21 mile out and back with a small gradual ~800 foot climb and descent. I use this for my FTP measurements, and I use Strava with this segment to judge my fitness relative to everyone else.

I created a 14.4 mile segment from this that includes just a portion with (almost) no artificial slowdowns.

Realizing that this is, scientifically, a completely meaningless comparison I proceeded to compare anyway my average power and speed over this segment from a handful of rides over the last few months.

Date Watts Speed Gear
Aerobars, Castelli Jersey, RS81 C50, Bontrager Ballista
Aerobars, Castelli Jersey, Bontrager Ballista

When I say meaningless, I mean it. Since March I've dropped 30 pounds. The later measurements are on a different bike. I swapped my Powertap for a Stages. Really noisy data. That said, I feel moderately confident based on both the data above and my perceptions while riding that the newer aero gear is giving me about a 1% - 2% speed increase. That might not sound like much, but ride as hard as you can for 20 miles and then ask yourself if you'd have been able to go 0.2 - 0.4 MPH faster. That's about what the aero gear is providing.

Future Work

I always ride with a saddlebag. A big, bulky one with tools, levers, cell phone, wallet and two tubes. That can't be great (or maybe it can? I'll need the Win Tunnel to tell me!). I can probably fit most of that in my jersey pockets.

I'll try shaving my legs for science. It'll grow back, I suppose.

And shoes... Sigh. I've never tried real road shoes. I guess at some point I should.

Of course the least 'bang for the buck' is a frame. Even Specialized acknowledges that the Venge gets you only 60 seconds or so, and that at a considerable price premium. I doubt an aero frame is in my future.

1 comment:

Max said...

This is awesome. Ballsy call on that helmet and kit. I mean it.

Shaving: you can get 95% of the benefit without putting a blade on your skin. Just get the electric hair trimmer and run it without a guard up the leg. You cut down to a minimal stubble. It is painless and only gets annoying after a few days of growing back, when you will want to trim again.

Bike looks good thusly built up. Nice work. Too bad, of course, that the frame is on the wrong side of its half-life.

And, with those numbers, I am looking forward to seeing the results of your century tt. When is that scheduled?