Wednesday, December 14, 2016

Aerodynamics for everyone!

Originally written for Mind Right Endurance, who I'll be partnering with this upcoming year to try to help with making everyone faster on the bike! 

First, thanks to Mind Right Endurance for reaching out to me to do this!

(I'll try to keep this as beginner friendly as I possibly can.)

   So you want to go faster, but you aren't quite sure where to start. Maybe you've started, but you're mired down in the seemingly endless amount of white papers, drag savings, yaw angles and other information out there. Or maybe you're just looking to squeeze out that last little bit of "free" speed.

   First, for this discussion you need to know the context. I will be talking about a triathlon or TT bike, not a road bike. It's just easier when we draw the line somewhere and that's as good of a place as any. That's not to say aero positions can't be achieved / improved on road bikes, just that it opens up more doors than this discussion will have scope to deal with. The other disclaimer I'd like to put out there is that these things are VERY personal. What works for me, your coach, your neighbor, Bradley Wiggins or 99% of the people that go through a wind tunnel does not necessarily mean it will work for you. Of course if you aren't able to test for yourself it is best to pick the things that test well over a broad spectrum of people and hope that you are in that majority. It's always best to test for yourself however. Therefore, We (Mind Right Endurance and myself) are starting an Aerodynamic Consulting Service to personalize your equipment for your fastest results yet. If this interests you, please don’t hesitate to reach out and ask questions!

Things most age groupers can do to gain free speed.
   This discussion will be primarily about equipment choices. However, I wouldn't feel right without mentioning exactly how important position on your bike is. It is the single most important thing to make you go faster. My advice is to either find a bike fitter who understands the unique needs of an athlete looking to go faster, or be willing to dedicate a lot of time making tweaks yourself.

Equipment choices

   We'll start with the one that comes back to "you." More importantly, what you are wearing. The problem is skin is slow, so if you can cover it with an aerodynamic material, you'll go faster. The tricky part is that as slow as skin is, wrinkles in fabric are usually worse. That means you want clothing that absolutely looks like it's painted on you. It is fairly easy for time trialists, you find a skinsuit (the Castelli Body Paint has been a competitively priced option that tests well) that doesn't have a lot of wrinkles when you are in aero. For triathletes it becomes quite a bit more complex, as you need to be able to swim and run in the suit as well. Recent rule changes have allowed covered shoulders in triathlon, but many still constrictive to swim in an aero suit. Your individual body will make a lot of difference, but often this one comes down to whether or not the tradeoff's are profitable (say you'll be slower swimming, or in transition, compared to how much faster you'll be on the bike split...) The one piece of advice I'd give to most serious age groupers... at the very least get a one piece kit. The split in a two piece kit when bent over in aero is almost always bad for aerodynamics.

   Your actual whip will be another important choice you make. While my go to answer to any questions on "which bike should I buy" is "the one that fits" there are a couple of other questions to answer before pulling the trigger. I classify bikes in three categories... superbikes, (Trek Speed Concept, Cervelo P5, Canyon Speedmax) proven bikes (Cervelo P2/P3, Specialized Shiv/Transition, Trek Equinox) and unproven bikes. (Planet X, Most "Chinarello" frames, Falco V bike) Of those, I would always suggest going with one of the first two categories unless price is the absolute determining factor. Even then, I'd prefer a used P2/Equinox/etc to an open mould frame. In my mind the primary thing that separates Superbikes from proven bikes is integration, particularly in the front end and cabling. Superbikes are made for people that have mechanics on hand to work on them and keep them running. If you aren't a handy mechanic yourself, you need to weigh the pros and cons of having a bike that you may not be able to work on / adjust / fix in a moments notice. As far as the aerodynamics go, most of the "big" brands have put some effort into making their bikes pretty fast. Most of the offerings nowadays should be on par with a P2 or P3, which was long the benchmark of aerodynamic frames. (And for what it's worth is still an excellent choice)

   If you aren't restricted by bar choice (having a superbike for example) then I think having something adjustable but still slippery is often an excellent idea, especially if you haven't absolutely nailed down your pad stack and reach. My go to suggestion is the Profile Design Svet series for a base bar and the excellent Zipp Alumina clip on bars. This will give you a pretty fast setup with lots of adjustment possibilities while still allowing you to use any stem. If you do have your position nailed down and are looking for the fastest bars out there, there are many good options these days. The Tririg Alpha bars and the 3T Ventus are some of the slipperiest options out there so long as you don't have to conform to any UCI rules. (Triathletes do not, nor do most time trialists) Good UCI legal bars include the 3T Brezza Nano's and the USE Tula / R1 aero bars. For someone on a tighter budget, the old HED aero bars (they did not have a catchy name) and some of Vision's older offerings are fast and widely available.

   While the helmet can be very personal with regards to your own riding style, there are some clear options out there if you are just buying one without personal testing. There are also some helmets that are often stinkers. Helmets that often test very well on a wide range of people are the Bell Javelin, the Giro Advantage2 / Selector, (also likely the new Aerohead) the Specialized TT and the POC Cerebel. Helmets that often test poorly on a wide array of people include the Lazer Tardiz, the Rudy Wingspan and the Kask Bambino. So if you aren't sure what helmet to get, I tend to think it's hard to go wrong with the Advantage or the Javelin, as they can be had for under $100 all over the internet, so if you decide it's not the best for you you'll not be out a fortune.

   There is so much data on wheels on the internet it's hard to know where to begin or end. My biggest issue is with no-name off brand ebay wheels (or re branded ones, which is now common.) The problem with them is although the price point is enticing, there is almost never any aerodynamic research put into them. That means you are often getting a wheel that looks very fast, but may not be much (if any) better than your training wheels. As a bang for the buck buyer, it's hard not to look at FLO cycling and think it's the best deal on a new set of wheels out there. Real data, well made and reasonably costed. Of course HED and Zipp make well tested and very nice products, as well as quite a few other companies at varying price points, and the used market is alive and thriving. Wheelbuilder and a couple of other companies also offer disc wheel covers for your spoked wheel, which can be had for under a Benjamin. Personally, I almost always suggest somebody takes their budget for wheels, buys a Powertap (considering they don't have a power meter of some other sort already) and a wheel cover, then buys a moderately deep front wheel.

   Wheels (in the context of going faster) should never be mentioned without giving credit to tires. I won't go into tire selection for racing too deeply, but there are plenty of free resources (Biketechreview and Tom Anhalts blog to name a few) that measure rolling resistance in tires... there is little point in buying a fancy set of aero wheels only to run them on Armadillo tires.

   For time trialists there are not a lot of options. You are fairly limited to whether you want a bottle on the down tube or the seat tube, and then whether to use a round bottle or an aero bottle, or no bottle at all. All of those options are viable depending on the distance of your race and your specific frame. For triathletes it's much more important and complex, both because you aren't limited by hydration options and also because your time on the bike (and racing in general) is going to be longer. My main advice in the hydration category is to be realistic and honest with your abilities. Saving a few watts with a slick bottle placement won't be worth much if it causes you to under hydrate because you don't use it. That said, an excellent go-to choice is the "torpedo" bottle placement. It tests generally neutral and sometimes positively for most people and it places the bottle right in front of you, making it hard to forget about. Another good choice is something like the Torhans system, which again is right in front of you to remind you to drink, and is also often very fast testing. (Some reports even hinted thant the Aero 30 was faster than no bottle on some Superbike front ends if set up very close to the head tube) The good thing about both of these options is that you can re-fill at aid stations. Bottles behind the saddle are sort of hit or miss, often requiring very tight placement to keep them out of the wind. Frame bottles come in varying sizes and shapes, and again, whether you use round bottles or a dedicated aero bottle should depend on the distance and your comfort. The one thing to always remember is straws sticking up are generally not good. Torhans address it with a fairing, and other companies often include a magnet to keep it held down... I think all of that is fine, just don't have a round shape out in the middle of the area in front of your face.

The little things
   The Xunzi speaks on the death by a thousand cuts... and while not quite as torturous, sweating a lot of small details can often lead to big gains. These are things like smart cable routing on non-integrated frames/bars, number placement, aero brakes and chainrings, smooth shoes (Pro triathlete Thomas Gerlach has lately been advocating modified Giro Empires as very fast shoes) and even shaving. 

   While I don't quite believe that shaving your legs can gain you 20+ watts, I do think there is likely some benefit there. Cables out in the wind and poorly routed can often be costing you precious seconds, and will both make the bike cleaner, more efficient and faster. I've had excellent success in the past making very slick non-integrated cable routing using cable systems like Nokon's links. Shoes are certainly something that can make a big difference, large buckles and straps (and even boa dials) sticking out in the wind is surely not as good as a cleanly profiled narrow shoe... however again you need to figure out if the speed you will gain by swapping shoes will be negated because of increased difficulty getting into them. Time trialists have it easier, as we can use shoe covers. (Velotoze are cheap and usually good) The days of poor stopping, rare aero brakes (price an old Hooker brake some time) are thankfully behind us. Tririg is leading the charge with the excellent Omega series, and for a non-integrated front end it's high on the list of recommended upgrades. Aero cranksets/chainrings don't have a lot of definitive data on benefits, but they likely help a bit and of course, they look cool. (which is very important as well)

   There is of course so much more... wheel and tire interaction, where and how you hold your hands and head, saddle height, cockpit height, bar angle... more than you can feasibly put into a post like this! Maybe next time. Hopefully you found this post at the very least a little entertaining, and who knows, maybe you will pick up a little free speed!
Check out Mind Right Endurance for more tips, personalized coaching, and help optimizing your bike setup!

Until then, thanks so much for reading, I really appreciate it!

- Christopher Morelock

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