Flo Cycling 2016 Wheel Line – First Look

Flo Cycling is no stranger to the pages of AeroGeeks.com. The FLO 60 was one of the first products we reviewed (and at the time, we said we “were smitten with this wheelset.”). And last year we reviewed the FLO DISC where we said: “If you’re shopping for a DISC and want a complete wheel that offers the best bang for the buck, the FLO DISC is where you should start, and end, your search. It is the very definition of Affordable Aero.”


But to be honest, in the three years we have been covering Flo, not much has changed in their lineup. Yes, they added the 30 to the original 60, 90, and DISC. But that has been about it … at least until now. Because starting today there is a whole new FLO lineup, and we are not just talking about new shapes and sizes. The team at Flo has decided that while the carbon\aluminum hybrid is a good option (and not going anywhere), carbon clinchers are where the market has gone—and Flo is going there too. But before we get into the new lineup, lets talk about how the brothers of Flo got there.

Building a Better Wheel

Beginning in 2014, Chris and Jon set out to build a better wheel. Yes, they knew the current model was good, but they wanted to do better. However, before they started working on a solution, they decided to ask the tougher question – what makes a better wheel? And following that up with the question of what kind of conditions are their customers going to face when riding?


To find out, they started building. Although they weren’t building a wheel. Instead, they were building a computer. Specifically, a computer consisting of a data logger – Onset Hobo Micro Station Data Logger, an Anemometer (for measuring Yaw Angle) called the Lufft Wind Sensor Professional Model 14521, and an Onset Wind Speed Smart Sensor S-WSB-M003 for measuring relative velocity. The final product was mounted to one of their bikes and then ridden on four Ironman Courses – Ironman 70.3 Silverman, Ironman 70.3 St. George, Ironman 70.3 California Oceanside, and Ironman Kona (Partial Course)—all resulting in 110,000 data points.


A few trends were immediately observed in those initial data points:

  1. The faster your relative velocity, the shallower the yaw angles you will experience.
  2. Until you hit 3mph, the yaw angle sensor swings unreliably.
  3. Drafting mimics slower riding. You still get relatively consistent readings, but there is more variance in the yaw angles recorded.
  4. When passed by cars, or moving into the wind after passing a structure, you see the sensor move to a dramatic yaw angle range for about a second before returning to normal.
  5. The yaw angle will move evenly from left to right in most conditions. Exceptions to this are during coastal rides where the wind is blowing onshore or offshore.
  6. Coastal rides produce a slightly higher set of average yaw angles.
  7. Most rides produce very similar results, regardless of conditions.


Additionally, when the data was combined from GoPro footage, they found that they could remove all yaw angle measurements that were greater than 20 degrees from the results. The reason for this was that when the videos were analyzed, the only reason a yaw sensor would produce a yaw angle greater than 20 degrees was in one of the conditions below (which are rarely seen in a race).

  1. The rider was passed by a car.
  2. The rider emerged from behind a structure blocking the wind.
  3. The rider was in a low relative velocity condition.
  4. The yaw sensor was stabilizing after experiencing any of the scenarios in 1-3 above.

So what did the final results look like?

Percentage of Time Spent at Yaw Angles


What you see is that 50% of your time on a bike is between -5 to 5 degrees of yaw. Roughly 80% of your time on a bike is between -10 to 10 degrees of yaw. Only about 20% of your time on a bike is spent between -20 to -10 and 10-20 degrees of yaw. The old belief was that 80 % of your time was spent between 10 and 20 over an even distribution, which is the assumption the original Flo wheels were built with. The new result is the complete opposite with a decreasing distribution over the range.

Percentage of Time Spent in Yaw Angle Range When Riding a Bike

With the new data came a new algorithm for aero optimization. For a starting point, Chris and Jon used the original Flo wheel shape. To that they “attached” the profile of a Continental GP 4000 S II in a 23mm size. To get the complete shape, they installed it on a FLO 30 with 100 psi. Flo chose the FLO 30 since it has an angled brake track, and the new wheels would all utilize angled brake tracks. They chose a 23mm size because it’s the fastest tire they had previously tested in a wind tunnel.


Flo then teamed up with CD-adapco to process the CFD. While the original FLO wheel shape was optimized on a single core processor in 28 days, the new shape took two months on a super computer (comparatively this would have been 1,334 days on a single processor machine). Each design was evaluated at four yaw angles, 2.5, 7.5, 12.5 & 17.5 degrees. For each yaw angle, the geometry was transformed by rotating the wheel, and then the model was re-meshed. The solver repeated this 500 times for each design at each angle. Each evaluation took two hours to complete on 32 CPUs.


The Results – Seven New Wheels

After months of modeling, optimizing, and time in the tunnel (we will get to that in a minute) the final resulting lineup is seven new wheels – four carbon clinchers (FLO 45 Carbon Clincher, FLO 60 Carbon Clincher, FLO 90 Carbon Clincher, FLO DISC Carbon Clincher) and three aluminum clinchers with carbon fiber fairings (FLO 60 Aluminum + Carbon, FLO 90 Aluminum + Carbon, and FLO DISC Aluminum + Carbon).

All wheels feature the new FLO Vortex 2 hubs. The Vortex 2 hubs reduced the weight of the rear hubs for the FLO 45, FLO 60, and FLO 90 by 50 grams and use 6802 bearings in the rear hubs. The front hubs feature the same 6900 bearings as the current lineup, and the hubs now have a matte black finish.

The new FLO DISC will feature a fully serviceable hub. If a spoke broke in the original FLO DISC, replacing the spoke was difficult. In the new FLO DISC, the hub has an access port that allows the spoke to be replaced.


FLO DISC Aluminum Carbon

All FLO wheels will come with Japanese EZO Stainless Steel bearings. Starting in 2016, Flo will discontinue their TPI ceramic bearing line. After testing, Flo was unable to show a performance improvement. And if you were familiar with Flo’s contributions to the Bike for a Kid program, don’t worry. Rather than donating a bike and helmet for every set of ceramic bearing wheels sold, Flo is now going to contribute 1% of their annual sales to the program.

FLO 90 Aluminum Carbon

FLO 90 Aluminum Carbon

Flo sent us eight wheels for initial testing – FLO 60 Carbon Clincher front, FLO 90 Carbon Clincher front, FLO 90 Carbon Clincher rear, FLO DISC Carbon Clincher, FLO 60 Aluminum + Carbon front, FLO 90 Aluminum + Carbon front, FLO 90 Aluminum + Carbon rear, and FLO DISC Aluminum + Carbon. While we are still in the middle of completing a full review, we did take initial weight measurements for all the wheels (in grams):

60F 90F 90R DISC
Carbon Clincher 760 890 1020 1360
Aluminum + Carbon 910 1080 1260 1370

Prices for the complete line are (in US Dollars):

Front Rear
FLO 45 Carbon Clincher $549 $599
FLO 60 Carbon Clincher $549 $599
FLO 90 Carbon Clincher $549 $599
FLO DISC Carbon Clincher $949
FLO 60 Aluminum + Carbon $449 $499
FLO 90 Aluminum + Carbon $449 $499
FLO DISC Aluminum + Carbon $649

And while we are not quite ready to share our initial impressions, we can say that the full carbon wheels feel incredible. Everything we would expect from Flo. We aren’t quite ready to say they have the stopping power of aluminum, but these aren’t the slippery fish we sometimes see with full carbon wheels.

Wind Tunnel Testing

So is the new line fast? Flo certainly believes so – and they brought their data to back it up. But before we get into the results, anyone who lives and breathes aero data wants to see the testing parameters:

  1. Tare was calculated and removed from all tests.
  2. A Mavic Open Pro with 32 round spokes was used as the baseline wheel.
  3. Each wheel was swept from 0-20 degrees of yaw, in 2.5 degree increments.
  4. The same tire was used for each test.
  5. The FLO DISC had the valve cover taped shut.
  6. Each measurement was taken twice and averaged.

Additionally, while Flo originally baselines 20 different tires, they chose two for their complete testing – the Continental GP 4000 S II in a 23mm size and Schwable Ultremo ZX in a 23mm size. Below are the results for each tire.

Continental GP 4000 S II Results Schwalbe Ultremo ZX Results

To calculate time saved, Flo uses a Net Drag Reduction Value. A NDRV calculates a weighted average for timesavings based on your time spent at certain yaw angles. With their 2012 wheel line, Flo considered 80% of your time on a bike was evenly distributed between -20 to -10 or 10 to 20 degrees of yaw, and the remaining 20% was evenly distributed between -10 to 10 degrees of yaw. However, based on their new data, they no longer believe this to be true. The new NDRV used the results from their data logger to calculate the average savings experienced when using the new FLO wheel line. As a baseline, Flo compared the NDRV results from their wheels to a NDRV for the baseline Mavic Open Pro with 32 spokes.

Continental GP 4000 S II NDRV Schwalbe Ultremo ZX NDRV

Wrapping Up

In sports as competitive as cycling and triathlon, it is all about marginal gains. When a company tells you their new product is 2-3% faster than their original, you take notice. When Flo tells us that their new FLO 60 Carbon Clincher is 22.20% faster than their previous model, you shut up and ask whom to make the check out to. With a price just $125 more than the original ($250 for the set), FLO wheels remain a serious performance bargain. Last year we called the original FLO DISC the definition of Affordable Aero. And with the performance of this new line, maybe we need to use the new FLO 60 Carbon Clincher and FLO 90 Carbon Clincher to redefine that phrase.

15 responses to “Flo Cycling 2016 Wheel Line – First Look

  1. Could you also get your hands on a Swiss Side Hadron wheelset? (I’m eyeing the 625-800+). It’s priced quite similar to FLO wheels thought a bit higher. I’m in the market for a 60-90 aero wheel combo. Aside from HED, only Swiss Side and FLO are the ones selling 60 and 90mm Alu-Carbon clinchers with HED being the most expensive of the bunch.

    • After buying a pair of Flo 60 last year, I reckon the Hadrons would be cheaper once you add on shipping, import tax and UK VAT. Might even be a better wheel? I regret not going for a 90 rear though.
      In USA, the FLO wheel is a no brainier though.

      • I have tried on some Planet X Alu 60-60 before on my old tri bike. Sold them because I can’t covert them to 11 speed when I got my P3. What’s your take for a rear 90? It’s pretty popular here in the Philippines together with discs (Zipp 808s, HED 9s etc).

  2. I think these are a very good product, and these will likely be my next set of wheels. They look fantastic, their testing protocol seems robust, and they’re very well priced.

    However their yaw angles are a little bit low I think. As they note, coastal courses (and those beside large inland bodies of water) produce higher yaw angles. Most triathlons are held beside the ocean, and most of the remainder are held beside large lakes, with large parts of the ride exposed to these conditions. However their testing has two of four locations (St George, Henderson) in non-representative conditions. That’s going to skew the data considerably.

    • Given that the real-world yaw angles observed by Flo is consistent with that observed and reported by Trek in its 2013 Speed Concept white paper, I would disagree that Flo’s selection of locations skewed the data considerably. (That, and large portions of the Silverman course is in the desert, largely simulating riding beside a lake as far as the wind is concerned.)

  3. i think i gonna sell my F6R and buy Flo 60/90 carbon. i have already the old flo disc. FLO all the way…

  4. any immediate thoughts on a Flo 60 set vs a Roval cl60 set? Pricing is within $100 and the weights are within 50 grams.


  5. PR – without comparative wind tunnel data or saddle time it is really hard to give a fair comparison. Anything else would be speculation. Hopefully in the not too distant future we will get a Roval CX or CLX set to do a complete test.

  6. How is the stopping power vs other carbon clinchers vs Zipp’s Firecrest ? Descending in the mountains while it’s raining is my only concern.

  7. I just read “Flo Cycling 2016 Wheel Line – First Look” and saw the assumptions they made about the percentages of time that people spend at various yaw angles and how it differed from their 2012 assumptions.

    FLO is trumpeting their statistics about yaw angles as if it’s a major revelation but it’s not. It’s been known for years that that the first 10 degrees of yaw (ie. angle of attack) are the ones that really count. And to professionals, it’s more like the first 5 degrees matter the most because of the speeds they go, versus an amateur athlete.

    But regardless, these kinds of assumptions have the effect of skewing the results as to which wheel is most aerodynamic over an angular interval, and allow all kinds of flimflammery. FLO is not the only ones only guilty of such foolishness; Zipp is as well. They will make assumptions about the percentage of time over the yaw angle range that makes their wheel look fastest.

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