FLO Cycling G700 – Why You Should Run a 55mm Wheel for Gravel

One of the hallmarks of a good gravel wheel is a wider internal width to support the wider tires you typically see, even wider than cyclocross. Most of these wheels tend to be in the 30-40mm height, but why does it have to be that way? Why can’t you have an aero gravel wheel? FLO Cycling knows you can, and I haven’t been riding anything else since I tried them.

This isn’t our first review for FLO, so check out the 64 AS Disc review as well. While the AS is the road wheel, the G is the gravel wheel. Like the AS, it features a full carbon rim, 24 Sapim X-Ray spokes front and rear, and FLO Vortex 3 hubs, with the rear accepting Shimano/SRAM 10/11, Campy, and XDR. One big difference is the G Series only comes in a disc brake version.

Another area that separates the G from the AS is the rim dimensions. The G only comes in one height per diameter, 54.9mm for the 700c, 58.8 for the 650b. Internally, they are both 25mm wide, and 33mm wide externally. That’s an extra 4mm internally, and almost 5mm externally. The 700c recommends a 32-50mm tire and the 650b can handle down to 32mm, but 37-50mm is recommended.

To read up more on what went into the G series, check out FLO’s blog posts here, as they go pretty in-depth about the design and construction of their wheels. It’s a great place to go if you want to geek out for a bit.

“Dirty Aero”

Here is my theory when it comes to “dirty” aero, and something that I have thought about for a long time. First off, when I say “dirty” aero, I’m talking about cyclocross, gravel, heck, probably even mountain biking; aerodynamics for disciplines that are slower, dirtier, and not on traditional smooth surfaces like the road.

Aero is important any time you are moving forward, regardless of how fast you are going. The slipperier you can be, that is one less thing you are pushing against when moving forward since you are moving through air. Another way to think about it is if you were walking along the bottom of a pool. You are pushing your way through water as you move. Air is similar in that it completely surrounds us, so we are always pushing our way through it. Cars, semis, planes, trains are all made to be aerodynamic to make them more efficient. As a cyclist, you already have friction from bearings, your drivetrain, and the ground, so by reducing the aerodynamic drag on you and your equipment, you become more efficient, helping you go either faster or further with the same amount of work.

In cycling, aerodynamics started with time trials and triathlons, before moving to road. “Dirty” aero is starting to catch on a bit with gravel due to the long distances that you typically ride in events, and the racing becoming more high profile. You see it a little in cyclocross with some riders using deeper carbon wheels or aero road helmets with their skin suits. Even cross-country mountain bikers have embraced traditional spandex kits, skinsuits, and aero helmets. For gravel, bags and packs are still a challenge, but some brands have embraced this with specially made packs that are designed specifically for their frames and mount with bosses instead of straps to be as aerodynamic as possible.

3T was one of the first bike brands on board with this concept with the Exploro. Five years on, it is still one of a handful of aero bikes out there for all-road riding. Check out our article with a deep dive behind their thoughts on slow-speed aerodynamics, along with the effects of mud on the tubing. One of the things that was missing at the time was a true, wide internal width aero wheelset to handle gravel tires, and allow them to fit and shape properly to decrease rolling resistance. A few more bike brands are embracing dirty aero, but FLO is one of the few brands embracing it for wheels.

Riding the G700

Just like the 64 AS Discs, I spent a significant amount of time on the G700’s. This took me across plenty of miles of road, rail trail, gravel, and even some doubletrack. My test rigs were my trusty Van Dessel Full Tilt Boogies. The Boogie has always been the brand’s race-focused cyclocross bike, but as with many CX bikes, it has found double duty as a race-worthy gravel bike. It isn’t an aerodynamically focused design, but it helps to show that adding aero wheels will help improve performance, even when you are going slower. I wrapped the wheels in 700×40 WTB Byway, 700×38 Schwalbe G-One Bite, and Donnelly 700×40 Strada USH WC tires for various events. All were run tubeless with FLO’s tubeless tape and valve stems, and either Effetto Mariposa Cafe Latex or Finish Line Fiberlink tubeless sealant

First impressions were good. The G700’s felt like they spun up just a touch slower than some of the lighter wide wheelsets I’ve ridden, but once up to speed, they held it better. At 1,891g, they are a little on the heavier side, but not too bad for their height and width. For comparison, the Zipp 404 Firecrest Disc wheelset weighs in at a claimed 1,820g for the pair.

On the road with the Byway and Strada USH WC’s rolled over smooth to broken tarmac comfortably and carved through corners on rails. When standing, there was little to no lateral flex in the wheelset. On gravel, they shined. During unPAved Susquehanna, they carved through the rocky “Difference” descent at speed with the G-One Bite with all the confidence that I could muster of my not-so-great offroad skills, especially when I took Obi-Wan Kenobi’s advice and “just let go” of the brakes and let the Force help me carve a line at speed.

There is more to the G700’s comfort though. While FLO worked to optimize the carbon fiber layup to help dissipate vibration before it can make its way to the rider, there was also a benefit they never saw coming from the design of the rim shape. The rim acts like a leaf spring, a type of suspension you find on a lot of trucks. Essentially, it is a piece of material that is fixed at each end, with another fixed point in the middle where the load is applied. When load is applied, that material will flex. A good carbon wheel acts similarly. Yes, the tires will flex, and spokes will flex too, but when you look at the cross-section of the rim, you can see where it has two fixed mounting point and then the spoke is the central mounting point. The thin carbon walls will flex a small amount, creating the leaf spring. This is something you won’t find on aluminum wheelsets though because the material is too stiff.

The bottom line with the FLO Cycling G700 is that it is a solid gravel wheelset for anyone looking to add a little speed to their ride. Just like the 64 AS Disc, I decided to buy the wheelset, not something I do often, and only when I truly love a product. It handled everything I threw at it, and helped get me to the finish of many long gravel rides, faster than I would have on some of the other gravel wheelsets I have ridden.

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