Aero Gravel Wheels: A Case For And Against

 As most of the cycling nerdom knows, aerodynamics play a big part in getting speed and efficiencies optimized for speedy riding. Yes, not everyone needs or wants aero, but if you want to make riding gravel a bit easier, aerodynamics is a good place to start. 

Aero can mean position on the bike, clothing, or in the design of the frame of your bicycle. But perhaps no upgrade in aero can make more of a difference than wheels.  Both in aero and in rotational weight, with even a nod to comfort. I think body position can get you the best gains, but as far as multi-benefits go, the wheels give you more. 

I've been trying out aero-focused wheel sets on gravel since 2012, well ahead of most folks, and so I have experienced what the wheels with aero design can do for your ride. Now with racing driving the development of gravel, aero wheels are becoming even more of a forefront thought in rider's considerations for upgrades. 

It hasn't been this way until very recently, as far as gravel riders go. As I found out in 2020, when I tested FLO aero gravel wheels, many were dismissive of the deeper section wheels and their aero benefits. This despite evidence from triathlon and road racing which clearly showed how much aero wheels can benefit a rider. Any rider, not just racing athletes.  

The Case For Aero Wheels: Besides cutting through the air more efficiently, which is what most aero wheel documents will focus on, there are a few other things which should be thought about. One is rider fatigue. Depending upon the design, a rider can benefit from less effort in crosswinds, and working less to keep momentum and stability intact is going to result in a fresher rider over a certain distance.  

But other factors, like design in the rim itself, can also contribute to comfort levels. The FLO Cycling wheels I tested actually had a flex component which absorbed vibrations, an obvious benefit on crushed rock roads. Many wheels are now also going to wider inner rim profiles, which match wider tires gravel riders are using better. This not only enhances the aerodynamic properties of the wheel/tire combination, but it also allows the rider to use lower air pressures to obtain an even smoother ride. 

NOBL Wheels Far 50. Image courtesy of NOBL Wheels.

 Weights of aero wheels have been getting better, but also consider that a lighter/lightest wheel often is not the best wheel overall. Perhaps in a specialist category of hill climbing, the lightest wheel set wins. But older and more recent wheel testing has shown lighter wheels can suffer from being harder to hold momentum over smaller deflections and obviously, over larger inputs like gravel. 

A heavier wheel, to an extent, can actually be faster with the rider expending less energy due to the momentum effect of the wheel. If the wheel is not being deflected, but carrying energy over an input from the surface, you need to do less work. Kind of like a crankshaft counterweight, or a flywheel. 

Obviously, too much weight isn't good either, but going deeper and a bit heavier with rim weight shouldn't be looked at as a negative in many aero wheel cases.  

The Case Against Aero Wheels: Not everyone will benefit from aero wheel sets. If you ride what essentially would be described as single track with a gravel bike, the benefits of aero could be lowered to almost having no effect. Especially if you ride a lot of trail with heavy deceleration zones requiring a lot of acceleration back to speed. Weight, and where the weight is on a wheel, may become an issue there. And again, perhaps with a more hill climbing course, aero may not be of much benefit on those types of courses. 

The Singular Albatross. (Image courtesy of Singular Cycles)

However; the big unknown here, and which may be a big factor in what you want to do with aero wheels in the near future, is the 32" wheel. 

This wheel may take over as a major option for gravel riders. I've heard from several sources that the 32"er will become a thing in gravel racing/riding. So, this is not speculation. 

What is still up in the air are things like hub width standards, and ultimately what width tires will be best for gravel on a 32" wheel. Theoretically, since the tire contact patch is longer than what a 700c gravel tire has, one might be able to get away with a slightly narrower 32" gravel tire. This might allow for the same/similar rider comfort and control benefits with a similar weight to a wider 700c tire on a gravel bike. Also, this would help with frontal aero concerns. 

With those questions all hanging out there, does a gravel rider bank on sticking with 700c and risk not getting the potential benefits of a 32"er, or does the rider bet on 32'ers and then find out it was all just a flash in the pan? 

I think if it weren't for the tantalizing possibilities of 32" wheels, just getting a 700c aero gravel wheel set is a slam-dunk. Maybe it still is. I would guess so if you are dead set against 32"ers, or are well under 6ft tall. 

Conclusions: Obviously, many riders are invested into standards surrounding 700c and are not in a position, or willing, or both, to switch over to something new - and as yet - unproven. So for those riders, getting an aero wheel set makes a lot of sense. I really see no negatives which would compel me to not want an aero 700c gravel wheel set. Especially since companies are now starting to develop wider internal width choices in aero rims. 

I know the old and tired argument which states that if you are going under "x miles an hour" you do not need aerodynamic wheels. I say phooey! In my mind, if you are moving aerodynamics matter. Maybe to a lesser extent at 12mph than at 25mph, but it matters, and this is enough for me to consider aero wheel sets for gravel riding.