Aero Bike Wheels Summary: If you ride on flat and rolling terrain at average speeds above 20mph/32kph or do crits, time trials, or other road races, an aero wheelset will help you increase and maintain your speed over shallower ones.

July 26, 2021 – We have just reviewed a number of new aero bike wheelsets including the Zipp 454 NSW and Zipp 404 Firecrest, and are currently testing others including the Bontrager Aeolus RSL 62 that are not yet included in this review. I will update the review when all of that is done. The reviews below are still valid but haven’t been rated against the wheelsets we’ve recently reviewed or those we’re testing now. Thanks for your patience.

I recommend both the ENVE SES 5.6 disc and rim brake models as they excel on nearly every measure. They are available at the best prices from stores I rate highly for US/CA readers here and here, and for readers in the UK, EU, and other countries here and here.  I also recommend the Bontrager Aeolus XXX 6, available here, as the best set of dedicated aero bike wheels for disc brake bikes, and the ENVE 65, available here and here, as the best value aero disc wheelset.

Aero bike wheels look fast, ride fast, and race fast. At 55mm to 65mm deep, they are the racing bike wheels of choice for most flat and rolling road races including crits, and can also work as triathlon wheels if you want one set for multiple racing events.

For those of us who don’t race but want to go our fastest in training and on competitive group rides, the best aero wheels can give you that extra aerodynamic performance when it’s your turn to pull or sprint for the town line yet can still provide the stiffness, handling, and comfort you’ll find in all-around wheels 10-20mm shallower.

In this post, I review and compare some of the best aero bike wheels available today and say more about why riders and racers should consider them.

Related: Looking for all-around carbon wheels for your road disc bike?  Click Best Carbon Disc Wheelset

Related: Not sure what kind of wheels to get?  Click Road Bike Wheels – How To Choose The Best For You


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Unlike weight, aerodynamics almost always matters

Best Performer ENVE SES 5.6 disc and rim brake aero wheelsets are also great all-arounders

Bontrager Aeolus XXX 6 road disc wheels are the Best Perfomer among dedicated aero bike wheels

See ratings and reviews of the best aero disc brake wheels

See ratings and reviews of the best aero rim brake wheels

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The world that most cyclists know is flat. Pancake flat for the most part and even flatter than an IHOP pancake in the case of a half-dozen US states according to researchers. Unless you live in or near the foothills of the Rockies, Sierra Nevada or the Appalachian Mountains, those of us who ride in the United States and Canada are going to be on pretty flat roads most of the time with no more than an occasional and short hill that exceeds a 5% grade.

And despite the wonders of the Alps and other mountain ranges featured in the summer pro stage races, Europe is mostly flat too. The European Plain, which runs from the Pyrenees along the Spanish and French border all the way to the Ural Mountains in Russia “gives Europe the lowest average elevation of any continent” according to no less an authority than the Encyclopedia Britannica.

Australia, New Zealand, and the South Pacific? Pretty much flat, flat and flat. The Sydney Morning Herald reported that “after more than four years” work, the final topographic maps, covering Australia, New Zealand and more than 1000 Pacific, Indian, and Atlantic Ocean islands” developed from radar data taken by the space shuttle showed that “Australia was the flattest continent in the world.”

As for the mountains, I’m told by some well-placed elves that only 12% of the world’s population actually lives there.

So why do so many of us look to buy (and read my post recommending) climbing wheels? Perhaps it’s because many of the most famous cyclists going back to icons Eddy Merckx and Fausto Coppi to the modern-day heroes like Egon Bernal and Chris Froome conquered the cycling world while climbing mountains.

And why do we focus so much on wheelset weight when choosing between them? Perhaps because weight is one of the most quantifiable differences between wheels. Yet for most riders, reducing our own body weight by 2.5kg or 5lbs would save us a whole lot more in both road time and pocket change than replacing our stock wheels with a good set of climbing ones.

If you are a serious regular cyclist or what I call a road cycling enthusiast (see here for definition), you need to focus on aerodynamics and aero wheels, two things that are critical to cycling fast on the mostly flat earth we ride.

Weight only matters when you are accelerating and when you are going up steep hills and climbs beyond 7% or 8%. But, as explained above, the weight that matters most is your body weight and how much power you can crank out relative to your weight. Your bike and wheelset weight have little relative effect when accelerating and climbing until you are super fit, well trained, and looking for incremental gains.

Unlike weight, your aerodynamics almost always matters except when you are drafting off of someone in front of you or slowly going up steep grades. And the faster you go, the more it matters. Aerodynamics even matters more than weight when you are accelerating, though the measured difference between the two is marginal.

If you regularly average about 20mph/32kph and faster on your rides, aerodynamics matters a lot and can save you minutes on a 50 mile/80K ride based on how you position yourself on your bike and what gear (wheels, frame, tires) and kit (helmet, jersey, etc.) you use.

If you are averaging anywhere near 25mph or 40kph on your road rides and races, you are leaving a lot of time on the clock and drag on the road if you aren’t locked into what better aerodynamics can be doing to save you time and power.

The chart below summarizes this; the posts on training and technique (here) and gear and kit (here) go into more detail on how to go faster including the role of aerodynamics.

Aero bike wheels

So if you want to go faster, an aero wheelset is part of what will make it happen.

But aren’t aero bike wheels just for time trialists and triathletes, those poor fools that bend over with their hands out in aero bars for miles at a time, not having to worry about making any sharp turns, with no other riders near them to maneuver around, and going so ridiculously fast that those freakishly deep rims they ride on really make a difference?

Yes, deep aero wheels are certainly for those riders. They will be on a 60-65mm deep front wheel and an 80mm deep or completely covered disc wheel in the rear. But aero bike wheels, those in the 55mm to 65mm range are also road racing bike wheels and regular riding wheels for fast roadies riding on flat and rolling terrain. Some can also climb.

In 2010 Zipp introduced the 404 Firecrest carbon clincher, a product that changed the direction of high-performance wheelsets of all depths. The Firecrest rim had a rounded “nose” where the spokes attached to the rim and toroid-shaped rim sides. This profile differed greatly from those pointy-nosed, V-shaped ones that deeper rims had at that time. It was also several millimeters wider at the brake track than most other wheels and was 58mm deep.

Testing showed the Firecrest had less aerodynamic drag than wheels much deeper and weren’t buffeted by side winds the way even shallower wheels were. As a bonus, you could actually slow these carbon-rimmed wheels down without growing old waiting for it to happen and losing your hearing from all the screeching coming from the braking action.

The Firecrest wheels set a new standard for rim and wheel design.

Most of the leading wheelset companies followed with carbon clincher wheels that emulated the Firecrest 404 shape and depth. Many also introduced triathlon wheels in the 70mm+ range to compete with the Zipp 808 Firecrest for the speed-demon, TT and triathlon riders. Another group of shallower, 30-45mm deep carbon clinchers also came out for “all-around” riding and climbing led by the Zipp Firecrest 303 and later the 202.

In the last several years, more and more 55-65mm deep, carbon-clincher wheelsets with “blunt” noses and either toroid or U-shaped rims with 17mm, 19mm, and even 21mm internal widths and 26mm to 30mm external widths have been introduced for both rim brake or road disc bikes. Tests show these aero bike wheels are nearly as fast as the very deepest triathlon wheels.

The best of these don’t get pushed around by crosswinds, are stiff and comfortable, handle well, and are faster yet nearly as responsive and light as carbon all-arounds that are 10mm to 20mm shallower. They compare well or better against many of the same performance criteria that I find matter when choosing wheels (see here).

Below, I share with you the conclusions I and my fellow evaluators reached after riding many of the best aero wheelsets you can use as racing bike wheels or for riding fast without needing to race. At the end, I also list the aero bike wheels we haven’t reviewed and why. 

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Disc brake Aero Wheelsets

Best Performer


For a wheelset that was first introduced in 2016, the ENVE 5.6 disc still stands apart from the competition.

It’s not just the design characteristics that make it distinct, most notably the different front and rear rim depths, widths, and shapes. Rather, it’s the performance the design attempts to deliver that separates this wheelset on the road from others in the aero wheelset category with rims that go 55-65mm deep.

Conventional thinking about wheelsets (or at least the way I’ve always thought about them) is that there are low profile wheels, all-around wheels, aero wheels, and deep aero wheels.

All-around wheels, as the name suggests, should do a bit of everything. While not optimized for any single type of riding, the best are light enough for climbing, aero enough for fast riding, and stiff enough for quick acceleration. They are typically the best choice when you’ll be in the saddle for hours at a time riding a mix of flats, rollers, and climbs. Nimble, precise handling is a hallmark of all-around wheels and crosswinds are either not an issue or easily managed.

Conversely, aero wheels have typically been those we road cycling enthusiasts want when riding and maintaining speeds in the mid 20mph range (high 30kph range) is our priority above all else. While dedicated time trialists and triathletes might ride an 80mm or so deep aero wheelset or rear wheel, roadies go for 55-65mm aero wheels when most of what we ride is flat, straight, doesn’t involve a lot of big speed changes or accelerations, and lasts for no more than a couple of hours.

Good handling is a bonus for aero wheels. Since the rides are relatively short, comfort is nice but not a priority. Crosswinds and climbs are to be avoided.

ENVE 5.6 disc

Unique in our experience testing aero wheels, the ENVE 5.6 disc (and 5.6 rim brake model) rides almost like a blend of the best performance characteristics of wheelsets in both the all-around and aero categories. The parallel that comes to mind is what’s happening more recently with bikes that are combining an aero bike’s speed, road racing bike’s responsiveness, climbing bike’s weight, and endurance bike’s comfort into one bike that delivers all of that performance.

This ENVE 5.6 disc is as stiff as the best of the road disc wheels we’ve tested in the aero or all-around wheelset categories. Its responsiveness and acceleration are unmatched by most others in the aero test group and on par with the best in the all-around field.

While most aero wheels demand the kind of effort that convinces you to bring them up to speed gradually, you can sprint up these snappy ENVE 5.6 discs without feeling like you are burning through your limited number of matches.

These wheels also climb like champs, a level above other aero wheelsets we’ve reviewed and on par with the best all-around ones. Nate, my fellow tester with serious climbing palmares, noted this strength. Road racing tester Miles took it a step further saying they turned his Giant Propel aero bike into a capable climbing one going up a long, New Hampshire ascent that topped out at 14%.

ENVE 5.6 Disc

Miles’ aero bike rides like a climbing one going up steep hills with the ENVE 5.6 disc wheels

The ENVE 5.6 disc handles as well as any of the aero wheels we’ve tested. Miles railed corners at high speeds with them and said he could often put in gaps to other riders during turns. He was also “totally confident diving these wheels into hairpin downhill turns.”

Though these wheels are easy to bring up to speed, holding that speed is one of the few places they are average compared to their deeper, heavier aero wheelset competitors.

Crosswinds are not an issue for the ENVE 5.6 disc. Their comfort is better than most, making 3-hour rides easy assuming your fitness also supports that long and fast a ride.

For those of us who take a close look at specs, this wheelset’s actual weight (1576g) stands out against other aero wheels with all but the Reynolds Aero65 DB (1611g) measuring between 75 and over 200 grams more. But, the Reynolds rims alone weigh 100 grams more than those on these ENVEs.

While the ENVE 5.6’s lighter weight may help you on climbs, that along with a 3-10mm shallower front wheel than others in the aero category may owe to its more average ability to maintain your speed. It’s not subpar but it’s also not up there with the best.

The finish on this wheelset and most ENVE wheels I’ve tested is a little disappointing. ENVE doesn’t use paint in their rims and the powdered curing agent they use in the resin can pool in spots near the surface of the rim during the molding process. When this happens, you’ll see some white markings when looking closely, typically along the spoke edge. They can become more pronounced over time.

It’s never been a big enough issue that I wouldn’t recommend ENVE wheels and I wouldn’t think it has any effect on their performance. ENVE replaced one set of wheels I bought where I thought the marks were particularly pronounced and they handled it professionally.

We tested the 5.6 disc with ENVE’s alloy hub, one that uses Mavic’s Instant Drive 360 internals. It’s a similar ratchet design to the DT Swiss 240 hub and engages well, spins smoothly, freehubs with a moderate amount of noise, requires next to no maintenance, and at $2550, is the lowest-priced option. ENVE also offers these wheels with Chris King R45 alloy and ceramic bearing hubs or I9 Torch ones, all of which make the wheelset marginally heavier and significantly more expensive than with the ENVE hub.

If you’re looking for a wheelset to help you in time trials, flat crits, or flat solo and group rides, a more traditional design aero wheelset may be better for you. But if you are an enthusiast who wants to ride fast all day, spinning up quickly from a variety of speeds, on all grades of terrain, handling precisely through corners and switchbacks, the ENVE 5.6 disc stands alone in being able to do all of that.

You can find the ENVE 5.6 disc, or more properly the ENVE SES 5.6 Disc Carbon Fiber Wheelset through these links to the wheelset’s page at my recommended stores Competitive Cyclist and Tweeks Cycles. It’s also available here from the ENVE website.

Best Performer


The Bontrager Aeolus XXX 6 Disc wheelset sets a great example of what dedicated aero disc wheels should be.

It accelerates up to speed well on the flats and maintains your momentum with the best in this 55-65mm deep wheelset range. With its VU rim profile, narrow at the spoke bed but soon widening and maintaining parallel rim walls, crosswind management is good.

No doubt, the Aeolus XXX 6 is a stiff and responsive wheelset that seems to deliver to the road whatever you put into the pedals. But it isn’t overly stiff to the point that you get exhausted after a couple of hours of hard riding.

Indeed, Nate, Miles, and I found the wheelset comfortable enough for 3+ hour-long rides with 26c Bontrager R3 tubeless tires mounted and inflated at 65 to 70psi in the 21C rims. Inflated to a racer-hard level 10psi higher or more for our 155lb +/- bodies quickly reduces this wheelset’s compliance and road feel and borders on harsh.

For its 60mm deep wheelset, the Bontrager XXX 6 disc wheels handle well and give you plenty of confidence when cornering or riding fast in a small, coronavirus household-sized group (of riders you don’t actually live with).

Perhaps I could have serviced the hubs a bit to loosen the seals and lubricate the rear freehub. The latter seemed louder than most DT Swiss 240 hubs we remembered riding and the former remained tight even after many miles of riding. While a freehub’s sound can appeal to your personal preference or not, we all agreed the engagement was adequate and average amongst the group of road disc aero wheelsets we tested.

On short, shallow climbs, the momentum the XXX 6 brings into the climb helps propel these wheel. You can also raise the speed on a 5% or smaller grade without too much trouble. Beyond that pitch however, you have to put in a good deal more work to keep them going.

We rode this wheelset with Bontrager’s plastic tubeless strips Bontrager ships with to install into the rim bed. With those, the XXX 6 weighed in at 1710 grams on my scales, in line with an aero wheelset. Added weight benefits your ability to maintain your momentum once you reach aero speeds.

If you prefer to ride them with clincher tires, Bontrager also provides cloth strips that drop the weight by about 85 grams. I’ve also set up Aeolus wheels with tubeless tape, good for either tubeless or clincher tires, that would bring the weight of the XXX 6 down to about 1610 grams and likely give you a bit more responsiveness and easier time going up rollers and steeper pitches.

Looking across all the performance considerations, there’s little the Aeolus XXX 6 doesn’t do well and fast on flat and mildly rolling terrain. Add to that its glossy finish and distinctive graphics and you’ll get quite a boost to your cycling experience with these wheels.

You can get them directly from this page at the Trek online store.

Best Value


If you’re not all-in on aero but want some aero benefits, the ENVE 65 wheelset provides a solid foundation for aero riding without making a maximal investment. For that reason, I recommend it as the Best Value for disc brake aero wheelsets.

What is all in? Aero frame, aero components, aero kit, 23-25mph/37-40kph, TT and crit racers, where every bike length matters.

What is want some aero benefits? Race bike, aero aware, 20mph/32kph and up, fast group rides, occasional races, where going fast on flats and gently rolling terrain matters.

Most aero wheelsets, the ENVE SES 5.6 disc and rim brake wheels being an exception, aren’t versatile enough to ride on all terrain. But on the right terrain and in the right riding situations, the best aero wheels make a decisive speed difference when compared to shallower, all-around ones.

ENVE 65 aero wheelsIf you want the benefits of the best aero wheelset performance but can’t quite justify the investment, the ENVE 65 will get you close and for a lot less. At $1600/£1850/2120 for the ENVE 65, that’s $800/£150/280 to $1000/£950/1020 less than my best-rated aero road disc wheelset performers.

The ENVE 65 is as stiff and compliant as the best. That’s a great combination to have in any wheelset, one that other aero and all-around wheelsets I’ve ridden priced in the same range as the ENVE 65 almost never pull off.

Aero performance is, obviously, the critically important measure of an aero wheelset. While we can’t test them in a wind tunnel, I and my fellow testers Nate and Miles can and have judged and compared several indicators of aero performance across the range of wheelsets we’ve ridden. And on those indicators, The ENVE 65 is on par with the average higher-priced aero wheelset though slightly off the pace of the best.

Specifically, the ENVE 65 holds its momentum well once at aero speeds though not as well as the Bontrager Aeolus XXX 6, Reynolds Blacklabel Aero 65DB or Roval CLX 64. It also holds its own or, perhaps better said, holds you reasonably close to your line in crosswinds, something that most >$2000 wheelsets do these days and just the aero wheelset category’s Best Performers ENVE 5.6 and Bontrager Aeolus XXX 6 do better in our experience.

The ENVE 65’s 28.3mm outside rim width meets or exceeds the rule of 105 rim to tire width ratio per my measurements with the ENVE hookless rim compatible and approved/recommended 25mm Schwalbe Pro One TLE, Hutchinson Fusion 5 Performance 11Storm, and 26mm Specialized S-Works Turbo RapidAir tubeless tires.

Acceleration, handling, and climbing performance are on par with the average aero disc wheelset in this review but off the pace of the best performers. Whether those performance differences would be noticeable in a flat to rolling TT or crit is debatable. They would if you were to take them on hillier terrain or races with more demanding cornering.

As with the ENVE SES 5.6 option we tested, the 65 uses the same ENVE Alloy hub internals. They engage and roll very well on the road and emit a low-frequency, hollow sound. The 65 uses the Foundation hub shell, only 6 grams heavier than the one on the 5.6 which is milled in such a way to allow for its paired spoke lacing. You can also order the ENVE 65 with a distinctively louder Industry Nine hub if that’s your preference.

So how do the aero category’s Best Performers ENVE 5.6 and Bontrager XXX 6 differ from the Best Value ENVE 65 and is that performance enough to justify the price difference?

The ENVE 5.6 is more responsive and versatile, a better handler, and less affected by the crosswinds. I can ride the 5.6 confidently as a very fast, everyday wheelset on any combination of flats, rollers, and climbs either riding solo or in a collegially competitive group ride. Fellow testers Miles and Nate would choose the 5.6 ahead of the rest for a road race on anything with a sustained 7%+ grade hill or three in the course profile.

While it takes longer up to speed, the ENVE 65 is a touch faster at full throttle than the 5.6 and would be the better choice for a flattish solo outing, bullet train group ride, or sprint finish race. Its wider internal, hookless rims, more basic layup, and standard spoke lacing might be what makes it a bit more compliant if less snappy than the 5.6 at the same tire pressure.

Though not as refined, the ENVE 65 has a more similar performance feel to the Bontrager Aeolus XXX 6 than ENVE 5.6. The XXX 6 is faster, quicker, handles better, and is less moved by the crosswinds. But the 65 and XXX6 are both focused on raw speed, are best on the flatter rides and crit races with only small or short rollers.

The choice is up to your aero performance id and cycling budget ego to resolve.

You can order the ENVE 65 wheelset at my top-rated stores using these links to Competitive Cyclist in the US and Canada and Merlin in the UK, EU, and elsewhere.


If you are looking at aero wheels like the Reynolds Blacklabel Aero 65 DB, you should be all about going fast. You likely race and may even live to do so. But you certainly have speed as your top priority and there’s nothing else in your top 5.

You’re probably doing the whole aero thing – an aero bike, aero position, aero road helmet, racing kit, shaved legs, etc., etc. You don’t much care about things that don’t matter when it’s all about going fast for you. Things like comfort, climbing, even the occasional crosswind are distractions at best.

If that doesn’t describe what you are looking for, you’re in the wrong aisle (or wrong review).

If it does, come a little closer and let me tell you about this Blacklabel Aero 65 DB wheelset from Reynolds.

Reynolds Aero 65 DB

Bottom line, this is a stiff, fast wheelset. My fellow tester Miles, a P/1/2 crit and road racer who finishes top 10 in his age group at the US Masters Nationals reported that “once in a full sprint, these wheels just simply fly.”

Riding the Aero 65 DB wheelset enabled him to snap a bunch of sprint-oriented Strava KOMs and make his Giant Propel Advanced SL Disc go about as fast as he thinks it can.

Speed comes from a stiff wheelset that responds when you tell it to go with rims that cut through the air on smooth-rolling hubs. That’s the make-up of this wheelset.

The Blacklabel Aero 65 DB uses i9 hubs. They’re louder than most but engage quickly and roll easily. The rims have a V-shaped profile with internal spoke nipples that trades-off crosswind performance and easy spoke tensioning adjustment for straight-ahead lift.

Remember, it’s about the speed with this wheelset. If loud hubs and the need to keep both hands on the bars in the crosswinds isn’t for you, neither are these wheels. They also aren’t the most comfortable wheels at the 75-80psi that Miles rode them at or the 60psi that I did on Continental Grand Prix 5000 TL tires that mounted easily but took a few iterations to seal and hold air.

For these Reynolds wheels, it’s not just about going fast in a sprint or straight line. Both Miles and I experienced the momentum the Aero 65 DB gave us to quickly punch the kind of 100 meter climbs up to about 10% you’ll often find on circuit races. We were also impressed with how well their aerodynamics assisted on extended climbs up to a 5% grade.

Oh, and they corner very well at speed too. While crits and road races are only a dream in the age of Coronavirus when we tested these wheels, Miles reported he “was able to confidently whip through some corners at around 30mph” in his non-race testing.

I don’t often ride that fast even on a straight but, when I do, I felt the sensation of gliding along at such pace and with such ease that I could block out the stresses of life around me.

If you’re all about going fast and doing crits and rolling road races and time trials – and everything else be damned – you should consider the Reynolds Blacklabel Aero 65 DB. At USD$2100, it is also competitively priced among others in the aero wheelset category.

You can get it through this link to Competitive Cyclist, one of my top-ranked stores and at others I recommend for their low prices and high customer satisfaction ratings by clicking on this pre-sorted link to Knows Shop.


Speed is clearly the calling card of the Roval CLX 64 wheelset. It’s one of the fastest aero disc wheelsets we’ve tested and one of the easiest to maintain its speed.

Fellow tester Miles sensed that immediately and went KOM hunting, bagging three highly competitive ones with the CLX. He only wished he could have put them work on a crit course or rolling circuit race where he felt they would be ideal. Alas, covid wiped out those opportunities and much else this year.

Nate also tested these wheels extensively as they came with the Specialized Venge he bought this spring. Always in search of the best setup, he rode them with both Specialized’s 26C Turbo Cotton clincher tires at 85psi and 65psi and 26C Turbo RapidAir tubeless tires at 85psi, 72psi, and 60psi.

For Nate’s bike and body weight, the tire calculators suggest a front tire pressure of 68-69psi and rear tire at 72-74 psi with the tubeless tire inflation at the lower end of this range. Doing some of his own speed testing, he actually found 85psi front and rear to be the fastest on both the clincher and tubeless tires.

Miles, a few pounds lighter than Nate and also riding an aero bike (Giant Propel Advanced), had his best speed with the Cottons at 65/70psi front/rear and the RapidAirs at 60/65psi. This is just another example of the value of finding the right pressure for you.

Both found the pressures that gave them the best speed also gave them the best comfort and road feel.

Unfortunately, both also reported the CLX 64 slow to get up to speed compared to other aero disc wheelsets we tested. Stiffness was only average and with both the XDR rear hub driver on Nate’s bike and Shimano one Miles used, the DT star ratchet was slow to engage.

Climbing was also a mixed bag. Coming off the flats into short rollers, these Rovals flew. But for longer pitches below 6% and anything steeper, the CLX 64 struggled.

Handling was a bright spot on the Turbo Cottons but only average on the RapidAir. We tested all the other aero disc wheels in this review on tubeless tires and several performed exceptionally well, clearly better than the Rovals. Mind you, the Roval CLX 64 handle confidently and well overall but just not to the level of those we rated higher.

With the widest rims among those we tested (approximately 30mm external, 21mm internal), most any 25C or 26C tires and narrower 28C ones including Specialized’s S-Works Turbo RapidAir will give you a rim to tire ratio well above the 105% where you’ll find your best performance. You can check out our review of the best tubeless tires for the details.

Not surprisingly, our take of the comfort of the CLX 64 varied somewhat based on tire and pressure choices. While all of us found the wheels very comfortable on the super-supple Turbo Cotton, that’s not a tire you’ll want to ride every day as its puncture resistance scores quite low on independent tests.

On the Turbo RapidAir at the 60-65psi range Miles and I rode them, they were comfortable enough for a day-long ride. Nate actually found them more comfortable at his preferred 85psi than at the lower pressures he tried but even there, didn’t experience the same level of comfort as the other wheels tested for this review.

Our performance score sheet shows pluses and minuses for the Roval CLX 64 disc wheelset and many more that are on par with others we tested. If what matters most to you puts these aero bike wheels in the win column, you can order them through this link to JensonUSA.


Best Performer

ENVE SES 5.6 – A snappy wheelset that excels in nearly every measure

ENVE introduced the SES 5.6 in 2018 as the successor to the SES 4.5. When I last reviewed this category of aero bike wheels, I picked the SES 4.5 as the best performer. After comparing the wheels in the category this time, the SES 5.6 is the one I’d choose to ride on.

No, I don’t have an ENVE tattoo anywhere on my body. And sadly, I returned this wheelset just like every other that is sent to us to demo for reviews.

In fact, among all the wheelsets I rode this past season, I enjoyed riding the ENVE SES 5.6 more than any other one. While my riding profile would normally suit a shallower wheelset, I’d happily ride this one most any day of the week.

The SES 5.6 is more responsive than any other wheelset I’ve ridden including shallower and lighter ones. It jumped forward when I wanted to move out or ramp up my speed while underway. When I cranked up the watts going up rollers and steeper hills or working to close a gap, it was stiff. And it handled precisely and confidently going fast downhill and into corners.

ENVE SES 5.6 Aero bike wheelsThis ENVE wheelset seemed to take less effort to go fast and held my speed incredibly well. I didn’t measure watts vs. mph but it sure felt like I was putting out less of the former and getting more of the later than any other wheelset I can remember. You know when you feel like you are going fast but not working that hard? You look down at your speed and say to yourself… whoa, I’m going fast. It felt like that a lot on these wheels.

The Chris King hubs on the SES 5.6 rolled very smoothly. The wheelset was comfortable on their tubeless rims with  20mm inner widths. I also felt confident braking on the textured rim brake tracks that emitted a slightly higher frequency and lower volume than Zipp’s textured ones.

On a fall day full of crosswind, the ENVE SES 5.6 compared favorably against the Bontrager XXX 6 and Zipp 404 NSW that I rode back to back to back. And the Bonty and Zipp were amongst the best I’ve ridden in crosswinds in this racing bike wheels category.

So that’s my take. For context, I’m a B-group, 18-20mph enthusiast on an endurance frame. I don’t race or time trial but I do try to ride fast.

Nate is my evil twin tester. While we weigh practically the same (150-155lbs – that’s the twin part), he’s an A-group ride leader, does road races, hill climb events, and even the occasional TT. He wins some of them in a pretty tough age group. And he has a stiff Specialized S-Works Tarmac racing frame.

He’s also a very, very nice guy but truly evil if you try to outdo him on the road.

Nate and I reached similar conclusions about the SES 5.6 on some criteria and different ones on others. He really liked how they performed at high speed and how well they maintained their momentum once there. “Wheeeee!!!” was the technical term he used to sum up his aero evaluation.

He also liked how they accelerated from a stop or when he wanted to make a big power burst while already at speed. They were noticeably tougher to climb with than the 40mm-50mm carbon wheels he normally rides but he found this to be true of many of the wheels in this racing bike wheels category. That was my experience too.

For the record, the wheelset we rode had Chris King R45 hubs and came in at 1559 grams on my scale, the same as what ENVE claims for them. The front wheel was 5g lighter and the back 5g heavier than what ENVE claimed but obviously, well within the margin of error and manufacturing tolerance.

If you think riding a 1481 gram wheelset will help you climb better, you can save those 78 grams (and get a quieter freehub too) by going with the ENVE carbon shell hub on these wheels for the same $3000 price as the one we rode with the King. Alternatively, if you prefer spending $2550 for the wheelset, you can spec it with the ENVE alloy shell hub at 1593 grams.

Nate didn’t love the SES 5.6’s ride and handling. At least, he didn’t love it compared to the equally stiff Bontrager Aeolus XXX 6 or the more forgiving Zipp 404 NSW.

Using the Goldilocks testing method on all three wheelsets, he found ENVE wheelset rode too hard at 80 psi, was less accurate at 65 psi, but at 72 psi offered the best combination of comfort and handling. (FYI, I rode it at 60 psi, closer to where ENVE suggests riders that weigh what Nate and I should).

While Nate found the ENVE and Bonty equally responsive at 72 psi, to him the ENVE seemed to exaggerate the roughness of the road at that pressure while the Bontrager and Zipp wheels dampened it.

In the crosswinds, Nate felt ENVE and Bonty were better than the Zipp.

Nate summarized his evaluation of the SES 5.6 using the practical framework of ride time and road terrain.

“Over shorter rides (<3 hours) without too much elevation or on smoother roads, I’d take them in a heartbeat…there are some KOMs I’ve been needing to claim back and these might just be the right tool :-). However for longer rides and certainly on my stiffer bike frame, I think I’d rather have the smoother Zipp/Bonti ride, even if sacrificing some of ENVE’s responsive snap.”

So bro, I guess we come out at much the same place?

I would summarize it this way: The ENVE will make an already comfortable endurance bike ride stiffer and more responsive while the Bontrager will make a stiff bike ride more comfortably.

You can click on these links to top-ranked stores Competitive Cyclist or this link to Know’s Shop to find and order the ENVE SES 5.6 rim brake wheelsets at the best prices from stores I recommend. You can also get it directly from ENVE.

Bontrager Aeolus XXX 6 – High-performance aero cruiser lacking responsiveness

Getting great stiffness and comfort in one wheelset is a tough combination to pull off. When you do, you can deliver many additional performance benefits as by-products. Bontrager’s Aeolus XXX 6 makes this happen unlike any other set of aero bike wheels we’ve reviewed.

The first thing you notice about the Aeolus XXX 6 is just how comfortable it feels. It rolls beautifully and sucks up rough roads and imperfections so well it seems like you are riding on a far better surface than the one your eyes tell your brain you are.

Nate called it “amazing” and commented that he could feel the difference in comfort within a couple of hundred yards of leaving his house.

Don, a member of our gear testing team who does Ironmans and half triathlons, also noted how much better the XXX 6 was at absorbing rough road conditions than other wheels he’s ridden.

At 21mm internal width, this and all the Bontrager Aeolus XXX models are some of the widest of any of the rim brake wheels intended primarily for paved roads. But don’t jump to performance conclusions based on its specs.

The ENVE 5.6 at 20mm internal rim width and also run tubeless on the same tires and at the same pressures during our test rides didn’t provide the same level of comfort. Only the Zipp 404 NSW at 19mm and run tubeless matches the comfort of the XXX 6 among these aero wheels.

But, hey, if you are a racer or speedy roadie, comfort is nice but it’s not why you ride. You want to go fast. And while a comfortable wheelset may make it seem that you aren’t going as fast as you are, on these Bontrager wheels, you are also going fast.

Let me say that again. You are going fast when you ride these Bontragers.


Bontrager Aeolus XXX 6 Aero bike wheelsThe stiffness of this wheelset certainly helps create speed. Riding the XXX 6, it feels like there is no slack between your pedals and the road. Your power transfers directly. The handling is also precise, making you faster in corners. It all feels very tight, like a good horn section in a well-practiced band. (Tower of Power anyone?)

An independently run and ongoing aero drag test done by Hambini Performance Engineering has to date compared 45 wheelsets of different depths from a range of brands. One of its key findings is that wheelsets of the same depth essentially have the same aero performance. The Bontrager Aeolus XXX 6 and XXX 4 wheelsets, however, have shown to be a notable exception that perhaps proves the rule that this finding suggests. Their aero performance was on par with wheelsets 20mm deeper.

There’s been a fair amount of pushback from some wheel designers and cycling industry leaders about Hambini’s testing protocol. It uses the transient drag methodology adopted by the aerospace industry rather than the static one employed by most in the cycling industry.

From my humble understanding of cycling aerodynamics and my experience riding a lot of wheelsets, I saw some things that I really liked about the testing – its independence, seemingly more real-world conditions, and the sheer number of models it compares.

There were also some things about it that didn’t seem to sit well. The test used the same width tire regardless of the rim width. This seemed at odds with all I’ve learned about the aero benefits of keeping the mounted and inflated tire no wider than 95% of the rim so the air coming off the tire would stick to the rim rather than separate from it.

Was it possible that a wheelset with a wider rim like the XXX 6 performed better than one with a narrower one (as most were) because the tire width allowed the air to stick to the Aeolus longer?

Regardless, refer back to what I wrote above. You go fast when you ride these Bontragers.

Hambini also concluded that wheels of the same depth all felt the same amount of crosswind force regardless of their profile. Anecdotally, I’ve never found this to be the case when comparing different wheels. Wheel designers creating new deep rim profiles have done a lot of work over the years to reduce the effect of crosswinds by moving from box- and V-shaped rims to “toroid” or 0-shaped and U-shaped rim profiles with rounded and “blunt” noses.

On different windy days, Nate and I ran back-to-back crosswind testing of the Bontrager Aeolus XXX 6, ENVE SES 5.6, and Zipp SES 4.5 NSW. I found the Bontrager managed those crosswinds noticeably worse than the other two wheelsets. Nate found the Bontrager on par with the ENVE with the Zipp lagging. Not conclusive.

One thing Nate, Don, and I did agree on was Bontrager’s superior braking abilities. Because the wheelset is stiff, you can position the pads closer to the rims on this aero wheelset than on others. That also gives you better modulation right off the bat.

Second, the braking is quieter than those like the ENVE and Zipp which have aggressively textured tracks. And third, there isn’t much drop off in the Aeolus’ braking performance between dry and wet roads the way there often is on other carbon rim wheels that smooth brake tracks as the Aeolus does.

On the downside, the three of us also agreed that the Aeolus XXX 6’s acceleration and climbing left a lot to be desired. They were a far way off the snappy ENVE SES 5.6 and underperformed three of the other wheelsets we tested in this category.

As aero wheels that are often used as racing bike wheels, was this weakness less important than some of the Aeolus’ strengths?

Don, our triathlon cyclist called them “sluggish” on hills and noted there aren’t many tris he rides that are flat enough that he wouldn’t notice this. Nate, our road racer and climber extraordinaire said they “weren’t great” going uphill.

I wrote the word “lethargic” down in my log after riding them for a couple of weeks. They were great once I got them going but my B-group power took a while for that to happen. I couldn’t get them to accelerate like others I’d been riding and I really struggled on them going up 5% grades.

Maybe I was fatigued or had been riding too much before I started testing the XXX 6? When I did the back-to-back-to-back crosswind testing, however, I confirmed the lethargy I felt from the Bontragers compared to the highly responsive ENVEs and Zipp 404 NSW whose responsiveness I rated average against all the wheels I tested in this category. Seeing Don’s and Nate’s notes was further confirmation.

The weight of these Bontragers, which I measured at 1669 grams with the tubeless rim strips installed, is 110 grams heavier than the ENVE and nearly 50 grams heavier than the Zipp both also taped up for tubeless tires. That amount isn’t enough to explain the different acceleration and climbing different we felt.

Note that Bontrager claims the XXX 6 weight at 1530g, 140g lighter than I measured it. Bontrager uses plastic rim strips to set the Aeolus wheels up tubeless and they do add this much weight. If you prefer to run them with a tube and tire, you can remove the rim strip and use regular tape.

The Aeolus XXX 6 is a speedy, stiff, comfortable cruiser that handles and brakes as well as any in this category of racing bike wheels. It’s likely best suited for riding and triathlon racing on flatter terrain than for road racing and crits which require quick accelerations or riding rolling or hillier terrain.

If those strengths match your riding or racing profile, you can buy a set up the Aeolus XXX 6 wheelset direct using this link to Bontrager. For UK and EU readers.

Zipp 404 NSW – Fast and comfortable but stiffness disadvantages it against the best

The original Zipp 808 and 404 Firecrest wheels helped define the aero bike wheels category. The 404 Firecrest were among the first carbon racing bike wheels used in professional road races. Many pro and amateur racers also used the nearly 60mm deep 404 as a front wheel paired up with the 82mm deep 808 as a rear for time trials and triathlons. As more road riders took to triathlons, they used the 404 Firecrest wheelset for that event in addition to doing road races, group rides, and training.

Yes, the 404 Firecrest wheels were expensive but you only had to buy one wheelset to be fast across a range of riding profiles.

At just the time that carbon wheels, clinchers, aerodynamics, triathlons, and road racing became more popular, Zipp had set a performance bar. Zipp expanded the Firecrest line to the shallower 303 and 202 based on the same rim profiles and other design and ride characteristics that had made the 404 Firecrest so successful.

Other wheelset companies took note of what Zipp and HED, which shared the original patent for the toroid-shaped rim profile that led to fast wheels and applied it exclusively to tubular models, had done. Carbon clinchers with wider, rounder shapes became a very competitive market with established and new players competing with the design and aero performance levels that Zipp and HED started.

While Zipp went through a succession of different hub designs to make the Firecrest wheels more durable and improve their stiffness, the NSW was the brand’s first new rim design and replaced the Firecrest as Zipp’s new top-of-the-line wheelsets in 2017. This was roughly 8 years after the 404 and 808 Firecrest went into production.

Zipp introduced a second-generation NSW in 2018 and made the 2017 NSW rim the heart of its new Firecrest line, selling it for about $1000 less than the NSW.

While only a year apart, Zipp made major changes to the rim used in the 2018 404 NSW. While the same depth, the shape changed, its internal width increased 2mm to 19mm, it became part of Zipp’s first tubeless family of wheelsets and was offered in both rim and disc brake versions.  The hubs that were entirely new for the 2017 NSW were retained for 2018s.

So a lot has changed in a short time. The brand name is the same but there is little about the performance of the 404 Firecrest that you might know or have heard about that applies to the performance of the 2018 Zipp 404 NSW wheelset

How do they perform?

The Zipp 404 NSW are fast wheels. Whether it’s the rim profile and width or the smooth rolling and quiet freehubs, both the sensation and reality is that these wheels roll fast underneath you.

While not quite as snappy as the ENVE 5.6, the 404 NSW is a very responsive wheelset that others in this category don’t match. That responsiveness extends to the handling as well. When you want to change direction, the 404 NSW does that very quickly.

They are very compliant rolling over the mix of surfaces you might find on a long ride. Not that you should, but you won’t feel the urge to alter your line or brace yourself for short rough patches you see in the road ahead. Instead, the ride is comfortable, pleasant, joyful, and fast.

The 404 NSWs aren’t as stiff as some of the others in this category and this takes away from some of the benefits of the wheelset as a whole. Responsiveness without stiffness gives you the ability to move out quickly but not the power efficiency to do something about it.  And while you can get in and out of turns quickly, a lack of stiffness brings down the precision or riding-on-rails feeling once in the turn.

As Nate noted in his test rides, these Zipp wheels probably have the best absolute braking power of those we tested in this category. Don added that the brakes were clearly the loudest. I had a similar reaction on both counts in my test rides though I wasn’t bothered by the brake noise.

Despite the 404 NSW’s superior braking force, its inferior stiffness requires you to set the brake pads wider than you need to with the several stiffer wheels in this aero bike wheels category. Otherwise, the rims will rub against the pads as the wheels flex when you get out of the saddle or sprint. With the brake pads opened wider, you diminish the modulation or your ability to feather the brakes to vary the amount of brake force you want to use.

The net result of all this? The NSW’s brakes are less than they could be and don’t match the performance level of the ENVE SES or Bontrager Aeolus wheelsets.

Nate and I were also disappointed with the Zipp 404 NSW’s performance in the crosswind where its shallower 303 NSW sibling performs so admirably. Here again, while not bad and better than some (see the comparative charts), it required more correction than the ENVE 5.6 in separate head-to-head testing we did with several of these wheelsets on windy days.

Knowing the 404 heritage, I probably hold the bar quite high for this newest 404 NSW model. And it performs very well or holds its own against many of the criteria we feel are most important. But others have now passed it in several key areas.

If the 404 NSW’s strengths align well with what you are looking for in a set of racing bike wheels, you can click on this link to recommended stores Competitive Cyclist, Planet Cyclery, Tredz, and others at Know’s Shop to find and order these wheels.

Vision Metron 55 – A good bargain for riding mostly flat terrain

The Vision Metron 55 might be better off changing its name to keep its 55mm rim dimension a bit of a mystery. That’s because it rides differently than the stereotype its depth would suggest. It is a very stiff wheelset and holds its speed like a deeper one would. At the same time, it handles, manages the crosswinds predictably, and accelerates like a shallower set of wheels. Braking is on par with the majority of carbon wheelsets with untreated brake tracks regardless of their depth – fine when the sun shines but a bad bet when it’s wet.

Another irony is the Metron 55’s acceleration, which is pretty good, vs. its weight which not so good. Acceleration can overcome weight with a stiff and responsive wheelset, which this one is. And while I’ve cautioned you, dear fellow enthusiast, not to put much stock in a few grams difference here or there when comparing wheelsets, the rim brake Metron 55’s actual measured weight from three sources I trust comes in at an average of 1705 grams (+/- 20 grams).

This is consistent with my own experience with Metron wheels measuring about 100 grams more than their claimed weight. Note that the disc brake model adds another 110 grams in claimed weight over that of the rim brake Metron 55.

Vision Metron 55 Aero bike wheels

While many wheel makers seem to have scales that somehow calibrate 50 to 100g less than those of riders and reviewers, getting above 1700 grams puts you up in the same class – on a weight standard – with less versatile aero bike wheels that are good for flat riding and triathlons but not for road racing. While most 55-65mm deep wheels are not those you want to climb tall mountains with, you’ll notice 150 grams of difference between wheelsets including these Metrons when you are powering up short, 5% rollers that any all-arounder should cruise up without wondering what they are dragging.

The only other comment I’ll add is that three other reviewers I trust wrote that these same hand-built Metrons came to them out of true. While I’ve not experienced this issue with the Metrons I’ve tested, and it’s certainly one that can be easily fixed, you need to be vigilant when inspecting this wheelset after you first receive it.

Vision wheels are frequently discounted from the prices recommended by the company. You can click on this link to Know’s Shop to find and order the Metron 55 rim and disc brake wheelsets at the best prices from the best stores.

If you ride more flats than rollers, want an all-carbon aero wheelset that’s plenty stiff, and can keep wheels true or have someone who can, the Metron 55 at the right price is worth considering.

Easton EC90 Aero 55 – Stiff and fast but loud braking and poor in the crosswinds

When Easton first introduced the Aero 55 in 2014, the company’s marketing material proclaimed it “the most aerodynamic road wheelset on the market today” and “fastest in all conditions.”  It was quite bold and who knows if it was true, but at least they had the balls to publish their testing protocol and results from wind tunnel tests comparing their Aero 55 tubular and clincher wheels against the Zipp 404 Firecrest, HED Stinger 5 and ENVE 6.7 tubular models.

Zipp, HED, ENVE, and many others have since introduced new aero bike wheels but I’ve seen very few comparative tests published by wheelset companies or industry pubs. The Aero 55 wasn’t included in Bike Radar’s lab test or the independent one conducted by Hambini Performance Engineering. Easton now claims “World Leading Aerodynamics” on the web page for these wheels.

Easton also shared the results of their tests using different model and size tires on these wheels.  Both the wheel and tire test results are published on page 3 of their white paper here.  The tire test results are below.

Easton Fantom Tire Tests on the EC90 Aero 55 Aero bike wheels

What I find most interesting in their data is not necessarily who has the fastest wheels. Rather, the Easton tests show that the time differences between the wheels are about the same as the time differences you get by changing tires. This shows that you can mess up the speed you are trying to gain spending $2000+ on a set of wheels by picking the wrong $150 set of tires, usually by going too wide.

Note that of the ones they test, the 21C, 22C, and 23C tires are the fastest in that order, and they don’t test 25C clincher tires nor do I assume they recommend one if going fast is a priority. Get your comfort from the extra volume in the rims, not the tires, unless speed is less important than comfort, in which case you probably are looking in the wrong aisle for your next wheelset. (I’m talking to you Mr. “I must put a 25C or 28C tire on whatever wheel I ride because that’s what everyone else says I should be doing”.)

I bought a pair of Zipp Tangente 23C clincher tires to use when testing these Easton EC90 Aero 55s. According to the chart, the 21C size of the same model would be a lot faster but I wasn’t sure if I’d ever use a 21C again after evaluating these wheels so budget considerations got the better of me this time. (See, I do it too!) Once mounted and inflated, the 23Cs measured 24.7mm wide on these 19C rims. That’s still over 3mm narrower than the 28.1mm rim width I measured at the brake track. So I was doing my small part to improve the aero performance.

In hindsight, I expect even a 25C size Schwalbe Pro One or Continental Grand Prix 4000S II (the new 5000), models which typically measure around 2mm wider than the size rating once installed and inflated, would have been slightly narrower than the brake track width once installed and inflated. But I found the wheels comfortable enough with the 23C tires on to go for the aero benefit.

Easton EC90 Aero 55 Aero bike wheels

While the EC90 Aero 55 was first rolled out years ago, many of its design attributes are still considered modern. Easton had one of the first, if not the first carbon tubeless clincher wheelsets available in a 50mm+ depth and one of the first to go ultra-wide with 19mm bead and 28mm brake track widths. Reynold’s Strike went tubeless in 2015, HED’s carbon-alloy Jet 6 Plus came out as wide as the Aero 55 in 2014 and Bontrager’s Aeolus 5 D3 followed in 2015.

So does the Aero 55 hold up against the competition 5 years removed from its introduction? I rode these wheels for a few hundred miles and then asked Nate, one of the fastest roadies in my cycling club who also does crits and TTs (without aero bars) to give them a go solo, in group rides, and in a weekly TT near him.

We both found them very stiff and responsive to changes in speed while underway. That stiffness also helped Nate, who weighs the same but is far younger, stronger, and faster than me to get good acceleration from a rolling stop. I had more difficulty getting them up and going than the ENVE SES 4.5 I was testing around the same time that weighed just a few grams less than the Aero 55 that weighed in at 1591g on my scale.

The Aero 55 holds its speed well, is comfortably compliant, and handles confidently for an aero wheel with 23C tires. It also rides quietly, with only a little of that slicing or swooshing through the wind sound that you can get on some deeper carbon wheels when riding them really hard. Nothing that seemed to affect or take away from the riding experience. The hubs were also quiet while freewheeling, a characteristic I prefer vs the click-click-click you hear from other hub models.

Nate was impressed with the braking force whether the rims were seeing their first braking action in a while or after repeated braking in a relatively short period of time. Braking under damp conditions required more distance but nothing out of the ordinary for carbon rims with untextured brake tracks.

In dry conditions, the brakes start squealing when you brake them hard, long, or repeatedly. The SwissStop Yellow brake pads that come with these wheels also leave a pollen-colored ring on the rim. Yes, it comes off if you wash your bike regularly but it’s really bugly (look it up) while you are riding. I’d think Easton could quiet the rims and avoid the coloring with a better choice of pads. You’d be better off with the SwissStop Black Prince.

Both Nate and I agreed that these wheels didn’t handle the crosswinds very well. We’re lightweights and got pushed around a good deal, far more than I’d experienced with other deep racing bike wheels. On a day with a fair amount of crosswinds, Nate didn’t feel stable on the Aero 55 in his normal aero position during a TT and bailed for a more open one.

With a new generation of aero bike wheels arriving from many different quarters and many enthusiasts getting on board with road disc bikes, perhaps Easton has left this model unchanged for too long. If the braking noise and crosswind performance aren’t issues for you, it’s sold for heavy discounts when you can find it.

Easton has recently introduced an Aero 55 disc brake model with the same rim profile that should eliminate the braking issue on a wheelset that otherwise has some good things going for it. You can find the rim and disc brake models at the best prices from stores I recommend through this link to JensonUSA and others in Know’s Shop.

Roval CLX 64 – A twitchy ride reminiscent of days gone by

My mother used to tell me, if you can’t say something nice about someone, don’t say anything at all.

When it comes to the Roval CLX 64, I will say a few nice things about these aero bike wheels. If I took my mom’s advice, I’d probably leave it at that given my overall take on this wheelset. However, since I’m doing a review here and I always try to call it as I see it, I will say more. Out of respect for the wheelset designers, I’ll keep it short.

This CLX 64 looks appealing if you sort through specs to figure out which racing bike wheels to initially consider. It is one of the widest (nearly 21mm internal and 30mm external), deepest (64mm), and lightest (1596g rim brake and 1580g disc brake measured weights) in this category. It has a blunt nose, DT Swiss hub internals and a low number of bladed DT Swiss Aerolite spokes with external nipples.

At first blush, all of this suggests good performance.

Unfortunately, it doesn’t deliver the performance the specs would suggest. The CLX 64 rims bend easily and this negatively affects the wheelset’s acceleration. The underperforming stiffness may also contribute to its poor handling, something you really have to adjust for taking corners at speed by making sure you balance your weight as best you can on the front and back wheels.

Roval CLX 64 Aero bike wheels

Despite the CLX 64’s excellent overall braking power, you have to keep the calipers open far wider than normal to prevent the wheels from hitting the pads on typical accelerations, let alone getting out of the saddle or sprinting. Having the pads relatively far from the rims also gives you the antithesis of modulation; it seems like all or nothing when it comes to slowing down.

These deep Rovals also get blown around pretty easily, even on days with just light winds. In fact, shifting your weight a bit to reach for your water bottle or something in one of your pockets can induce instability that borders on a wobble.

But wide, tubeless rims leads to a comfortable ride, right? Who knows. Setting these wheels up tubeless is a big-league hassle. The tire beads don’t seat particularly well in the rim hooks even with a compressor and the tires lose air far too quickly once the sealant is injected and tire is fully inflated.

The term “twitchy” should have left the cycling lexicon when we went to wider tires on wider, carbon rims with rounded, wind-cheating profiles. Despite its design, this Roval CLX 64 wheelset’s challenges with stiffness, handling, crosswind management, braking, and tire sealing provide an experience that seems like a throwback to an earlier era of bike racing wheels.

If that’s what you’re looking for in a wheelset, several recommended stores in Know’s Shop carry it.


Full Priced Carbon

Campagnolo Bora WTO 60 – I’ve not been able to get a hold of one yet to test. If I do, I’ll add it to this review. (link to Know’s Shop).

DT Swiss ARC 1100 Dicut 62 and Swiss Side Hadron 625 – These are the same wheels with different cosmetics, branding, and marketing stories. The rims are designed by Swiss Side, made by DT Swiss, and use DT’s 240 hubs and Aerolite spokes. The wheels are relatively narrow (17mm internal, 27mm external for the rim brake wheelset, 20mm internal, 27mm external for the disc brake wheelset) and are heavily discounted from their original asking price though still just under $2000 (link to Know’s Shop for the DT Swiss ARC 1100 wheelset).

ENVE SES 4.5  (not the 4.5 AR) – I evaluated and chose this wheelset as the best performer in my first review of aero bike wheels several years ago. It was my first love in this category and instilled the faith in me that a wheelset this deep could be versatile enough for riding a variety of terrain and used in a range of road racing events. ENVE came out with SES 5.6 as the successor of the 4.5 and, as I’ve written above, I recommend it as the new Best Performer in this category.

According to the customer service rep I spoke with at ENVE, the 4.5 will stay in the company’s line-up, principally for those riders with bikes that don’t have the chainstay clearance for the 5.6’s wider rims. If that’s you, here are the links to top-ranked stores Competitive Cyclist and to Know’s Shop to compare prices and order the SES 4.5.

Note, it’s not a tubeless-ready wheelset.

Fulcrum Speed 55 C – For this 55mm deep clincher wheelset and its Speed 40 C sibling, Fulcrum took the earlier tubular versions of the same design and converted them to clinchers. Yes, they added a brake track treatment that makes them perform better and more predictably and they have the awesome Campy CULT hubs. However, the V nose, 17mm internal/24mm external rim that isn’t tubeless-ready makes it a derivative design.

Stiff but not comfortable (and not tubeless ready), fast but pushed around by the crosswinds (even the 40 C), it’s ready for an upgrade. You can get it for about $1750 (link to Know’s Shop) but there are others of similar design vintage like the Vision Metron 55 reviewed above that you can get for less and performs better.

HED Vanquish RC6 – Chalk this up in the column of haven’t but hope to ride it soon. HED famously refused to go down the development path of carbon clincher rim brake wheelsets, concerned that the heat generated in braking rendered such wheels unsafe. The Vanquish 6 is a disc-brake-only all-carbon wheelset. I’ve tested the Vanquish 4 (read the review here) and hope to ride the Vanquish 6 at some point. If you can’t wait, you are in good company and can follow this link to Know’s Shop to buy it online at stores I recommend.

Shimano Dura Ace C60 – The rim brake C60 is a relabeled carbon-alloy C50 wheelset with 17C width rims. The disc brake C60 doesn’t seem to be terribly modern in design and isn’t widely available. Yes, I’d like to review disc brake model at some point but it isn’t high on my priority list.

Zipp 454 NSW – Nate, Moose and I evaluated this wheelset for our last comparative review of aero bike wheels. You can find our take on it here. I’ve left it out of this review as it didn’t compare well on a performance (or price) basis. Except for its novel varying rim height, the 454 NSW rim is based on the original 2017 404 NSW, one that has been significantly updated in shape and width and now runs tubeless on the second generation 2018 404 NSW reviewed above. The 454 NSW has yet to be updated and still has an internal width of 17mm and requires tubed or tubular tires.

Value Carbon

Many brands sell 55mm and deeper wheelsets in the $1000-$1500 range. I’ve been digging into the broader group of wheelsets I call “value carbon” in a multi-part examination and set of reviews starting with my post The Best Carbon Wheelset for the Money – Part 1.

While that post focuses on 40mm – 50mm all-around value carbon wheelsets, many of the same companies also sell deeper wheels at similar prices. I believe much of what I’ve found in my research for that review extends to those selling aero bike wheels.

It’s a broad generalization but from what I’m finding so far, the saying that you get what you pay for appears to hold true among value carbon wheels. The question we roadies each have to ask ourselves is whether we need all that the full-priced wheels provide.

There are 10,000 words about this in the post I linked you to above so I’ll stop here and encourage you to go there if you are interested in reading more.

Carbon-Alloy Wheels

The late Steve Hed and his HED Cycling company were one of the original innovators along with Zipp in aero wheel design. They demonstrating that a wide rim, round-nose, toroid-shaped rim could give you lower drag and better crosswind management than a traditional narrow, flat-sided, V-shaped one.

Unlike Zipp however, he didn’t think that carbon clinchers could manage the heat energy produced during braking. Instead, he focussed his innovation on deep carbon tubular wheels and also developed carbon-alloy wheels using the toroid rim shape. This second group of wheels combines a shallow alloy inner structural rim to dissipate the braking heat bonded to an outer carbon fairing to get the desired drag performance. You get the aero benefit of the deeper carbon rim shape with the superior braking of an alloy wheel.

Other companies – most notably Shimano, Mavic, and Campagnolo – who are more conservative in their product design initially followed the same braking philosophy as HED and made carbon-alloy clincher aero wheels instead of all-carbon ones. While these wheels were sold for far less than all-carbon clinchers, they were also far heavier and best for riding flat terrain doing triathlon and time trial events.

While HED and Shimano still sell carbon-alloy rim brake wheels, Mavic and Campagnolo now make all-carbon rim brake wheels. HED and Shimano have also begun making all-carbon disc brake clincher wheels. None of these companies has introduced a newly designed carbon-alloy wheelset in some time.

The introduction of the class of value carbon wheels has given options to those who want the lighter weight of all-carbon aero bike wheels at the lower price of carbon-alloy ones.

For all these reasons, I don’t think there’ll be much of a market for carbon-alloy wheels going forward and suggest you look for a better option among the all-carbon aero bike wheels available.

* * * * *

Thank you for reading. Please let me know what you think of anything I’ve written or ask any questions you might have in the comment section below.

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First published on April 23, 2019. Date of the most recent major update shown at the top of the post.


  • Hi Steve. Why is there such a difference between the acceleration of the rim and disc bontragers?

    • Danny, Good point. I’ve reviewed our test notes and I had the acceleration for the disc brake Bontrager too high. It’s clearly not in the same class as the ENVE 5.6 disc and more like the others I noted with a 0 the rating for the average of those we reviewed in the disc category. I’ve now fixed the chart to reflect this. As to why the Bontrager acceleration is now rated 0/average for the disc version and still -/worse for the rim, I’ll note that these are comparative ratings against a group of different wheelsets in the disc and rim brake categories and with one different tester along with Nate and me. Steve

  • Hi Steve,

    Another great overview.

    I’ve noticed from your past review of tubeless tires that very few 25c tires pass the 105 rule on the Aeolus XXX 6.

    Curious how that influences your assessment of the relative aero performance of the wheelset.



    • Kevin, There are a few that will pass the rule or come very near to it depending on where you inflate your tires. I use an 80psi pressure level for my comparative testing. That’s appropriate for a 175lb rider. The 25mm Tangente Speed Road Tubeless, my best performer recommendation comes in 104% at that pressure. If you are lighter, then you inflate to a lower pressure level which makes the tire be a bit narrower and put you at or above 105%. I ride at 145-150lbs and 70-72psi so that tire gets me (and Miles and Nate).

      The new Bontrager 25mm R3 tubeless tires, one I’ve yet to post a review of come in at 104.5% at 80psi on the XXX 6. So drop the pressure a touch you are at 105%.

      Of course, if you are a heavier rider, you’ve got to go with 23mm tires to get 105%+. The most serious aero riders, those doing time trials or TTs will pull out all the stops including narrower tires to get the max aero performance. If you’re into 28mm tires for their comfort, you probably aren’t out there looking for an aero wheelset and tire combination that gives you 105% but there are choices like the Roval CLX64 or the ENVE 4.5AR with a 28mm Specialized RapidAir or Schwalbe Pro One TLE that will give you that. Steve

      • Thanks Steve!

        When deciding on wheel/tire combinations would it be a fair assessment to conclude that going from just over 105 to just under 105 (e.g., 107 vs. 103) amounts to splitting hairs, given all the trade-offs involved?

        I noticed that Enve’s new SES tires include a 27c that is explicitly designed for max aero benefits if rocking one of their AR wheelsets. They claim it will grow to 30mm on a 25mm internal (50-85 psi), which puts it at 104 on the 31.2 mm front rim of AR4.5.

        Obviously, with a series like the AR the manufacturer is trading off a variety of performance factors, but would you speculate that part of the reason for accepting this narrower wheel/rim ratio is the added aero benefits that a hookless bead supposedly provides (limiting disturbance at tire/rim interface)?

        Also interesting to reflect on the fact that the AR series was designed at a time when 28c tires were far far wider. The wind tunnel tests I’ve seen (large grain salt – but impressive on the face of it) of the AR 4.5 were done with old pro ones at around 31mm measured (e.g., Tour Magazin, Hunt, and Enve’s own testing).

        As always greatly appreciate your expertise and candor.

        • Kevin, From what Mr. 105 (Josh Poertner) has written (see my tubeless article for links), things drop off precipitously below 105 and improve incrementally above it. As to the ENVE SES tires, my jury (Nate, Miles and me) is still out on those tires. We tested a preproduction set and they weren’t as advertised in several ways including sizing. We’ll test some production models in the spring. Meanwhile, if you need new tires, I’d stick with the knowns. Steve

  • Hi Steve, I keep coming back to your articles as I am hoping to purchase a new bike soon (has to be Italian!). Anyway, I am still trying to pick a pair of carbon disc wheels. I am looking for an all-rounder, and I am also hoping to go to the Dolomites in the future. I keep trying to locate an article you did about myths or change of opinion on wheel depth. While I have mostly rollers where I live, there is also a lot of crosswinds, and that is the biggest issue from keeping me from purchasing a deeper rim tire. Can you add a link where you have talked about this? Thanks!

  • If one is racing in bunches (i.e. most of club racing) then aero wheels have NO HELPFUL EFFECT. The bunch is being aero for you.
    If you’re off the front they’ll be a help but few of us get to do that. If you’re off the back of the bunch…your race is over!
    Light weight wheels will always help over heavier wheels up climbs – even short non steep climbs.
    The choice is simple – light weight wheels over aero wheels for racing.
    Aussie and NZ being flat – really?! If they’re so flat then disc wheels aren’t needed.
    NZ – a lot of it is hilly. Most of my riding (I aim for the hills) and a lot of my racing here in Auckland is hilly.
    Regards, Paul

    • Paul, Thanks for your perspective. I agree with you about the aero effect of the bunch and won’t argue with you that there are hilly sections in every country including NZ and AU, even though most of both are pretty flat. But light wheels only give you an advantage in the mountains – long, 7-8% climbs. The benefit of light wheels on short hills vs. aero wheels that might be 150 to 200g heavier but can carry more momentum into a short hill and better speed heading down is debatable.

      As long as you are riding fast enough, aero wheels are better on flats, sprints, crits, non-mountainous road races when tactics matter, TTs, triathlons, solo rides, downhills, and when you are doing your share of the pulls on small and large group/club rides.

      I love a good, light climbing wheelset when I head to the mountains but hate when their speed tops out or I have to work too hard to keep their momentum up on flatter sections.

      As to disc vs. rim, that’s a discussion for another day 🙂 Cheers, Steve

  • Hi Steve,
    I see your mention of HED alloy wheels in your article and that you say to look else where. I know everything is about Disc wheels lately but people with rim bikes should still take a look at HED Jet 6 plus wheels either regular or black series. In fact, It would be interesting for you to test out a black series out to see how close it is to Disc wheels for braking power. There is lots of data of these wheels on the web showing them very aero and comfortable riding wheelset for years. I currently have the HED Belguim plus wheelset with White Industries T11’s hubs and really love these wheels for training. Have you ever tested the the HED Jet 6 plus and would you ever consider doing so? Also if anyone out there still use the Jet 6 Plus wheels please leave comments about them.

    • Dave, Haven’t tested the HED Jet 6 but with its alloy rim brake track, I’d expect it’d be as good as wheels with disc braking and better than carbon rim brake wheels. Steve

  • Are Corima and Lighweight wheels too expensive to review? Also would like to see a review of hubs. DT 180/240 Chris King industry 9 and Alto

    • Chuck, Thanks for your comment.

      Being an independent, reader-supported site (rather than an industry-driven, ad-supported one), I want to review what I think the majority of our readers are or should be interested in choosing between and can afford. The Lightweights are indeed expensive and I don’t remember hearing from many readers asking either about them or Corima wheels. There are probably 50 different wheel brands out there, each with many models and there’s just not the time or budget to review that many of them. Price, reader demand, distribution, dealer service, technology, company track record, etc., all come into play in choosing the wheelsets to review.

      Of course, if more readers support the site by buying their gear using the links to stores we recommend, buying at Know’s Shop, and the half dozen other ways I’ve laid out, we can do more reviews of more wheels and other gear and kit.

      As to hubs, we review them as part of wheelsets. Most readers aren’t building wheelsets from rims, hubs, and spokes so we review how the hubs perform in a wheel system that you can buy rather than as independent components. Steve

      • Well thanks so much for taking the time to respond. I may be spending more time on here and making future purchases form your recommended sites. Thanks again and have a great week!

  • Hi mate, a bit late to the party but this popped up in my google recommendations. Is there any reason yourself (and every other reviewer) neglects reputable Chinese manufacturers when they review wheels? I.e. Far Sports, Yoeleo, Lun/Hyper?

    Considering the major difference in cost, the minor difference in aerodynamics if there is a repeatable and measurable one, and the fact they are even uci approved and tested, they represent a much better value for money proposition for most people.

    • Jaime, I not only didn’t neglect Chinese manufacturers, I researched and wrote two 10,000-word posts about those manufacturers, companies who brand products sourced from those manufacturers, and compared wheels from those two groups and from integrated and regional suppliers. You can read those posts entitled The Best Carbon Wheelset for the Money here and here. Take a read through those posts and come back and let me know what you think about the value proposition. Steve

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