If you are a serious regular cyclist, you need to focus on aerodynamics and aero bike wheels, two things that are critical to cycling fast on the flat earth we ride.

It’s been thousands of years since our ancient civilizations and cultures believed the Earth was flat.  The influential Greek philosophers Pythagoras, Parmenides and later Aristotle were among the first to proclaim that it wasn’t.  Explorers, cartographers, theologians, writers and many, many others bought into this notion in the years since and changed the way we think about our planet.

Clearly, none of these guys were cyclists.  And if they were, they wouldn’t have had access to today’s best aero bike wheels to spread their message.

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

The ‘Best Performer’ ENVE SES 4.5 clincher does nearly everything well and trades-off nothing for the aero performance of a deeper wheelset

Zipp’s 404 Firecrest clincher has become the ‘Best Value’ in the aero category among many competitors that took design lessons from this pioneer



aero bike wheels are less expensive but are neither as aero or as versatile as all carbon ones 


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, you are going to see a lot of flat road riding throughout the United States with no more than the occasional and short 5%+ grade hills for most of your rides.

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 and the South Pacific?  Flat. Flat. 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 live 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 Nairo Quintana, Alberto Contador and Chris Froome conquered the cycling world climbing mountains.

And why do we focus so much on wheelset weight when choosing between one or another?  Perhaps because weight is one of the most quantifiable differences between wheels, even though for most riders, reducing our own body weight by 2.5kg or 5lbs would save us 5x the amount of time we would save by cutting 300 grams off the typical stock wheels that come with our bikes by moving to a pure climbing wheelset.

If you are a serious regular cyclist, 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 flat earth we ride.

Weight only matters when you are accelerating and when you are going up relatively steep hills and climbs.  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.

Unlike weight, aerodynamics almost always matters (it doesn’t when you are slowly going up steep grades).  It matters, even more, the faster you go and the more time you spend riding without anyone in front you to draft off of.  Aerodynamics actually matters more than weight when you are acceleration though the difference between the effect of the two is marginal.

If you regularly average 30kph or 18mph and faster on your rides, aerodynamics matters a lot and can save you minutes based on how you position yourself on your bike and what gear (wheels, frame, tires) and kit (helmet, jersey, etc.) you use.  The chart below summarizes this; the posts on gear and kit (here) and training and technique (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 wheels 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, aero wheels are certainly for those riders and they will be on very deep rims, often more than 60mm deep and as much as 90mm deep or complete discs in the back wheel.  But aero bike wheels, though not ones that deep, are for roadies too.

In 2010 Zipp introduced the 404 Firecrest carbon clincher, a product that changed the direction of high-performance wheelsets.  The Firecrest had a rounded nose or spoke-bed and a toroid-shaped rim rather than the pointy nose, V-shaped profile deeper rims had at that time.  The Firecrest was also several millimeters wider than most other wheels and was 58mm deep.  It was faster than wheels much deeper but wasn’t buffeted by side winds the way even shallower wheels were and you could actually slow them down using your brakes.  It set a new standard for rim design.

Most of the leading wheelset companies followed with carbon clincher wheels that emulated the Firecrest shape, width, and speed.  Many introduced wheels in the 70mm+ range to compete with the Zipp 808 Firecrest for the speed-demon, TT and tri riders

Another group of similarly shaped, wide carbon clinchers soon came to market in the 30-45mm depth range for more versatile riding options.  The all-around carbon clincher category was born.  These wheels struggled with braking that was suspect and construction that wasn’t always on par with what you could get from alloy all-arounds which were 10 to 20mm shallower.  Since then, wheel makers have improved their fabrication processes and introduced new resins, brake track finishes and brake pads to make for better braking and more durable rims.

These all-around carbon clinchers were fast but not nearly as fast as the 70mm+ clinchers and tubulars that Zipp and others introduced for the fast-growing triathlon market.  These deepest of wheels were (and still are) the fastest wheels around and were combined with aero bars, aero frame, riders who wore aero helmets, etc.

In the last couple of years, more and more carbon-clincher wheelsets in the 50-60mm deep, round or ‘blunt-nose’, toroid-shaped, wide-rim design have been introduced.  These are nearly as fast as the very deep aero bike wheels and nearly as versatile as the all-around ones.  I call this emerging category of wheelsets aero all-around wheels.

As the aero all-around name suggests, these wheels are nearly as fast as the deepest aero wheels the TT and tri riders use and nearly as versatile as the shallower all-around ones.  The speed differences vs the deepest aero bike wheels and versatility vs all-arounders are at the margins.  I don’t think most enthusiasts are going to be compromising anything using the right aero all-around wheelset in a triathlon or taking them on all but the most demanding climbs.

The best carbon aero all-arounders don’t get pushed around by crosswinds, are stiff and comfortable, handle well, and are faster yet as indistinguishably light as the best carbon all-arounds that are 10mm to 20mm shallower.  They tick all the same performance criteria boxes (see here) as well or better than the shallower all-arounds.  They cost about the same as their shallower siblings from the same brand, which is not cheap for any of them.  But, for the serious road cycling enthusiasts who wants the most speed without losing versatility, this category is the new wheelset sweet spot that we should be riding.

In this review, I share with you my evaluation of 8 of the leading carbon aero all-around wheels and briefly compare 5 less versatile carbon-alloy wheels in this same depth range.  I recommend a Best Performer regardless of price and a Best Value where you get good performance at a good price relative to the others in this category.  For simplicity and to avoid confusion with all around wheels, I’ll simply call these “aero” wheels going forward (though don’t confuse them with the very deep 70mm aero wheels).

So let’s get on with the reviews of these wheelsets.

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Best Performer – ENVE SES 4.5

When I first started looking at wheelsets in the 50-60mm depth, I’ll have to admit that I really wasn’t sure they were for me.  As a lighter rider (68kg/150lbs), I was concerned any stiff breeze would blow me off the road and that extra wheel weight would take away my “advantage” going up the hills that are central to most of my rides.  I worried that the deeper carbon would make the wheels too stiff to be comfortable on long rides.  And I really couldn’t imagine that a deep front wheel would handle nearly as well as my stock/training Ksyriums or any of the 35-45mm all-arounds I’ve been riding for other reviews.

ENVE SES 4.5 aero bike wheels

The ENVE SES 4.5 aero bike wheels on my Specialized Roubaix endurance bike. Source:

On the other hand, I also knew that bigger guys put out more absolute power in their legs than I could and that I struggled to keep up with them on the flats.  I figured there would be some trade-off between going faster and losing some of the handling, comfort and climbing benefits I’d enjoyed from shallower all-arounds.

Really, I didn’t know how much I would gain and lose in all these trade-offs.  So I went in search of wheels that would go faster for whatever power I could muster, not be bothered by crosswinds for even light riders and wouldn’t weigh a noticeable amount more than the best regular all-arounds.

Was it possible?

With the ENVE SES 4.5, beyond what I could have ever imagined.

It seemed like these were designed to minimize the trade-offs I feared I would have to make.  Indeed, I’d say that instead of trading off anything, I’m really pushing into new territory in nearly everything.

First, my worries were unfounded.

Crosswinds?  Not noticeable despite riding in some pretty heavy ones.  No steering, leaning, compensation required.  I felt the wind on my body but not in my wheels.  I kept waiting for some pulsing or pushing sensation in the front wheel but never felt it.  I guess I have to look for stronger winds.

Too stiff?  While I’ve been on stiffer wheels, I couldn’t get these to budge laterally between some narrow gap brake pads either going up 10% + grades or sprinting full on.  Maybe a heavier or stronger rider can but I couldn’t.

Comfortable?  Once figuring out what tires and pressures suited the wheels’ aerodynamics and my weight best (25C front at 85 psi and 23C rear at 95 psi) they were as comfortable as anything I had ever been on.

Handling?  I navigated these big boys in and out of corners and pacelines with all the control and responsiveness I could ask for.

Weight?  These 48mm deep front, 56mm deep rear ENVE wheels climbed as well as any 40mm-45mm all-around I’d been on before.  Not surprising as they weigh in at 1575 grams on my scale, essentially the same as the shallower best performer 45mm deep Zipp 303 Firecrest (1570g), best value 41mm deep Reynolds Assault SLG (1552g), and most of the other carbon and carbon-alloy all-around wheels in the same depth range I’d previously evaluated (see here for that review).  These are weight differences that most enthusiasts can’t discern out on the road.

It turns out I had been riding these wheels on and off for about three weeks when I was scheduled to do the B2VT, an early season 217 kilometer/135 mile, 2500 meter/8200 foot vertical ride from outside of Boston to one of the ski areas in Vermont.  This is the longest ride with the most climbing I had scheduled all year.  I’d been having fun on the ENVE SES 4.5s so decided, what the hey, let’s see how they do on a ride like this.  (Note: Thinking about how wheels and other gear will do on this or that ride allows me to avoid thinking about how I’m going to do.)

The distance, despite a steady headwind and some nasty crosswinds for what seemed like the whole day, was not a problem.  These wheels were well planted on the road and plenty comfortable riding on my Roubaix.

While they didn’t climb like the 150g lighter, shallower (21mm front and 23mm rear depth) Shimano Dura-Ace C24 CL wheels I used going up three mountain gap roads on the Mount Washington Century the previous year, they settled right in to the cadence I wanted to tap out on the climbs and responded well to the changes in grade.  We did some long steep ones with 7-8% pitches that went on for 10K/6 miles (CAT 3) and they felt very sprightly going up and very confident going down, topping 70kph/45mph at my fastest.  Fortunately, these were long straight runs with few cars (this is Vermont) so I didn’t have to worry about a lot of braking.

OK.  I was convinced that I wasn’t trading off much if anything to get the benefits of these deeper wheels.

ENVE SES 4.5 Wheelset aero bike wheelsThe benefits?  Speed.  Faster than 35-45mm deep carbon, toroid shaped, wide rimmed all-around wheels.  No doubt. These and most of the other modern carbon clincher aero bike wheels go faster than shallower all-around wheels.

I have a two-mile nearly flat section of road where I do my flat road interval training.  It’s totally unscientific but running the deeper 50-60mm all-arounds versus the shallower 35-45mm ones there showed I could ride consistently faster at the same power output, with same tires, in a similar body position, etc.  And I feel like I’m going faster too.  Oh, what a feeling.

Nearly all the carbon aero wheels I’ve evaluated for this review will give you more speed.  It’s impossible to know whether the ENVE SES 4.5 is faster, the same or slower than any of the others in this deeper all-around category.  From looking at the few publicly available wind tunnel tests, the amount of difference between many of them is so small that you, my dear road cycling enthusiast, wouldn’t be able to isolate it out on the road.

The latest version of these and all the ENVE SES wheels have a new textured braking surface.  I rode the 4.5 with the first generation surface and thought they were great –  quiet, comfortable and consistent from the first day I rode them.  Knowing they are carbon rims, I didn’t ‘drag’ or hold on to the brakes for long periods going downhill and since I can choose when I ride, I didn’t spend a lot of time on them in the rain.  But I found they braked perfectly fine and gave me plenty confidence.

Yes, I did ride them knowing not to drag the brakes, alternating braking front and back on long descents, and giving myself plenty of time to slow in wet conditions.  If you try to ride any carbon wheelset like you ride one with an alloy brake track, you are looking for trouble.

And they were totally cool (pun intended) braking on downhills.  I checked the rims at the bottom of each of 5 times down my 1+ mile, 8% hill repeat training course one day in the summer and they weren’t even warm.

I rode the new textured brake track on the ENVE SES 2.2 for a review on carbon clincher climbing wheels (see here).  These textured track ENVEs brake even better.  I’m not going to try to get quantitative on you and say they are x% better or keep the rim temp y degrees cooler, I’m just going to qualitatively say they give you even more confidence.  What worked well before works even better now.

Do they brake as well as disc brake wheelsets or rim brake wheels with alloy tracks?  No, though it seems the gap is considerably narrower versus alloy wheels.  Are they one of the best carbon braking tracks I’ve been on?  Yup.

Another difference I’ve noticed between the first and current or second generation ENVE brake tracks is the sound they make when you apply the brakes.  The last gen put out a barely audible “shhhh” sound, the kind you make when you are trying to quiet a baby.  The new generation tracks sound to me like a dentist’s drill while you are under anesthesia.  Zing, zing, but not so much as to scare you.  While I much prefer the shhhh sound, the drill sound of the new generation isn’t troublesome and nothing like the shriek you hear on some carbon rim brakes.  On one group ride I took, one of the guys I was riding with and didn’t know before the ride made a point to tell me he thought the sound of my brakes was “really cool.”  So, there you go.  I’m sure I would have heard from others if they thought it was “really annoying.”  I’ll take cool any day.

Personally, I like the look of the wheels.  The quality also is first-rate.  The first gen brake tracks I rode on the SES 4.5 showed minimal signs of wear after four months.  They remained true despite my hitting a major pothole, double flatting and cutting through both tires on one of the first group rides I did with them.  Yeah, following some rookie’s wheel.  Stupid me.

If there were any faults I could find with the ENVE, I’d probably pick on two things.  They didn’t accelerate any better than the others and they may not be as stiff as some of the others.  The acceleration is probably determined by the weight of these wheels along with their aero shape.  They weren’t worse, they just weren’t any better.  They use the very competent and quiet DT Swiss 240 hubs that wheels from Bontrager, Reynolds, Roval and many others do. (You can also get them with Chris King or ENVE hubs but it will cost you more.)  The actual weights of those three wheelsets are within 25g of the ENVEs and all but the Reynolds have a similar rounded nose so maybe I shouldn’t expect any different acceleration.  Again, good but not any better than the others.

As I mentioned before, I found these both vertically stiff and laterally compliant.  At my weight, most wheels feel very stiff; these felt a touch less so.  It may be that they will also be plenty stiff for heavier riders too.  Rather than drilling the spoke holes into the rim, they mold them which theoretically makes the whole rim stiffer.  They don’t have a weight limit on these wheels or make a Clydesdale version for heavier rides.  Seems that they’ve designed them to be stiff and comfortable for heavy riders too.  A couple of 200lb/90kg big boys comment in my all-around wheelset review that they have found the shallower ENVE SES 3.4 wheelsets to be plenty stiff for them and they had broken spokes on other carbon wheelsets before moving over the ENVEs.

So what makes the SES 4.5 my choice for Best Performer?  All of the carbon aero bike wheels I’ve reviewed below are good and many are great.  Most have some drawbacks.  It’s the combination of all the good things that the ENVE SES 4.5 wheels do with none of the drawbacks the others have that separate them from the rest.

Combining two different rim designs into one integrated wheelset may be part of what makes the SES 4.5 perform so consistently well across all criteria.  Perhaps you would be better off with the same front and back wheels if your weight was distributed evenly on your bike, or the aerodynamics were the same coming at your front and back wheels, or you turned the back wheel the same way you did the front or any number of other things that make the life of a front and back wheel so different.

Modern wheels have different front and back wheel hubs, spoke counts, spoke configurations and often spokes to deal with the different forces these wheels?  If this is the case, then why should the rims be the same on the front and rear wheels if the aerodynamics are different at different places on the bike, especially for a set of “aero” wheels whose purpose is to be more aerodynamic?  Duhhhhh!?!?! …. as my daughter says to me when discussing other topics she figured out light years before I did.

I’d guess it’s an extra challenge and expense to design two different rims that together serve an integrated purpose into one wheelset, but it makes sense even to a practically minded road cycling enthusiast like me.  And rather than just putting a shallower wheel on the front than on the back as you can do with many of wheels from other brands I’ve reviewed below, it seems that there is so much more going on.  The front and back wheels not only have different depths (claimed 48mm/56mm but I measured them closer to 49mm/57.5mm), they also have different widths, different rim profiles and probably a lot of other differences built into them that I don’t understand.

Front wheel collage 2Rear Wheel Collage

I will really miss these wheels but I don’t get all weepy when I think about them.  I buy or return every set of wheels that I evaluate; these were only a test pair.  I can’t (or at least try not) to get emotionally attached to any of them.  And most of the other wheels in this review are pretty great wheels if you want a very fast and versatile set of wheels that might have a few deficiencies you can overlook if you like their price point or cosmetics better than the ENVEs.  It just feels to me like ENVE has nailed it better than anyone else in this carbon aero wheelset category.  Perhaps they are ahead by being the last ones into the 50-60mm pool or that their experience with the shallower SES 3.4 and deeper SES 6.7 (now discontinued) taught them a lot of lessons that they incorporated into this wheelset.

As with all the ENVE wheels, they aren’t cheap and you don’t find them discounted often but I certainly think they are worth what you pay for and recommend them enthusiastically.  The construction of these wheels is first-rate and ENVE stands behind them with a 5-year warranty, unmatched by other major brands.

Go to these search results at Know’s Shop to see where you can buy the ENVE SES 4.5 at the best prices from stores I recommend because they have the best prices, customer satisfaction records, and selection on enthusiast-level cycling gear and kit. You can also buy it directly from ENVE by clicking through this link to

Best Value – Zipp 404 Firecrest

A new 404 Firecrest model with the prior model 404 NSW rim and the same hub and spokes as the last model Firecrest was introduced June 1 and is just now becoming available. We are reviewing it now. Go to these search results at Know’s Shop to see where you can buy the new Zipp 404 Firecrest at the best prices.

This is a review of the previous model 

This wheelset’s round nose, full toroid rim shape, crosswind deflection and carbon clincher design at a 58mm depth made it one of the pioneers of this category of aero bike wheels for the road enthusiast.  You rode fast and looked fast.  It changed the game so much that it became the new benchmark for wheels from established companies and likely motivated several entrepreneurs to jump into the wheel business.  Zipp followed this wheelset with similarly profiled, deeper 808 and shallower 303 and 202 Firecrests to make it a complete line.

Firecrest, V and hybrid toroid cross sections


For some riders, these wheels became the product we saved for, splurged on and bragged about.  Others just dreamt about them and bought something far less expensive because they couldn’t justify spending more on their wheels than they had on their bike.

The Zipp 404 Firecrest started this revolution in aero wheels in 2010.  The wheelset’s rim dimensions are unchanged since then but it has incorporated better brake track resins, finishes and pads to improve dry, wet and downhill performance.  It remains one of the best braking wheelsets amongst today’s carbon clinchers with smooth brake tracks.  The hubs were upgraded for the 2014 model (88 front and 188 back, which were subsequently recalled) and spokes were added (2 in the front, 4 in the back) in 2015 to improve the 404’s stiffness and durability.  A new hub (so-called V3 or 77 front, 177 back) with a modified flange geometry and increased axle diameter was introduced on the 2016 model to provide additional lateral stiffness.

Zipp 404 FirecrestEven with these updates, the 404 Firecrest is now more a benchmark, a symbol of the kind of wheelset we aspire to ride but no long the wheelset we must ride.  It’s not as comfortable or wide or light as others in the group of wheels that have followed it.  It’s probably just as aero as it ever was, which is to say among the best both in reducing drag and handling the crosswinds but others wheelsets feel just as fast now and ahead of the 404 Firecrest in the areas I’ve listed above.  The MSRP/RRP of the 2016 model was reduced by 20% to $2100/€2,200.  Their performance and price make them the best value wheelset in this category.  I almost can’t believe I just recommended a Zipp product for its value more than its performance but in the case of the 404 Firecrest, it brings a lot of both.


Carbon Wheels

Zipp 404 NSW – A top pick for flat road races, crits, TTs or solo breakaways 

A new, wider (19C), lighter (1620g) tubeless model with an updated rim shape and the same hub and spokes as the last model was introduced June 1 and is just now becoming available. We are reviewing it now. Go to these search results at Know’s Shop to see where you can buy the new Zipp 404 NSW at the best prices.

This is a review of the previous model.

Despite the similarities in name, the Zipp 404 NSW and classic Zipp 404 Firecrest are quite different wheelsets.  Yes, they did add a textured brake track and are using a new hub on the NSW but they’ve also changed some of the rim’s key dimensions, something they’ve never done to the 404 Firecrest as they’ve updated it over the years (see review above).

The 404 NSW wheels are a good deal wider (about 1mm at the bead hook and 2.5mm at the brake track per my measurements) and lighter (about 150g) than the 404 Firecrest. They are still dimpled, not tubeless and should be run with a 23C tire to minimize the aerodynamic drag.

TZipp 404 NSWhese remain very fast wheels and good in crosswinds.  Zipp makes quantitative claims about the % improvement that I can’t verify.  But, on the road, I can tell you they are fast, maintain your speed very well and are minimally affected and quite easily managed in heavy crosswinds.  They were one of the fastest wheels I’ve ridden in my highly unscientific 2-mile interval training repeats and just barely noticed the wind (or view) coming off the ocean in my high wind crosswind runs.

My A level, 20mph+, damn-he’s-fast bike club friend Nate summed up their sweet spot well after riding these 404 NSWs when he said: “These would be my pick in a flat road race, crit, TT or solo breakaway but I would opt for the ENVE SES 4.5 in a hillier race.”

The hubs are quiet and silky smooth both pedaling and freewheeling with a Dura Ace cassette but annoyingly loud with the SRAM one they came with.  Likewise, the wheels ran smoothly with 23C Conti 4KSII rubber but I found them downright buzzy with Zipp’s own 23C Tangente Course tires.

The brake track width measured wider than these 23C tires, comfortably in the 105-110% range, best for minimizing drag/maximizing aero performance, i.e. speed.  While I’d put a premium on aero with these depth wheels, and aero drag reduction with 23C tires will generally outweigh rolling resistance reduction with 25Cs at the kind of speeds you’d likely ride these wheels, you could run 25C tires at lower pressure to make the ride more comfortable, something where the 404 NSW don’t excel.

The stiffness and climbing were also disappointing to both Nate and me.  Neither of us are heavy guys but we both noticed that the 404 NSW weren’t terribly stiff and you could get the rear wheel to rub the brake pads if you were rocking side to side when climbing or sprinting.  They didn’t climb very well on anything more than a roller.  A bit surprised here as the 404 NSW at 1562 grams aren’t light but are as light as any of the other aero wheels in this review.

Perhaps the stiffness and climbing weaknesses come back to the hubs.  Zipp seems to change hubs nearly as often as I change cassettes and the Cognition hubs used on all their NSW wheelsets is yet another new hub for Zipp.  They don’t engage particularly fast, certainly not as fast as the ENVE or DT Swiss 240 hubs and that affects your ability to keep up with changes in speed or moves in the group and changes in pitch going up a hill.  A wider hub flange can also make the wheels stiffer, something you see with good effect on Easton’s latest Echo hub and other new hubs coming out. The rim walls also seemed a bit thinner and easier to depress than the others, perhaps contributing both to less weight and lateral stiffness.

While a wheelset this fast is not one you should buy for its braking ability, the 404 NSW certainly do brake extremely well on dry pavement and stay very cool going down steep, long hills.  On wet roads, the braking goes from average carbon to as good if not better than any alloy after a couple seconds (I counted on multiple passes), likely after squeezing the water out of their tracks.

Zipp 454 NSW Wheelset Review – A whale of a tale

The storylines in reviews of Zipp’s 454 NSW wheelset have been hard to ignore.  Whale fins, biomimicry, sawtooth, vortex, the shape of things to come.  All these analogies, descriptions and hyperbole to describe how the wheels are supposed to uniquely defeat crosswinds with their rim depths that vary between 55 to 59mm.

I like a good story as much as the next cyclist but I really wanted to know how they perform before suggesting anyone buy them.

Zipp 454 NSW Aero Wheels

The Zipp 454 NSW perform like the Zipp 404 NSW I reviewed above.  As you can see, I headlined my 404 NSW review “A top pick for flat road races, crits, TTs or solo breakaways”.  I’d say all that is true for the 454.

Except, the front wheel of the 454 wobbles in the wind.  By design.  Of course, Zipp doesn’t call it wobbling.  (See stories on whale fins, biomimicry, etc.).  The wobble helps keep your bike on your line without you having to steer it there yourself.

If you ride or race a lot in windy conditions, I imagine you could get used to it and even use it to your advantage as Zipp intends.  I couldn’t.  Nate had no problems on the flats but freaked going downhill.  Moose was fine with it.

Different riders?  Yes.  Different situations?  Somewhat.  Worth an explanation? That’s what In The Know Cycling is here for.

I’m a light (150lb/68kg), B-group rider. 18-20mph/29-32kph ride average. 25mph/40kph while busting it on the flats. Fast enough to enjoy the benefits of a deeper aero wheelset but not so fast to be able to do anything about it (i.e. race).

I thought the 404 NSW was pretty good in the crosswinds.  Yes, it was affected by them but I found the effect manageable compared to other deep aero wheels I’d ridden, even with my slim arms and meh strength.  I had to steer the front wheel back in but I didn’t get blown off my line.

Admittedly, it’s not a fine line – a foot or so either way.  But, it’s a line I could keep riding the 404 NSW on even in 15-20mph crosswinds.

Normally, if it’s that windy, I’m not going out.  If it gets that windy once I’m out, I’m easing up a bit.  More because of the way my light body gets blown around than the way the wheels or the bike is.

Riding the Zipp 454 NSW in 15-20mph steady crosswinds, the wheel came back into line on its own.  Then it went out the other way.  Then came back.  Then went out.  Then came back.  Until the wind eased or I rode into a sheltered area.

To complicate matters, when the wind blew the wheel out, I initially tried to bring it back in, same as I would any wheelset.  That was a natural reaction.  That was also exactly the wrong reaction for this wheelset, as I was adding to the correcting the wheel was doing itself, only making things worse.  So I backed off and let the 454 do its thing.

It felt like a speed wobble.  A controlled, intentional, small speed wobble mind you but a wobble nonetheless.  I could see where a more disciplined rider or racer could get used to riding the 454 NSW if he/she frequently rode in windy conditions.  I couldn’t.  I’m not comfortable riding wobbling wheels, intentional or not.

I preferred the manual steer of the 404 NSW in the crosswinds to the self-correcting 454 NSW.

Nate, my very experienced cycling friend, A-group leader, and CAT 3 racer rode the Zipp 454 NSW a couple times before racing them.  Riding 25-30mph (40-48kph) on the flats in a steady side wind, he noted a “subtle micro-wobble” back toward the wind.  The 454 NSW offered a different way to deal with crosswinds than other modern wheels he’d tested for our comparative aero wheel review.

Was the wobble a concern? Not for Nate in those conditions.  Did it live up to the hype of being a radically different way to handle crosswinds?  Not really. The Zipp 454 NSW and 404 NSW handled the crosswinds differently, but both were fine.

When Nate raced the 454s down a 45mph+ (75kph) descent, however, the wobble became unstable. The winds were moderate and swirling that day. He held back the second and third time on the same long downhill leg of the three lap Bear Mountain Spring Classic course.  Others racing different 60mm or so deep rims didn’t seem to have any problems bombing downhill in the wind.

He fell back and lost several seconds from the lead group each time down the descent.  He chased back past the bottom turn after the first and second descents.  The final time down, the group was gone before he could.

Moose, my 200lb friend and president of his own mythical FFBC (Fat F*ckers Bicycle Club) felt the wobble like Nate and I did on the flats. He was totally unconcerned by it, locking in instead on the pleasure of speeding along the flats and rollers on the Zipp 454 NSW wheelset over long rides.

While he’s heavier, what separates Moose from lightweights like Nate and me and other 200lb riders I know is his barrel-shaped torso. “Strong” doesn’t do him justice.  I can only imagine that 20mph crosswinds to him are like a gentle breeze to me.

So, there you have it.  Different reactions in different situations from different types of cycling enthusiasts to the intended wobble of the Zipp 454 NSW.

If your reaction to what I’ve reported motivates you to buy a set, go to these search results at Know’s Shop to see where you can buy the Zipp 454 NSW at the best prices from stores I recommend because they have the best prices, customer satisfaction records, and selection on enthusiast-level cycling gear and kit.

Bontrager Aeolus 5 D3 – Added bead width and tubeless ready option extend wheelset’s versatility at nearly comparable performance levels

Bontrager has recently introduced the Aeolus XXX 6 wheelset with an updated rim that will become their new top-level carbon aero wheelset. We began reviewing it in September. It is available online through this link from Trek.

This is a review of their prior top aero wheelset. Steve

Bontrager recently updated the Aeolus line, introduced in 2012 in an attempt to match the Zipp 404 Firecrest profiles.  The major changes in the 2015 update of the Aeolus 5 D3 is the further broadening of the bead width (to 19.5mm) and redesign of the bead to run with tubeless tires.  Bontrager appears to be targeting the cycling enthusiast who wants a comfortable ride for on- and occasional off-road riding and who puts that characteristic above speed, stiffness, and other performance criteria.

Aeolus Drag Performance vs Zipp 404 and HED Stinger

Note: This chart was provided by Bontrager. No information was provided along with this chart about the testing protocol. Brand Z likely refers to Zipp 404 and Brand H to HED Stinger. Steve

The recent changes add to the versatility these wheelsets can already claim compared to others in this category.  Their own tests show drag performance within range of the benchmark Firecrest 404s, although details of the test protocols have not been provided – one can only guess this is the best case example.  Tests run by VeloNews on the last model of the Aeolus 5 showed that they consistently lagged the aero performance of 60mm deep wheels from HED, ENVE and Rolf Prima. This is not unexpected as the Aeolus wheels are 8-10mm shallower than the others.

At their 50mm depth, you trade-off some aero performance for better handling.  Actual weights of these Bontragers are essentially in the high 1500g range of most of the wheelsets in this review so ignore any claimed weight differences; they have no effect on anything other than your perceptions.

The Aeolus 5 is comfortably compliant on the road, brake similarly well to most other carbon clinchers introduced in the last couple of years, are competent but not the best in the crosswinds, and are not as stiff when climbing as many of the others in this category.  They ride on DT 240 hubs and spokes, known solid performers.

These wheels are available directly from Trek or from a Trek dealer.


Easton EC90 Aero 55 – Stiff and fast but crosswind and braking performance is lacking

Easton comes out of the chute claiming the EC90 Aero 55 is “the most aerodynamic road wheelset on the market today” and “fastest in all conditions.”  It’s quite bold and who knows if it’s true, but at least they have the balls to publish the results of wind tunnel tests comparing their Aero 55 tubular and clincher wheels against Zipp 404 Firecrest, HED Stinger 5 and ENVE 6.7 tubular models.  Zipp has since introduced their NSW series and ENVE has replaced the 6.7 models with the 7.8 but I wish more companies would publish their own results like Easton did.  Perhaps some brave soul (or a very rich one) will run independent wind tunnel tests to document just how different today’s wheels and bikes are.  The good old Roues Artisanales comparative tests published ten years ago now feel ancient.

Easton also shares 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

Easton’s aero tests of the EC90 Aero 55 Fantom rim with different tires.

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 $100 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 you next wheelset.  (I’m talking to you Mr. “I must put a 25C 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 run on these wheels.  According to the chart, the 21C size of the same model would be a lot fast 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.

With the EC90 Aero 55, Easton also made a serious effort to integrate some of the latest advances into an aero wheelset.  Introduced for the 2014 season, I believe this was the first carbon tubeless clincher available in a 50mm+ aero road wheelset (the Reynolds Strike followed in 2015) and the first to go ultra-wide with 19mm bead and 28mm brake track widths (HED’s carbon-alloy Jet 6 Plus also went this wide in 2014, Bontrager’s New Aeolus 5 D3 followed in 2015).

So does the Aero 55 hold up against the competition a couple 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 run near him.

We both found them very stiff and responsive to changes in speed while underway.  That stiffness also helped Nate, who weighs about 153lbs/70kgs and 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 I did, for example, with the ENVE SES 4.5 that weigh essentially the same as the Aero 55.

The Aero 55 hold their speed well, are comfortably compliant and handle confidently for an aero wheel with the 23C tires I mentioned above.  They also ride quietly, with only a little of that slicing or swooshing through the wind sound that you can get on some deeper carbon wheels when you ride 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 untreated brake tracks.  Neither of us rode these in the rain but on the 38mm deep Easton EC90 SL model with the same rim finish and lack of brake treatment, I found the stopping distance really lacking.  So I don’t recommend you take these out in the rain.

In dry conditions, the brakes start squealing when you brake them hard, long or repeatedly. (Get your mind out of the gutter!)  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.

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 modern carbon wheels this deep.  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.

The carbon clincher game is played quickly and with new players like Mavic and Shimano joining in the all-carbon aero division and stalwarts like Zipp and ENVE hardly standing still, it may be time for Easton to throw down a new aero rim profile and brake track treatment along with their current hub to keep in contact with the leaders.  If the braking noise and crosswind performance are not issues for you, go to these search results at Know’s Shop to see where you can buy the Aero 55 at the best prices from stores I recommend.

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 55m 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 regardless of their depth – fine when the sun shines, a bad bet when its wet.

Vision Metron 55Another irony is the Metron 55’s acceleration – good – vs. its weight – not so good.  Acceleration can overcome weight with a stiff and responsive wheelset, which this one is.  And while I’ve cautioned you, dear reader, not to put much stock in a few grams difference here or there between wheelsets, the Metron 55 actual measured weight from three sources I trust comes in at an average of 1705 grams (+/- 20 grams), consistent with my own experience with Metron wheels measuring about 100 grams more than their claimed weight.

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 carbon-alloy aero wheels and starts taking you out of the range of what I consider 50-60mm deep aero wheels.  While aero wheels are not those you want to climb tall mountains with, you’ll notice 150 grams of difference between wheelsets powering up short, 5% rollers that any all-around should cruise up without wondering what they are dragging.

The only other comment I’ll add is that three other reviews I’ve read on this same hand-built wheelset wrote that their Metrons came in 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, it suggests the need to be vigilant when inspecting these and any new wheelset.

Vision wheels are frequently discounted and this often makes them a great bargain. Go to these search results at Know’s Shop to see where you can buy the Metron 55 at the best prices from stores I recommend. If you ride more flats than rollers and want an all carbon aero wheelset that’s plenty stiff and you can manage trueing them up or have someone who can, the Metron 55 at the right price is worth considering.

Carbon-Alloy Wheels

The late Steve Hed and his HED Cycling company were one of the innovators along with Zipp in aero wheel design, demonstrating that a round-nose, toroid shaped, wide rim offered a faster and better handling solution that managed the crosswinds better than traditional narrow, flat-sided, V-shaped rims.  While he applied these innovations to deep carbon tubular wheels but firmly believed that carbon clinchers didn’t brake well enough to associate his company’s name with so his company has never made them.

Instead, HED’s deeper clinchers all have carbon wings or “fairings” bonded to a stock aluminum rim.  You get the aero benefit of the rim shape with the superior braking of an alloy wheel.  This also results in a lower cost and generally lower priced wheelset than the carbon ones reviewed above but it is generally heavier and doesn’t accelerate as well as all carbon of the same depth wheels do.

Other companies – most notably Shimano, Mavic and Campagnolo – who are more conservative in their product design have generally followed the same braking philosophy as HED and also make carbon-alloy clincher aero wheels instead of all carbon ones.  But none of the carbon-alloy wheels from the major brands reviewed here except HED have as wide or rounded a rim and therefore the aerodynamic performance the HED wheels do.

The trade-offs between the better aerodynamics and noticeably lighter weight you get with carbon aero wheels and better braking and (mostly) better prices that come with carbon-alloy ones are clear.  Make your decision with your eyes open.

Because of their relative heft, I hesitate to put carbon-alloy wheelsets into the aero all-around category.  They are certainly more aero than low profile stock or upgrade wheels but not as aero as the what you get from the rim shapes of the rounded, toroid carbon rims.  I also don’t think they are well suited to the variety of terrain and uses, including short climbs, hill riding or road racing that are part of the all-around wheels’ repertoire.

Carbon-Alloy Aero Wheelsets

Yes, you will see the pros riding Shimano C50 and Campagnolo Bora 50 carbon-alloy wheels, but these are almost always the much lighter tubular versions that sponsors pay a lot of money for teams to use and get on camera while they are riding.  And if you are riding behind others in the ‘peloton’ or group of riders that number 30 or more for hours on end, aero doesn’t matter a whole lot.

My bias is that these wheels are best for flat terrain riding (less than 3-4% grades), time trial and triathlon training and racing for riders with tight budgets.  There is certainly a lot of flat terrain around.  Indeed, most of us who ride in North America, Europe, Australia, New Zealand, South America and Asia ride overwhelmingly on flat roads.  So there is definitely a big demand for lower-priced carbon-alloy aero wheels that are a little heavier and less versatile than their carbon brethren but a step up from low profile wheels that come with most bikes.

For all the reasons carbon-alloy wheels are popular and to get ahead of the questions I know would come if I didn’t include these not-quite aero all-around wheels in this review, I’ll give you short summaries of my take on the most popular of them.

HED Jet 6 PlusThe HED Jet 6 Plus (available here) is the latest product in the evolution of HED designs.  It does most everything well and is probably one of the most compliant of the carbon-alloy aero wheelsets.  With a whopping 20.7 inside diameter, it’s clearly the widest but also one of the heaviest at a measured weight of 1750 grams.  For what you should really use this wheelset for (see above), weight is irrelevant and aero advanced toroid aero profile makes it, on paper, one of the fastest.  At 60mm, the Jet 6 Plus is also 10mm deeper than the other popular carbon-alloy wheels.  The fairing on these and the Bontrager wheels described below are non-structural and you can deflect them in with your finger.  It doesn’t affect the performance; it just feels rather odd. This wheel is often used with the deeper HED Jet 9 Plus for a TT set.

Bontrager Aura 5 TLR Bontrager makes the 50mm deep carbon-alloy Aura 5 TLR (Trek) in addition to their carbon clincher Aeolus 5 reviewed earlier in this post.  It rides stiff laterally yet is quite compliant (or comfortable) vertically.  it gets pushed around by the crosswinds, not surprising considering it basically has a V-shaped rim profile.  Handling is average but braking is good, the kind you’d expect from the alloy rims that this wheelset is made from.

Yes, it is tubeless ready but with a relatively middle of the pack rim width (17.5 at the bead, 22 at the brake track), I think it’s done more to keep it consistent with the differentiation Bontrager is trying to create with tubeless across its wheel lines than providing any great comfort or handling advantage.  The tubeless tires are more difficult to mount on this model than most.  Having internal spoke nipples means you (or your shop) will have to pull both the tire and rim strips off and put them on again while dealing with the mess of the sealant when you need to true the rims.  You also will get water and road dirt getting inside the fairing around the slots for the spokes.  Not for me!

You can install the regular tube type rim strips that also come with the wheel instead of the tubular ones and valve stems and save yourself the mounting hassle and about 40g of weight on an already heavy wheelset.

Dura Ace 9100 C60Shimano’s “new” Dura Ace 9100 C60 clincher wheelset is actually the prior generation C50 unchanged except for its graphics and name.  It measures 50mm deep, 17mm wide inside and 22.4mm wide outside.

While some may be disappointed that Shimano didn’t actually deliver on its announcement that these would be deeper and wider (the disc brake and tubular versions are), others may be quite alright with the C60 as it is.

Why?  The C50 was long a favorite of many riders in part for its performance and in part because of its discounted price, consistent high quality, wide availability and large service network.

These wheels feel quite robust, solid and sure-footed on the road.  Unlike the HED Jet 6 wheels which use a non-structural carbon fairing, the C60’s carbon is structural, perhaps giving it that robust feel. The hubs are… well Dura-Ace, simply the smoothest rolling, fastest accelerating and simplest to maintain hubs available today.

Price, hub and quality are probably the most favorable things I can say about these wheels and that says a lot for many riders.  The C60 clinchers, even as rebadged versions of the C50s originally introduced in 2013, are ahead or on par with carbon-alloy aero clincher offerings from their primary OEM (original equipment manufacturers) competitors Mavic, Campagnolo and Bontrager.

Much as some think the prestige of the Zipp, ENVE, HED designs are worth it, Shimano is in it for the profit that comes from volume and bleeding edge design doesn’t usually support the lower price points Shimano tries to hit to support that volume strategy. Go to these search results at Know’s Shop to see where you can buy the C60s at the best prices from stores I recommend for under $1200, £1000, €1250.

Campagnolo’s entry in the carbon-alloy aero field is the Bullet line of wheelsets.  They make them in 80mm and 50mm depths and 3 different hub bearing options – steel, ultra smooth ceramic (USB) and ultimate level ceramic (CULT).  (No, I didn’t make those names up.)

Campagnolo Bullet 50 Wheelset - CarbonThe wheels with the ceramic bearing options are called Ultra, for example, the Bullet Ultra 50, and those with standard steel bearings are the Bullet 50.  The rims and spokes are the same.  The graphics on the Ultra are a little louder.  The Ultra with the CULT bearings claims to weigh about 135 grams less though it’s at the hub, which has less of an effect on the road than if it were at the rim.  The Bullet 50 (compare prices at Know’s Shop here) is hundreds less than the Bullet Ultra 50 and one of the least expensive brand name deep wheels available.

Neither of these wheels is going to set the world on fire.  They are sluggish, get pushed around by crosswinds, and are not very comfortable.  Both hold their speed well on the flats when up to speed, brake well and are well-built.  The Ultra rides smoothly and quietly but their graphics yell “look at me.”  Upon closer inspection, the less experienced cyclist may say “wow” but the more informed enthusiast will see the boxy, narrow rims even with sunglasses on to shield the bright graphics and probably say “bow-wow”.

Note: Campy recently introduced a carbon clincher version of their previously tubular-only Bora Ultra and Bora 50.  I haven’t been on them yet and don’t know anyone who has.  There doesn’t appear to be anything particularly novel about what they’ve introduced and some of the design aspects in these wheels are a generation old. That, along with the price, doesn’t make me want to suggest you should wait for a review to help you make up your mind.

*      *      *      *     *

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  • Curious if you care to rethink your remarks about Campagnolo Bora wheels given the very throurgh and scientific carbon wheel comparison test put out by Tour Magazine in August 2016. Their test not only gave the Camapagnolo Bora One’s top overall ranking out of 19 carbon wheelsets (including the likes of Mavic, Zipp, and DT Swiss). They also performed multiple wind tunnel tests that found that Boras to be top ranked for aerodynamics, both head on and for crosswinds.

    • Scott, Thanks for your question. I really applaud what Tour does in their testing but interpret their results a little differently than you do. Note that Tour compared carbon wheelsets of different depths including some I would consider shallow climbing wheels and some mid depth 35-45mm or so all arounds. Only 7 of the 19 they teste are 50mm or deeper and the Bora One 50 ranked 6th of 7th in aero performance against those. And several of those aren’t made by companies considered to be in the forefront of aero design, e.g. DT Swiss, Mavic, Shimano, Lambda. Only Zipp and Reynolds would be considered aero innovators and the Bora One 50 trailed those. Steve

      • I actually think these Campy’s are begging to be reviewed by you, they’ve been given top ranking by an esteemed mag; now they must be scrutinized elsewhere, what better place? Btw, not to split hairs, but the Campy’s were faster than the Reynolds head on (by a measly .3 watts). True, they were slower than the Zipps head on, but by a less than heart-stopping 2.7 watts. On crosswinds, Campy actually outperformed the Zipps, but both wheelsets were beat by Reynolds. Given that the Bora’s were rated with better stiffness, acceleration, and are cheaper, I think many would be interested in these wheels, and even more interested in your review of them! 🙂

        • Scott, I hear you. If I happen on a pair, I will but frankly it’s not a priority with what else is new out there (and how long my test wish list is in this category and others already!). Note also that you are comparing the Bora against wheels that have been succeeded by newer ones. Tour tested the 404 FC which has been succeeded by the NSW. I’ve tested the 404 NSW and is very good in the cross winds whereas the 404 FC was clearly not. Also, Reynolds has discontinued the 58 Aero and now has a 65 Aero which I expect (hope?) is better than the 58. I’m looking for wheels that will top the best performer or best value wheels. This year alone we have new wheels like the Shimano DA C60, Roval CLX 50 and Reynolds 65 Aero which I’d like to test. I think Tour provides a useful reference point for the Bora but the aero wheelset world is/has moved past the current Bora and older Zipp and Reynolds wheels. The feedback I get is that aero riders either will spend the money for the fastest wheels or they are budget limited and will go with a carbon-alloy wheel at a price lower than even the Bora One. Steve

  • ref your comment Steve “Comfortable? Once figuring out what tires and pressures suited the wheels aerodynamics and my weight best (25C front at 85 psi and 23C rear at 95 psi) they were as comfortable as anything I had ever been on.”, this to me was counter-intuitive. Why not wider on rear wheel?

    • John, Agreed, it would be more comfortable still with a 25C tire on the rear wheel. I was comfortable with the 23C though and that is a more aero choice for the narrower rear rim. Steve

  • Thank you very much for your very informative reviews. I have recently places an order for a set of Enve SES 4.5 clinchers with the Enve carbon hubs. I got them for the same same price as the version with the DT240 hubs. Any experience with the Enve hubs? I just read somewhere that one person thought that the narrow rear hub causes flex allowing the rim to touch the pads.

  • Thank you Steve for this and many other informative reviews. I was wondering if you have tested the Boyd 60mm Carbon Clinchers and how they compare to the others in this category of aero wheels. I saw that you reviewed the alloy Boyd wheels in your post on Best Road Bike Wheel Upgrades and had pretty good things to say so I was a little surprised to not see the 60mm Carbon Clinchers reviewed here.

    • Austin, Thanks for your comment. Unfortunately, there are more wheels made than I have time or funds to review. I try to prioritize wheels that are widely distributed and supported, that appear to have something different or better about them, or that a number of readers are very interested in. I’ll keep these in mind. Thanks, Steve

  • Steve, thank you for your insightful reviews. I’d put a plug in for you to review Flo wheels in the future. They have received great reviews, especially from those of us concerned about budgets. 🙂 Thanks for all you do! Cody

  • hi Steve, with my budget right now means i can’t go for the enve 4.5 clinchers that i would like to get, but for half there price i can get reynolds assaults SLG. Which i know you recommended them as a budget buy, but i was wondering if i should go for the assault/strike mix set as the rim depths are nearly the same as the enve 4.5s and the price is almost the same as the assaults, but i am also worried about any flex with them with the 20front and 24back spoke set up as i am 90kgs just now with a normal weight 80 to 85 kgs but lower if i put the work in, would i be better getting a set of custom build like boyd 44 rims or 60 rims with 24/28 spoke set up for not a lot more money.

  • Hi, I am in a dilemma now as which wheels to purchase. I am just about to hit the button on buying a Trek Medone 9.5 with aelous 5. However was thinking bout swapping them for Vision Metron D40s??
    Any advice?

  • Steve, I am in for a new carbon wheelset, weigh 88 kg and ride mainly solo tours on the Dutch flats, which can be windy at times.

    I have a number of alternatives and would like your recommendation before making a final decision: Zipp 404s (177/77) at EUR 1495, Custom build Reynolds Assaults (or combo with Strike) with lightweight Tune 70/170 hubs for EUR 1497 or standard Reynolds Assaults (or Assault/Strike combo) at EUR 1199. Which would your recommend – taking into account the pricing – for my intended use? Thanks in advance!

    • Eduard, the Zipp 404s are going to be a bit of trouble in the cross winds. The Assault or Assault/Strike combo with the DT240 hubs would be my recommendation. The DT240 hub is an excellent choice and there is no need to pay more. Steve

      • Thanks for your prompt reply! Do I understand you correctly if you recommend the custom build Reynolds and not the off the shelf reynolds (which have a Reynolds Hub)? Reason for the Tunes is their light weight and the possibility to have a color option, which is not an option with the DT Swiss.

        • I don’t recommend you get the custom hub. The DT Swiss hub is excellent. Hub weight is generally irrelevant (and wheel weight on the flats is also for that matter). Paying 300 more Euro for color is up to you but I sure wouldn’t do it.

          • Steve, IMHO the Assault do not have the DT Swiss 240’s, they only come with the top-end Aero line. According to the Reynolds website, the assaults have a Reynolds Cycling Racing Straight-Pull Hub. Would this change your advice? Apologies for my folow-up questions. Thanks!

  • Steve, IMHO the Assault do not have the DT Swiss 240’s, they only come with the top-end Aero line. According to the Reynolds website, the assaults have a Reynolds Cycling Racing Straight-Pull Hub. Would this change your advice? Apologies for my folow-up questions. Thanks!

  • Any chance of testing Roval CLX 50 wheels? 50x30mm rim, 21C internal, 240S hub internals wirh ceramic speed bearings and real 1.415gr sound very nice. 🙂

  • Wow, quite an article. Very informative!

    Have you heard, seen &/or reviewed Hiro wheels?

    They are made in America and at a very affordable price point. Too good to be true??

    • Matthew, Never heard of them but looked them up. No background on company on site. Rims look very standard. Likely open mold sourced from China. Steve

  • Can you test Hunt 50mm wheelset at some point?

    • Thomas, Thanks for your comment. Hunt brands open mold wheels designed, made and assembled by contracted suppliers. These wheels, from my experience testing wheels from a few others following a similar model, are typically not competitive on a performance basis vs. top wheelsets they compare themselves to and are overpriced or underperform vs. value wheelsets designed in house by leading wheelset manufacturers. Hunt also has a pre-order and no-dealer support model that makes them less attractive when ordering product and dealing with potential product issues after receiving them. For these reasons, and the reality that there are at least a dozen wheelset marketers using a similar model to Hunt, I have chosen not to order their wheels for testing. Cheers, Steve

  • Thanks so much for the great info here! I just bought my first real deal wheels, zipp 404 firecrest, based on this article. What size Continental Grand Prix 4000S II would you recommend? Your chart says actual width of 23C is around 25mm but the max width of the wheels looks to be 26.5. Should I go with the 25C then?

    • Todd, Congrats on the new wheels. You want your tires to be narrower than the brake track width of the wheels so the air reattaches to the wheel when it comes off the tires to provide aero advantage. Brake track width of 404 FC is 24.7mm so if you want to go with the Conti, go with 23C tires which will measure just below that width on this rim at 100psi. You could also go with the 23C Zipp Tangente Course which will measure about 24.1 on that rim. They have similar rolling resistance but I find the Tangente to be a bit buzzy on the roads. Steve

  • I know you didn’t talk about this bike: Reynolds Aero 46
    But I just wanted to ask you about wheel size for this. I’m thinking about getting this wheel set but am unsure about 23 or 25c tires. I was thinking of pairing them with the continental Grand Prix 4000S II.

    • Sab, A 23C Conti GP4KSII will measure nearly 25mm wide once mounted and inflated on the Reynolds Aero 46. That width will be the right size to maximize aero performance on that wheelset which is 26.2mm wide. And it will also be comfortable. Putting a 25C Conti on that wheelset will make it wider than the rim, considerably reducing the aero benefit. Steve

  • hi steve, a friend of mine is selling fast forward F4R.
    i have stock wheels on my bike ( axis 2.0 ) which are decent by themselves, but pretty heavy and slow.
    i ride about 250 km a week and average 32-35 km over the distance including climbs. on flats i tend to average 40 +
    i weigh in at 79 kgs.
    do you think these are good enough wheels for me ?

    ( i tend to ride by the sea and the winds are very very strong there quite often )

    thank you

  • Hello Fellow Enthusiasts,

    For those of you who may be wondering, the exclusive ITK10 discount code for In The Know Cycling readers at PBK UK is still very much alive. You simply need to go to PBK UK from any link on this site and it will work fine. You can find links to PBK UK in the right hand column of any page on this site.

    The code will no longer be accepted if you go to the PBK site directly or through a site other than this one. This avoids other sites from publishing the ITK10 code and PBK providing discounts that were intended exclusively for ITKC readers.


  • Have you had a chance to ride the CW cycles Prime RP-50s or RR-50s? How do you think these will do for a budget aero option? They seem to have some of the thinks that make modern wheels decent. U profile. High TG 3K break track. 17mm/25mm width. They aren’t overly heavy for 50mm either at 1546g/1560g a pair.

    All this sounds like they will make decent wheels. The difference between the RR and RP wheels being hubs and spokes.

    Seems like something that would be a good purchase to replace my Ksyrium elites.

    Also is there a major difference in a crosswind between a 50mm rim and a 40mm?

    I WAS looking at American Classic Carbon 40 clinchers. But these Prime wheels have caught my eye.

    • Alastair, I haven’t evaluated those two but did review a set of RP-38 (rim) and RP-28 (disc). You can pop either of those two terms into the search bar and read the full reviews. Steve

  • Steve,
    Love your reviews thank you so much. I’m confused between the conclusions you draw in two different reviews:
    Best all round wheel set: ZIPP NSW 303s
    Best Aero wheel set: Enve 4.5s

    Both reviews appear to be evaluating all around wheel sets. But no Enve 4.5s in the “all round” review (but that’s how Envelope is positioning them now they’ve said the 3.4s and climbing wheels) and no ZIPP 303s in the Aero review.

    What am I missing?

    My motivation is that I am going to get a new set of all around road wheels this year. I think I’m deciding between those two wheels and so I’d love love love a side by side comparison. 🙂

    Thanks Steve!


    • John, Most of the wheelsets in the Aero review are less versatile than the ones in the All-around. Generally, the Aero wheels reviewed are best on flats and rollers while the All-arounds will more easily go climbing as well as do flats and all-around.

      The ENVE SES 4.5 is the exception in that it is nearly as versatile as the all-arounds. I had it in the Aero category largely by dint of its depth. The original 3.4 was more versatile and fit as a true all-around but the new 3.4 is really best for climbing. I’ve been thinking about whether to shift the 4.5s into the All-around category for the last couple months as I’ve been evaluating the new 3.4 and realizing it is no longer an all-around.

      Tell me about you and your riding and I’ll try to point out the things that would work best for you about each. Steve

      • Thanks Steve. I ride with the Winchester Rippers, do a lot of Harvard rides, Wachusset, B2VT, PMC, CRW centuries and just did my first Washington. I converted an old bike for Washington and found some 4th hand ZIPP 202 tubulars which were great for going up but really boring wheels for anything else. For the last 4 years my go to. Ike has been a Seven Evergreen with discs and Enve 3.4s. Thise wheels transformed the bike and I’ve used it as an everything bike but also for road rides.

        But it’s time for n+1 and I am going to get a new probably custom road bike several pounds lighter than the Evergreen so I can chase the faster riders I now aspire to keep up with. So for that bike (caliper breaks road bike) I was thinking Enve 4.5s. As you know a lot of my rides have some hills but also lots of rolling bumps. Your review of the 4.5s left me with the impression these would be more fun and faster than 3.4s on the same bike.

        I’d welcome your comments. Thank you very much.

        • John, Agree that the 4.5s would be more fun and faster than the old or new 3.4s. The 303 NSW would probably be somewhere in the middle and for the Harvard, etc. rides you are doing, probably a little better, especially if you are putting a premium on weight. I know all those rides you mention (I ride with Monsters out of Concord) and there’s a fair amount of climbing in those Harvard and B2VT routes. The 4.5s would be aces for the more modest climbing of PMC and spring CRW century. You probably wouldn’t mind using the 4.5s if you were climbing now and again but might fall out of love with them if you were doing 3-4,000 ft of climbing every 50 miles on your group rides each week.

          On the other hand, if you are a bigger power guy (3.5-4 w/kg) and you do a fair amount of solo riding or road racing, I’d suggest the 4.5s. I’ve been riding the 4.5 disc and 303 rim NSW this summer and the 4.5 speed advantage/power savings is tangible once you get up above 22mph or so. Hard to know why, as the 4.5 front wheel is just a few mm deeper than the 303 but it just shows the value of the rim shape. Then again, the 303 NSW does it all very well.

          It’s just my opinion. Ask around. Sounds like you’ve got a little time to figure it out. First world problem! See you out on the road. Steve

  • Aloha Steve, love your reviews. Wondering if you’ve tried Yoeleo wheel sets or have reviewed them before. Thanks.

  • Alastair Malcolm Stedman

    Please please review the Prime RP-50. I know you have ridden the RP-38s. But I think it would be a cool idea to review all around aero’s that are in the reach of mere mortals. I have the RP-50’s and I have been very impressed by them so far.

  • Any advise on 2017 Vision Metron 40 clinchers.

    • Not a fan of them. I rode and reviewed them a couple years ago and didn’t think they were well made. The were also much heavier than claimed, and didn’t accelerate as well or were as comfortable as other all-arounds. Certainly not as fast as those in this review. Steve

  • Steve Chen-en Tsai

    Hi Steve, What do you think use the SES 4.5 as the all around wheel in the tri-state area? I am still in the middle of decision between SES 4.5, 303NSW and 404NSW. It will be nice if I can hear some advise from people who really ride all 3 of them. Thanks

    • Steve, What mix of terrain do you ride in the tri-state area? Flats, hills, climbs? How fast do you ride? Do you race? If so what kind of races? Steve

  • Hi Steve, I’m considering Enve 4.5s and Zipp 404 NSWs. I’m 195 (88 kg) and somewhat of an aging power in Silicon Valley. My rides are a mix of rolling hills and big climbs (2500 ft up to the ridge). I enjoy the rolling hills/flats more and don’t really mind if I’m slightly non-optimized in the climbs since I’m going slower anyway at my weight. Where I ride, there’s sometimes pretty gusty winds and some days nothing. Thoughts welcome.

    Also I’m curious on the DT 280 hubs vs Enve Carbon. Probably not worth the extra $ on the carbon? But I’ve read both are excellent and great on maintenance.

    • Hi Andrew, From what you describe, I’d definitely go with the ENVE. They are aces in crosswinds, stiffer than the Zipps and far better on the climbs. The Zipps are an excellent flat and rolling terrain wheelset but at a noticeable disadvantage outside that sweet spot. The more stiff ENVE would be the biggest reason to go with them, to maximize your “aging power in Silicon Valley”. (interesting phrase – is that like Larry Ellison?)

      Both the DT240 and ENVE hubs are excellent. The ENVE are probably the smoothest rolling hubs I’ve ever been on but the DT240 are timeless quality. If you’ve got Ellison power (and money), the ENVEs are a nice extra but you’ll be fine with the DT 240s. Steve

      • Thanks,
        Ha I didn’t notice a missing key word “an aging *power* rider…” (watts in the flats translating not so well to the hills). Cheers.

    • Andrew, if you have a lot of wind (where you ride) what about the Zipp 454’s? Steve has a review of them on in the know. Others I trust out here argue if you ride in wind a lot you should try them. Good luck with there first world problems!

  • Any opinion on the Reynolds Strike?

    • CCG, Have never ridden them. I’ve always liked and recommended the Assault for their good performance and great value. Strike looks like a similarly good value if you can find them in the $1200-$1300 range where I can usually find the Assault. The Assault rim is buffered a good deal more by crosswinds than those from more expensive competitors; my fear about the Strike is if they have the same shape and are 20mm deeper they may have a similar/worse effect if you ride in windy conditions. Also one of the heavier carbon aero wheels, not an issue if you are riding flats and modest hills on TTs and triathlons where acceleration not a consideration and you ride steady pace but likely to be more of an issue if you a doing hillier riding or courses with varying pace and lots of acceleration. Steve

  • Thank you so much for this article. I was very close to buying the Shimano C60s when I read this article. I decided on the C40s instead, and I later saw the the site’s C35 (predecessor) recommendation as the best alternative to the full carbon all-rounders like the ENVE 4.5s. It’s February in Toronto, and I have yet to try them out due to a harsh Winter, but I nevertheless have no buyer’s remorse and I’m looking forward to getting out in a few weeks.

    • Just an update on the Shimano C40s. Very happy with these wheels. Clearly superior to Fulcrum 3.5 and Psyrium SLs especially, which are horrible from an aero standpoint. I don’t feel I’m being held back at all by these wheels, which hold speed well above 30 km/hr. They are still true after 3000+ kms and feel solid. What is the point of all this? I’m not sure I could justify spending an extra $2,000 for a set of ENVEs.

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