BEST LIGHTWEIGHT WHEELS FOR CLIMBING
Summary: Lightweight wheels using carbon clincher rims can be a great choice for riders who climb and race mountain roads. Of the half dozen lightweight carbon rim brake climbing wheels we tested, I recommend the ENVE SES 3.4 as the Best Performer and available at the best prices from my top-ranked stores here, here and here, and the Bontrager Aeolus XXX 2 as the Best Value and available here.
Before I began the research for this review I didn’t get why someone who wanted the best climbing wheels would buy carbon clinchers.
If you do uphill road races with names like Deadman’s Ascent and Climb to the Heavens or regularly ride in a range like the Sierras or Pyrenees, I’d think you’d want the absolute lightest of everything, including lightweight wheels. That would mean going with tubulars, not clinchers.
Likewise, if you aren’t the kind of rider that likes to brake late going into switchbacks and accelerate hard coming out of them or you aren’t that excited about reaching 80 km/hr (50mph) down mile-long 8 to 12% grades or you are planning your first week-long cycling vacation in the Dolomites or Rockies, then wheels with alloy brake tracks rather than carbon ones are probably better for you.
Yet leading wheel makers from A to Zipp including Bontrager, Campagnolo, ENVE, Fulcrum, and Roval make carbon clincher climbing wheels.
What’s going on?
In this review, I look at the latest group of carbon clincher climbing wheels, those lightweight wheels from leading wheel makers, explain why they are the right choice for some riders, tell you which I like and don’t and why, and link you to where you can find them in stock, at the best prices and from online stores with high customer satisfaction ratings.
Related: Not sure what kind of wheels to get? Click Road Bike Wheels – How To Choose The Best For You
WHAT YOU NEED TO KNOW ABOUT THE LIGHTWEIGHT WHEELS
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WHAT CARBON CLINCHERS ARE TODAY
The first generation of carbon clincher wheelsets rightly earned a horrible reputation. They were fragile and subject to cracking or worse for no apparent reason. They squealed when you put on the brakes. They slowed, but never really stopped your bike in the rain. And the heat generated from excessive braking going downhill could cause blown tubes and warped rims.
If you’ve been riding for any length of time, you’ve probably heard stories from fellow riders who’ve had some of these experiences or had them yourself. It’s hard to erase those from your memory.
The best lightweight wheels for climbing come from companies that are now somewhere in their third or fourth generation of making carbon clinchers. While it’s hard not to forget what those first-generation wheels were like, the current generation product from established wheelset makers is very different. (Note that bargain-priced, no-name carbon clinchers made in open molds are usually first or second generation wheelsets and I wouldn’t recommend them for riding in the mountains or even on the flats.)
I’ll spare you the tech talk and marketing mumbo jumbo about what’s changed and how much better today’s carbon clinchers are. In simple terms, the latest generations of carbon rims from the best wheel makers use resins and manufacturing processes that make carbon clinchers more durable than alloy ones and their rims resistant to overheating in all but the most abusive braking situations. Better brake pads have greatly reduced and, in most cases, eliminated brake noise and are also part of dissipating the heat created at the rims.
The latest generation of brake pads and brake track finishes have brought the dry weather braking performance of carbon clinchers on par with alloy wheels and wet weather braking within range.
As riders, we have also adopted braking techniques that serve us well when riding carbon clinchers the same way any group of riders adapts to new products that can improve our performance. For example, TT riders have changed their body position using aero bars and enthusiasts are training differently to benefit from power meters.
Specifically, I and others who have learned how to get the best out of carbon clinchers don’t drag the brakes when riding downhill as many riders will when braking on alloy wheels. We also alternate braking the front and back wheels. Doing this should allow you to give each wheel 2-4x the amount of time cooling as braking.
We engage the brakes firmly and get off them quickly rather than ease into it and hold them a bit longer as with alloys. In the rain, we know to give ourselves a little more time and we brake a little harder when we first get on them to clear the water from the brake tracks.
Do you need to do this? Not totally. I’ve tested current generation carbon clinchers on 8%, 1 mile downhill stretches dragging the brakes the whole way and they aren’t even warm to the touch at the bottom. I’ve also used carbon clinchers with textured brake tracks on flat stretches in the rain and, with the best ones, you can’t tell a whole lot of difference compared to braking on alloy wheels.
Should you adopt these techniques? Absolutely. It just so happens that they maximize both your performance and the longevity of your wheels. You don’t go out and buy a carbon clincher wheelset that enables you to go faster just so you can drag your brakes going downhill. That would be like going out and buying an aero bike and seldom getting in the drops or buying a power meter and not changing your training.
Has your view changed?
When I wrote my first post on the best climbing wheels, it was three calendar and model years ago. While some of the carbon clinchers were much improved then, not all wheel makers had adopted some of the improved resins, manufacturing techniques, brake track treatments and pads I wrote about above. And none of the CCC (carbon clincher climbing) wheels I’ve reviewed in this post had been introduced.
So yes, my views have changed about using carbon clinchers in the mountains along with the improved and recently introduced wheelsets. If you’re interested, I wrote a post titled 5 Beliefs About Choosing Cycling Gear I’ve Dropped which describes this and other beliefs I’ve changed on gear weight, crosswinds, power meters, and hand-built wheels.
Are tubulars still better than carbon clinchers for climbing?
Tubulars are definitely lighter than clinchers, typically by 150-200 grams, an amount you’ll notice. So if you are racing, this can gain you a second or two a mile going up long, steep climbs.
On the other hand, if you don’t feel that amount of time savings is worth the extra work of gluing on tubeless tires and the added time you might need to spend dealing with them if you have a flat on the road, then clinchers are the way you want to go.
As I discussed above, current generation carbon clinchers no longer have the overheating issues that used to put them at a disadvantage to tubulars. In fact, you could argue that a bad (or even a good) tubular glue job on a particularly hot day in the mountains might result in the tubulars coming off their rims, as has been known to happen. I really don’t want to go there for the purposes of this post other than to say that it’s probably as real a possibility as someone cooking a current generation set of top carbon clinchers after dragging their brakes for miles down an alpine descent.
Actually, I’d probably go tubeless with my CCC wheels rather than tubular or tube & tire. If you’ve done any serious climbing, it’s just a reality that many mountain roads aren’t in great shape. They don’t hold up well with the winter weather most see and aren’t maintained as well as more heavily traveled main roads or tourist mountain routes (and who wants to ride those!). Fortunately, most of the CCC wheels I’ve reviewed are tubeless-ready.
Are alloy wheels still safer than carbon clinchers for descending?
If you are unsure or have doubts about carbon clincher brake tracks or your ability to ride downhill safely due to descending speeds, road traffic, switchbacks or riding technique, go with alloy climbing wheels. You can read my reviews of alloy upgrade wheels that you can also use in the mountains here. Your level of confidence is probably the most important factor in riding safely.
That said, by modifying your braking technique in the ways I’ve described above and a little experience, I think CCC wheels are equally safe and offer you potentially greater benefits going downhill and uphill.
Carbon is stiffer and more responsive than alloy. This will help your handling going downhill and translate your power more efficiently going uphill.
Carbon wheels also tend to be lighter, probably about 100-150 grams than alloy wheels of the same depth. This can make a big difference in your climbing performance, all else being equal. [“All else” includes your body weight, the weight of the stuff you carry on your bike, your bike weight, your training, your conditioning, your diet, your rest, etc. You can improve your climbing performance by making changes in all of those areas far more than getting lighter wheels.]
Finally, the better CCC wheels are wider than your average alloy wheelset. This will allow you to ride a 25C tire downhill with better comfort and stability and handle better and with more confidence going in and out of corners.
Alloy wheels will run you about half the price as CCC wheels. Tubulars will cost nearly as much. So there’s that to consider as well.
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WHO CARBON CLINCHER CLIMBING WHEELS ARE FOR
To state the obvious, CCC wheels are for climbers. And by climbers, I mean those spending hours going up and down 7%, 8% and even steeper pitches that go on for kilometers or miles at a time.
I don’t mean those of us who regularly ride “rollers”, those 4-5%, quarter mile or km hills that might total 5 km or miles during the course of a 40 to 75 km or mile ride that might also include a half km or even a half-mile climb that averages 7% during your ride.
Yes, you could certainly ride CCC wheels on those kinds of rides to give you some advantage going up steeper sections. But you have to ask yourself whether what you gain on the hills with CCC wheels is worth what you lose on the flatter sections and downhills not riding a more aero, 40-50mm deep all-around.
My experience? I really miss the deeper wheelset on the flats and going down the rollers when I’m riding CCC wheels or any lower profile wheelset on all but the steepest climbs and long rides.
For example, I did a 125 mile/200 km long ride last year with 8500 feet/2600 meters of climbing on a 25mm deep, 1350 gram CCC wheels that included two steep, long, tough alpine climbs that exceeded 12% on average. The CCC wheels were great on those climbs, the best I had ridden from that model year, but I think I worked just as hard if not harder trying to keep up with the group on the far more frequent flat and rolling sections because I didn’t have deeper wheels.
I also did a steeper, shorter route, a 100 mile/160 km ride with about 11,000 feet/3350 meters of climbing this year on a set of 1425 gram, 33mm deep set of CCC wheels. It seemed that I was always climbing or going downhill on that ride and I’m glad I was riding those wheels.
What about riding a deeper set of carbon clinchers in the mountains? Is it worth getting CCC wheels at all?
I’ve done a 135 mile/220km ride with 8100 feet/2500 meters of vertical each of the last three years with different, top-performing wheels ranging from 38mm deep, 1470 gram all-arounds to 48mm deep, 1575 gram aero wheels. They all climbed fine, though certainly not as easy as the lightest CCC wheels would have. Let’s just say it wasn’t the wheels that were holding me back on the climbs.
On the flatter sections of the route, and there were far more of those, the deeper, more-aero wheels were clearly the right choice.
Where I ride and even when I do all but the steepest of the kind of 100+ mile long events like those I’ve just described, all-around carbon clinchers are the way to go. More about the best of those wheels in my review here.
If on the other hand, I lived at the foot of or regularly visited the Rockies, Sierras, Pyrenees, Alps, etc., I’d definitely go with CCC wheels. As you’ll see, some of the newest CCC wheel models are about 50-100g heavier, 10-15mm deeper and shaped to provide aero benefit. If their stiffness, rolling, handling and other performance factors are first-rate, they outperform traditional lightweight, low profile climbing wheels.
Of course, you could always have a support vehicle follow you and do a quick change to your CCC wheels when you hit the big mountains and switch back when you get off them. What? Your friends or spouse not into that? Mine either.
Regardless, CCC wheels are also for those of you with deep pockets (and good spousal relations… or spouse-free riders). A CCC wheelset may often be a third or fourth one in your quiver. You may still have your stock wheels that came with your bike or another alloy set you use for all-weather training. You may also have a mid or aero depth carbon clincher (or both) for most of your training, group riding, road racing or TT riding. As most of these CCC wheels cost at least $2000/£1500/€2000 and many run half again more, it’s not a purchase for those trying to stick to a cycling budget. Lucky you!
LIGHTWEIGHT WHEELS SELECTION CRITERIA
So if you believe weight is the primary benefit of riding a dedicated climbing wheelset, is that the primary criteria to choose between them? Far from it.
When I evaluate wheels, I look at four groups of selection criteria and about 20 specific ones within those groups. You can read all about those here.
Immediately below, I’ve highlighted which of those criteria are relatively more important for wheels you’ll want on long, steep climbs and descents.
As you can see from the criteria I’ve emphasized for picking wheels for the mountains, half of them – aerodynamics, compliance, braking, and rim profile – are not criteria you would consider in choosing what has been traditionally thought of as a ‘climbing wheel’. These are important characteristics to ride fast and confidently on the high speed, steep descents you’ll experience going down a long mountain pass.
In these situations, you’ll want aerodynamic wheels for max speed with rim profiles that keep the bike stable in crosswinds. While most dedicated lightweight wheels for climbing are lower profile than all-arounds, you can still shape the rims to reduce drag and cheat the crosswinds.
You’ll also want wheels that are compliant going down often rough alpine roads and handle well as you are whipping through the switchbacks. You’ll want to be able to brake reliably at high downhill speeds and in all weather conditions and you don’t want any fading or degradation in braking on long descents.
For climbing, you might as well take advantage of lightweight wheels but you also want ones that transfer your energy into power as effectively as possible. That’s why stiffness is emphasized. When you are cranking out 250-400 watts trying to keep upright going up grades ranging from 7% to 15% for what seems like forever, you want stiff wheels and the right spoke count for your weight to convert as much of your effort as possible to the road.
As I hope you can see, you have different and equally important needs going up and going down a long, steep mountain and weight is only one of many considerations. That’s why I think climbing wheels is a misnomer and you should really think about these as both climbing and descending wheels.
Finding wheels that accomplish all of this requires some trade-offs. Very light wheels aren’t usually the stiffest, for example. And, aerodynamic wheels to some mean deep dish rims which aren’t usually the best at handling on windy mountain descents.
There are also some things that you really don’t want to compromise on. Older carbon clinchers have no place on long downhills where you need to do a lot of braking as they can overheat, warp, ruin the wheels and result in a blowout at speed. The CCC wheels reviewed here represent the latest generation of carbon wheels from established wheel makers that don’t have these issues if you don’t drag your brakes.
As I believe 90% or more of road cycling enthusiasts aren’t going to mess with tubular tires, you only want to be riding carbon clinchers with the latest generation of high-temperature resins, textured or etched brake track treatments, and brake pads designed and chosen to work with the rims for best heat and water dissipation performance. This is where the material choice criterion comes into play.
The heavier you are, the more these criteria matter because you’ll be putting more energy into the bike going up and will travel at higher speeds and create more braking energy going down. A rider weighing 190lbs or 200lbs or more will want a stiffer wheelset than a 150lb rider with the same power output per kilogram. He will also need more room to brake.
On the other hand, the lighter rider will be more prone to get pushed around on a windy descent if the wheel’s profile doesn’t handle crosswinds well and will benefit more from an aerodynamic profile that cuts through both crosswinds and the apparent wind created going down a mountain. None of these CCC wheels here are so deep as to really have a big problem but some are shaped better than others so as to have no problem.
Looking to the pro racing circuit for guidance on climbing and descending wheels is a mistake. The best climbers typically weigh 135 to 145 lbs, have 6% or less body fat, and are riding tubular rims on super-light, super-stiff bikes. They also have support vehicles to give them different wheels during the race depending on the terrain.
I’d guess many male road cycling enthusiasts are 160lbs to 190lbs, have 15-20% body fat (the amount for a “fit body type”), are on clinchers, and more often are riding comfortable endurance bikes than stiffer race bikes. Sorry to say, the pros and we amateurs live in two different worlds.
Even those of you lighter men and women with natural climber body types, <10% body fat, 4+ w/kg ratios and on very stiff racing bikes will still finish 10-20% (3-6 minutes on an hour ride) behind pro-level racers on the most challenging climbs. You can draw on lessons from the pros but buying the same wheels they ride hoping to get a far better result is not likely. If you could buy their genetics, you’d have a better shot.
So with all that as background, let me share with you my evaluation of the best carbon climbing clinchers currently available.
HOW THE BEST LIGHTWEIGHT WHEELS FOR CLIMBING COMPARE
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ENVE SES 3.4 – SUPERIOR STIFFNESS, AERO AND BRAKING PERFORMANCE IN A CLIMBING WHEELSET
When ENVE introduced the second generation SES 3.4 wheelset as “climbing wheels with an aero advantage”, it seemed like we were being fed a new product with an identity crisis. The first generation SES 3.4 was all-around wheels. And, ENVE also has the SES 2.2 climbing wheels in their lineup, ones I’ve previously evaluated and rated the Best Performer in my first review of carbon clinchers for climbing.
Well, I don’t know what will become of the SES 2.2 but the SES 3.4 are better climbing wheels. And, while you can use the 3.4 as all-around wheels, they aren’t fast enough to compete well with the leading ones in that category.
Anyway, those product line issues aren’t for me or you to worry about. What I have concluded, however, is that these second-generation SES 3.4 wheels rate Best Performer of all the carbon clincher climbing wheels I’ve evaluated.
Simply put, the ENVE SES 3.4 performs better than other wheelsets on most of the performance criteria that matter in choosing the best lightweight wheels for climbing.
Nate (our hill and mountain climbing specialist), Moose (our 200lb/90kg rouleur), and I (middle-aged, middling B-group rider and climber) all gave these ENVE wheels a go each on different, mountain climbing adventures we had planned during the test period. Our takeaways weren’t unanimous (that would be unusual), though, for each of the performance criteria, we pretty consistently rated the SES 3.4 better or on par with the other climbing wheels.
Nate and I, both in the 150lb/68kg weight range found the wheels incredibly stiff. Nate, whose watt/kg is so good that he finished 10th overall and podiumed in his age group his first time doing the Mt. Washington Hill Climb this year, rated the SES 3.4 stiffness top of the charts compared to the many climbing and all-around wheels he’s ridden.
I couldn’t flex them at all. Everything I had seemed to go straight through my drive train, bike frame and these wheels to the road surface. With other wheels on the same bike, that certainly isn’t the case. If you have a somewhat flexy frame, as was the case with one of the bikes I was riding during this test, putting these wheels on will harden you the f-up.
Moose, on the other hand, whose power can probably flex a steel I-beam, didn’t find the ENVE SES 3.4 as stiff as a Campy Zonda, the stiffness benchmark for alloy wheels or even as stiff as some all-around wheelsets. So, if you are a heavy guy looking for a dedicated climbing wheelset (an unlikely combination, I’ll admit), you may not find this, or any climbing wheelset stiff enough to your liking.
That same stiffness likely contributed to fantastic responsiveness and very good downhill handling. These wheels tracked well and cornered confidently in high-speed turns. We didn’t find them quite as precise or comfortable as a couple other wheelsets on test that were outstanding, but none of us had any hesitation riding them hard and fast on descents. You can put on tubeless tires if you’ll be riding them on rough mountain roads or just want a more comfortable ride.
You also notice the clear aero advantages of the SES 3.4’s added rim depth and profiles going downhill. Despite being the deepest of the wheels evaluated (38mm front, 42mm rear), they weren’t affected at all by crosswinds. Having ridden ENVE’s 10-15mm deeper SES 4.5 wheels with similar U front wheel and V rear wheel profiles with minimal crosswind effect, I’m not surprised at how well the SES 3.4 did in windy conditions.
Another huge plus for those of you who continue riding full-gas going downhill is how fast the SES 3.4 ride on gradual descents where you still need to be putting out tons of power to keep up with or ahead of those riding deeper wheels or who outweigh you. I always hate when I can beat heavier riders to the top only to have them pass me going downhill. With the aero performance of these wheels, you stand a far better chance of getting to the top and the bottom ahead of your buds. And we all know how important that is!
What about weight, you may ask. These are the heaviest wheels in this CCC category, right? Well, yes and no. Claimed weights are often notoriously understated and they are for most wheelsets in this review. The ENVE 3.4 SES with Chris King hubs that we tested for this review actually measured about 14 grams less than the claimed weight, bringing it to within you-can’t-tell distance of nearly all the wheelsets in this review.
If you want a lighter version of these same wheels, and of course the overall wheel weight matters less than the rim weight (which ENVE is one of the few that publishes), you can whack off a claimed 60 grams for the same $3000 price by ordering these with ENVE’s carbon shell hub. Alternatively, you can configure the SES 3.4 with the ENVE alloy shell hub and reduce the price to $2550 while increasing the weight to a claimed 1509 grams.
The Chris King hubs have that distinctive ratcheting sound when you freewheel that they could probably patent. ENVE’s hubs use the Mavic Instant Drive 360 internals, a DT Swiss 240-like dual ratchet design that’s quieter than the Kings but not as quiet as the DT Swiss 240s. The Kings also require annual maintenance whereas the DT Swiss design, assuming Mavic accomplished the same thing, never needs maintenance.
Personally, I prefer a quiet hub and a lower-priced wheelset that more and more wheel makers seem to be moving to but I know the ratchet freewheel sound is more traditional. A stiff, light rim is also more important than one that is less stiff now matter its weight.
Finally, there are the brakes. While we certainly don’t use them going uphill and hate to use them going down, you do need to slow and brake from time to time going into corners, when there are cars or other riders on the road, in the occasional unexpected situation, and when your heart and head tell you are going too damn fast.
ENVE’s textured brake tracks on these and their other carbon rim brake wheels are simply the best around. They are equal if not better than any other carbon wheels on dry roads. They are clearly and measurably better in wet conditions.
Yes, they sing a bit when you brake. It’s a muted, predictable song, however, far different than the shrill shrieking, squealing or squeaking you get from some other wheels anytime you brake or that comes on more and more as the tracks heat up after repeated braking.
So, all in all, the ENVE SES 3.4 are complete and terrific wheels climbing and descending the steepest, longest mountain roads you’ll find and my selection as the Best Performer among carbon clincher climbing wheels.
ZIPP 202 NSW – EXCELLENT HANDLING AND COMFORT WITH FIRST-RATE BRAKING
There’s a lot to like about the Zipp 202 NSW. It is light and very responsive, energetically following you when you don’t put out much effort.
Likewise, the 202 NSW handle confidently and comfortably going downhill, separating itself from other wheelsets with the ease at which it swoops in and out of switchbacks, with only a light touch on the handlebars required.
They brake confidently in the dry, as good as other wheelsets with a textured or etched brake track. The hum of the friction created by the NSW’s textured surface against the Zipp brake pads is muted, quieter than the ENVE SES 3.4. It was only down the steepest and longest of downhills, a 9 mile, 14.5 km descent with an average 5.5% grade that I got any squealing despite my hard and short on/off braking alternating the front and rear wheels, and only then in the last third of the descent.
On wet roads, the 202 NSW brake better than all other wheelsets in this review save for the ENVE which takes wet braking on carbon brake tracks to another level.
No, they aren’t any stiffer than average and don’t hold their speed on more gradual downhills as well as the ENVE SES 3.4 that I rated the Best Performer amongst climbing wheels. But for me, a B-group rider that enjoys climbing at about 3 watts/kg, these are among the best climbing wheels I’ve evaluated.
If your profile is similar to mine, you can click on this link to top-ranked store Competitive Cyclist or this link to Know’s Shop to find and order the Zipp 202 NSW rim and disc brake wheelsets at the best prices from the best stores.
For stronger or more demanding road cycling enthusiasts, however, the Zipp 202 NSW lacks the top-rated stiffness and aero performance you’ll likely want. The average stiffness of these will make the most dedicated climbers like fellow tester Nate look for better options. And, the limited aero benefit compared to climbing wheels that are trending deeper, wider and ultimately faster put the 202 NSW at a disadvantage for riders looking to get everything out of their descents.
BONTRAGER AEOLUS XXX 2 – EQUAL OR BETTER PERFORMANCE THAN ALL BUT THE BEST AT A LOWER PRICE
If you can’t afford or don’t want to pay the price for the Best Performer climbing wheelset, I recommend the Bontrager Aeolus XXX 2. You’ll get a very good, dedicated set of climbing wheels at about 80% of the price of my top-rated ENVE SES 3.4.
On dry pavement, the XXX 2 brakes as well as any rim brake wheelset around, better than many in this review and from other modern carbon rim brake wheels. On wet pavement, they provide the expected reduction in braking power you get in those conditions from most good carbon wheels but not up to the standard of the ENVE or Zipp.
These wheels also handle very well, giving you that planted, confident feeling when riding downhill through mountain road switchbacks. They also ride very comfortably in all conditions and damp out the bumps on rougher roads comparable with the Zipp 202.
Great dry braking, handling, and comfort are all key to letting loose yet riding safely on those fast, long, steep, and often uneven mountain roads you buy climbing wheels for.
Uphill riding and flat riding are places where these Bontragers are very capable but don’t separate themselves from others in this category.
When you are climbing, your wheelset’s stiffness is one of the keys to transferring your power effectively. The XXX 2 is solid, but a noticeable step below the ENVE SES 3.4. They lack the snappy response of the ENVE or the Fulcrum Racing Zero Carbon reviewed elsewhere in this post.
The average stiffness of these Bontrager climbing wheels also shows up in average acceleration. As with many other high-performance wheels, this set uses DT Swiss 240 hub internals, a very smooth and quiet hub I’ve never found limited performance or acceleration on any wheelset I’ve tested.
Looking at the claimed weight of 1305 grams, you might think these wheels should fly uphill. While I’ve always found the emphasis on weight is seldom borne out in performance or justified in cost relative to the importance of stiffness and aerodynamics, you’d think being 50 or 100 grams lighter than the rest would help the XXX 2’s climbing.
If you set these wheels up to run tubeless, which is the way Nate and I rode them, you pay a 100+ gram weight penalty for the Bontrager rim strips that are required to fill the rim volume. Tubeless rim strips or rim tape typically weighs no more than 10-20 grams per wheel, similar to the added weight for strips used for tubed tires. But not all rim strips are this light and that’s why I include them in my actual weight measurements.
Note that Bontrager doesn’t recommend you run these wheels tubeless with basic tape, not if you want to keep the tires on the rims.
As for crosswinds, the Aeolus XXX 2 are pretty much invisible. That’s welcome in the mountains and something you’d expect but can’t take for granted with this wheelset’s 28mm depth. The flip side of that is you don’t get much aero benefit when riding the flats.
So there are serious alternatives to consider here. Price or performance? Setup for the added comfort and handling with tubeless tires or for minimum climbing weight with tubed tires? And of course, dedicated climbing wheels or all-arounds that climb nearly as well?
If you prioritize price, comfort, and dedicated wheels, the Bontrager Aeolus XXX 2 is the best combination of price and performance I’ve evaluated in the climbing wheels category and therefore gets my recommendation as the Best Value.
You can get them online through this link to the wheelset page at Bontrager’s parent Trek store.
FULCRUM RACING ZERO CARBON – A PARTIALLY SUCCESSFUL TRANSFORMATION
The Fulcrum Racing Zero Carbon was designed to be a lighter, wider, carbon version of the popular alloy Fulcrum Racing Zero. It has a similar performance mission – very stiff, highly responsive, confident handling – that the alloy model built its reputation around.
The carbon Zeros are very stiff indeed. You turn the cranks and they go without hesitation, almost as if they are an extension of you. The handling is precise and fun going through turns downhill. With these wheels, you almost feel like a drill sergeant giving orders that are immediately followed with impressive results by an enlisted soldier.
At the same time, they have a softer side. The hubs roll smoothly and quietly as we’ve come to expect from Fulcrum parent Campagnolo’s USB ceramic hubs.
But, that’s as far as the successful performance transformation from alloy to carbon Racing Zero goes.
Braking in dry conditions on these pre-AC3 brake track technology carbon Zeros produces a shrieking headache of noise that made me want to avoid braking altogether. The noise eased off to a modest but ongoing squeal after a while despite trying different amounts of brake pad toe-ing. Shame, as they perform well and give you a confident feeling that you will slow you at the pace you want.
Do you need to bed these pads and brake tracks to make the noise go away, similar to what you do with a disc brake caliper and rotor? If so, I’d like to know-how. Textured brake tracks and pads from the likes of Zipp and ENVE certainly are audible when you hit the brakes but no different over time and with never more than a predictable dulled sound. In contrast, you get a higher-pitched, irregular noise coming from these Racing Zero Carbon wheels.
As for braking on wet days? You can try but with the carbon Zeros, don’t expect to stop anytime soon.
All of this is hard to comprehend as the Campagnolo Bora Ultras, which have the same braking treatment, performed much better and with little noise. Perhaps it was the carbon or resins used or something with the lay-up process for this Fulcrum wheelset. Hard to know.
While I didn’t expect much aero performance from these rounded edge, box-shaped profile rims only 30mm deep, I didn’t expect them to catch as much crosswinds as they did. And while they aren’t uncomfortable riding down a descent, they also aren’t as comfortable or ‘compliant’ as you can make other wheels by going tubeless at lower pressures for rougher mountain roads. These rims aren’t recommended by Fulcrum for tubeless tires.
The performance of these Fulcrum Racing Zero Carbon wheels makes me conclude that the transformation from alloy to carbon is incomplete. Great stiffness, handling, and rolling likely come, at least in part, from the Zero alloy’s hub, flanges, spokes, and bracing angles more so than from the carbon rim. The below-par braking and aerodynamics suggest that transformation from another or a new Fulcrum or Campy wheelset rim is needed.
As with other Fulcrum and Campy wheels, the Fulcrum Racing Zero Carbon MSRP/RRP bark is worse than its actual market price bite, especially at the prices you can see if you can click on these links to top-ranked store Merlin Cycles or this link to Know’s Shop where you can and order a set at the best prices from the best stores.
CAMPAGNOLO BORA ULTRA 35 – A MISSED OPPORTUNITY TO STANDOUT
Campagnolo introduced their well-established Bora Ultra 35 wheelset in a carbon clincher model for the first time in 2015 along with making the entire Bora line wider (17mm inside, 24mm outside). For these wheels, they also removed some of the resin on the brake track surface to expose the pads more directly to the carbon fibers for better bite and wet weather performance.
The improved braking performance is welcome in the mountains both in their ability to stop (duh!) but also to allow you to be more aggressive in and out of the turns, braking a little later than wheels that need more time to slow you as you approach the switchbacks.
The wheels are plenty stiff and responsive, though not out of the ordinary, both in and out of the saddle. They do feel a bit less compliant than others, consistent with the feel of most Campy wheels. Putting 25C tires on these 17C rims, something I wouldn’t normally recommend, added comfort and probably without a big hit to the aero performance that is already limited by Campy’s old school rim profile.
I included this wheelset in this comparative evaluation because it’s the shallowest carbon clincher that Campagnolo makes. At 35mm, it along with the Aeolus 3 D3 have the deepest rims among those reviewed save for the ENVE 3.4. Unlike the Aeolus however, the Bora’s rim doesn’t require tape (saving 25 grams or so grams per wheel) because the spokes don’t attach on the inside of the rims. (Note that Campy doesn’t recommend or support you running these tubeless though tires seal up rather easily to them).
Given this combination of depth and lightweight Campagnolo’s unwillingness to update their rim profile, or perhaps their lack of rim design expertise to do so, is disappointing.
The Bora Ultra 35 profile is what I would call a “box V”. Like the Shamal and Bora Ultra tubulars that this wheelset is a descendant of, the rim on the Bora Ultra 35 clincher has a flat spoke-side nose which linearly widens along the rim sidewalls until it stops for the parallel brake track. No blunt nose, rounded edges, curved sides, angled or tapered brake tracks you find on modern-day carbon wheelsets that have figured out how to cheat the wind to reduce drag and crosswind effects.
While most of the wheels in this review aren’t very aero in the first place simply due to their low profiles, this is just a missed opportunity to add downhill speed given Bora Ultra’s depth. If they shaped these rims better to make them more aero, you could use this carbon clincher for climbing and as an all-around.
These wheels, like several in this review, are priced by the manufacturer at the top end (USD$3300, £2500, €2800). Unlike some of the others, you can find them closer to USD$2300, £2000 depending on the color and hub option you choose at stores I recommend using this link to Know’s Shop.
While the innovations and performance justify these prices in other wheelsets, there’s nothing that really stands out in the performance of Ultra 35’s that would suggest to me they are worth their price. The Bora One 35 with its less expensive hubs but otherwise, similar wheelset would be a better deal if you are committed to getting a Campy.
For the best prices on the Bora One 35, you can click on these links to top-ranked stores Competitive Cyclist, use code ITKCC20 for a one-time 10% discount exclusively for In The Know Cycling readers or this link to Know’s Shop for other recommended stores.
ROVAL CLX 32 – POOR BRAKING AND AVERAGE STIFFNESS YIELDS DISAPPOINTING RESULTS
Roval has been an early proponent of tubeless, wider wheels. And, the CLX 32 was one of the first wheelsets to offer a deeper, more aero climbing clincher option. With a measured weight of 1338 grams (58 grams above their claimed weight), the wheelset is also one of the lightest in this review.
As I often have to remind myself and my dear readers, performance (and cost) is far more important than design in choosing any piece of cycling gear. Sometimes the design delivers the intended performance; sometimes it doesn’t.
Unfortunately, in the case of the CLX 32, the performance doesn’t match that of the best wheels in this review.
Yes, it feels light and is very responsive to changes in pace. But, climbing is a steady haul. Acceleration matters little (unless you are racing).
Instead, stiffness is one of the keys to uphill performance. You want a stiff wheelset to translate your power as effectively as possible from your legs through your drivetrain and wheels, and ultimately to the road. The CLX 32’s stiffness isn’t bad – it’s on par with most of the wheels in this review – but it lags that of the best.
You’d also think with rims that measure nearly 21mm wide between the beads and 28mm across the center of the brake track that it would be both quite comfortable and handle better than nearly all the others reviewed. Again, it is comfortable and handles well with wide, tubeless, moderately inflated tires intended for these wheels but really no better than the others, most of which are far narrower.
Installing tires on most tubeless wheels is a roll of the dice. Some you can put on without levers and blow up with a track pump. Others require great effort to put on and a compressor to inflate. With these Rovals, ditch the spoke-hole plugs that come with the wheels, tape the rims instead, put on the tire by hand and use a compressor.
To use a term I’ve learned from British fellow enthusiasts, it’s a bit of a “faff”.
Braking is the biggest disappointment for the CLX 32. This otherwise thoroughly modern carbon wheelset brakes like a last generation one on the wet and the dry. When you are descending after a great climb, you really want solid, confident braking and the CLX 32 doesn’t provide it. When you are up against wheels with textured, etched or otherwise treated brake tracks, you really have to bring your A-game to the descent.
Where does that leave us? While on par with many wheelsets on many of my performance measures but behind them on braking, I’m hard-pressed to recommend the CLX 32 against similarly and higher-priced climbing clinchers.
If you want to see for yourself, they are available at many retail stores that sell Specialized gear and available online in the UK and Europe at stores you can order through this link to Know’s Shop.
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First published on August 30, 2017. Date of the most recent major update shown at the top of the post.