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.
For road disc bike riders, I recommend each of the wheelsets I’ve reviewed 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 lightweight wheels for climbing.
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 several model upgrade cycles 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 what I’ll call CCC or 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 clincher lightweight wheels 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 techniques, 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 (CCC) 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 criterion 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 pitches 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.
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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 of 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 lightweight wheels 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 no 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
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 lightweight wheels for climbing, I recommend the Bontrager Aeolus XXX 2. You’ll get a very good, dedicated set of climbing wheels at about 90% 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 lightweight wheels for climbing 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 that 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 these links to Chain Reaction Cycles and 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, a 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 this link to Know’s Shop for availability at 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.
HOW THE BEST LIGHTWEIGHT WHEELS FOR CLIMBING COMPARE
LIGHTWEIGHT DISC BRAKE WHEELS FOR CLIMBING
While they each suit different rider preferences, I recommend all of these wheelsets for road disc bikes.
ENVE SES 3.4 AR DISC – PERFORMANCE IS IN THE FRAME OF THE RIDER
After an initial scan of fellow tester Nate’s and my evaluation notes for the ENVE SES 3.4 AR Disc wheelset, I couldn’t help but draw a parallel to the saying about how beauty is subjective, being in the eye of the beholder and all that.
Even though we’re both “road cycling enthusiasts”, he and I are very different riders. He’s one of the fastest non-pro roadies, best climbers, most practical gearheads, and highly analytical people I know.
Me? Not so much. Average speed (18-20mph) and climbing ability. Home wrenching skills, etc., Very enthusiastic though!
It’s actually kind of surprising when our evaluations reach similar conclusions about the performance characteristics of the gear we independently test. I always welcome his take and those of my other fellow testers Miles, Dave, and Moose because they add breadth and depth to my own. Together, I hope we cover the range of vantage points and rider profiles of those of you who read our reviews. (And yes, I’m also looking to add women to the test team.)
When it came to the ENVE 3.4 AR disc wheelset, Nate didn’t care much for it. I liked most of what it had to offer.
Looking closer at our evaluations of this ENVE wheelset, it became clear to me that what set us apart was probably more about our different bike frames and riding profiles than our mental frames or subjective views of what makes for wheelset performance “beauty”.
I point this out rather than try to write some compromise of a review as these distinctions may also apply to what you would experience riding this wheelset.
The 3.4 AR doesn’t fit neatly into a single wheelset category. At about 40mm (39.5mm front, 43.5mm rear with my calipers), it’s close but not as deep as most all-around road disc wheels that go 45-50mm both front and back these days.
While it’s light (1432 grams with ENVE alloy hubs on my scale), the 3.4 AR is also not a dedicated climbing wheelset. ENVE sells the 3.4 disc (no AR) for that purpose. That review is below.
What separates the SES 3.4 AR is its 25mm internal (25.0 measured) and 32mm external rim widths (actually 32.1 front and 32.5 rear). That, along with the similarly wide, deeper ENVE SES 4.5 AR (review here) makes it far wider than most road wheelsets being made these days that measure 19-21mm internal and 27-29mm external.
It is also as wide and often wider than most modern “gravel” wheels that range from 21mm to 25mm internal width.
So is it an all-around, climbing, and gravel wheelset triple-threat that’s great on all roads as suggested by its AR name? Or, is it the wheelset equivalent of a Swiss Army Knife, one that gets high marks for its versatility but doesn’t perform as well as those dedicated to either the all-around, climbing or gravel mission?
Whether on paved or gravel roads, both Nate and I agreed the 3.4 AR is a laterally stiff wheelset. Yet in Nate’s already very stiff Specialized Venge aero frame, this strength didn’t add any benefit. In my Parlee Altum, as quick and light as a road racing frame with the comfort of an endurance one, I enjoyed how the added stiffness of these wheels helped me accelerate uphill and start above-threshold intervals (or sprints for all you racers).
Mounted on my Giant Revolt Advanced carbon gravel frame, the SES 3.4 AR disc’s stiffness was further apparent in the bike’s improved responsiveness compared to how it feels with most of the gravel alloy and carbon wheelsets I’ve been testing lately.
Vertical or radial stiffness, better known as compliance or comfort was a joy for me and a disappointment for Nate. With the latest model Schwalbe Pro One TLE 28C tires on the 3.4 AR’s 25C wide rims, you’d think they’d to soak up every imperfection on our New England paved roads.
Tire pressure is key to optimizing wheelset comfort on any set of rims. It’s hard for some to wrap their heads (and pumps) around how low you should inflate a wheelset as wide as the 3.4 AR. I pumped it to the 48psi ENVE’s tire chart recommends for my combination of body weight (145lbs/66kg), the Schwalbe’s inflated tire width (29.0mm @60psi), and the 3.4 AR’s 25mm internal width.
Yes, 48 psi. That’s not a misprint.
Nate, with his racer’s mindset, went about 8psi higher than his recommended level. (Details withheld to maintain the friendship.)
While the wheels soaked up large bumps and small potholes better than most, for me they were also notably more comfortable on paved roads than narrower wheels also run tubeless. For Nate, they were less comfortable than 19C and 21C carbon road disc wheelsets even though the 3.4 ARs were inflated at least 10psi less than the level he pumps those to, also with tubeless tires.
Dirt and gravel road comfort is principally due to tire and inflation choices. So while I found them very comfortable at 30 psi on the trail, I can’t attribute it to the ARs.
The 3.4 AR’s relative width and ability to absorb the bumps certainly created greater handling confidence that felt warranted cornering at speed on unevenly paved roads and when changing lines, with the right tires mounted, on gravel ones.
While even 21C road disc wheels are at their aerodynamic best on 25C tires, the ENVE 3.4 AR and 4.5 AR wheelsets are one of few truly designed (rather than marketed) for 28C tires. With the Schwalbe Pro One TLE pair inflated at 60psi (my measurement benchmark for 25C road wheelsets), the tires measured 29.0mm wide, well beyond the “rule of 105” rim-to-tire width ratio for optimum aero performance.
Note that the new Schwalbe Pro One measures a size down from the prior generation (i.e., current generation 28Cs measure what last generation 25Cs did) and are as much as 1.0 to 1.5mm narrower than many older model 28C tires I’ve measured from other brands. So depending on the tires you use, you may find them running very near or under than 105% ratio and closer to the same outside width of the wheels, though not likely beyond the 3.4 AR’s 32mm external rim width.
Either way, make sure you have about 38-40mm of room between your fork and chainstays for the 32mm wide rims and a 3-4mm buffer either side of them for lateral deflection when cornering.
Also, be sure to use tires that are compatible with the hookless rim design that these wheels use (see list here). More tires are compatible now than when the also hookless 4.5 AR was introduced and I believe most will before long as more road disc wheels go the hookless route.
All of that said, the 3.4 AR didn’t maintain momentum or otherwise feel particularly “aero” compared to better 50mm deep all-arounds and certainly not on par with still deeper aero wheelsets. On the plus side, it did feel a bit more sustained going forward than other wheelsets in the 35-40mm range. Also, the weeks of 10-20mph crosswinds we experienced during our spring testing rides didn’t affect this wheelset one bit.
The hubs ran smoothly with an average freewheeling sound from the ENVE alloy hubs that use Mavic Instant Drive 360 ratchet internals. You can also spend more to get these wheels with Chris King steel or ceramic bearing hubs with its signature sound and greater points of engagement that methinks is unnecessary.
Aerodynamics also plays a role in climbing, once thought to be only a battle of grams. For Nate, a very accomplished climber using a very aero frame, he felt no difference on steep, 2-4 minute climbs between the light ENVE 3.4 AR disc wheelset and his roughly 25mm deeper, 200g heavier Roval CLX 64 aero wheels. On punchy climbs less than 30 seconds, the aero wheels seemed quicker for him, perhaps due to the aero benefit he carried into those climbs.
For me, an average climber who goes uphill far slower than Nate, I had the sensation of ascending freely on the 3.4 AR wheels, limited only by my strength and fitness. From experience, I know that most 1600+ gram aero wheels hold me back, their weight perhaps overwhelming any potential aero benefit.
Going downhill, the width of the SES 3.4 AR rim and tire combination made for a worry-free, joy ride, the kind you feel on a rollercoaster knowing (or at least believing) the cart you are in is securely riding on rails.
Climbing dirt and gravel where speeds are far less than on paved roads, the 3.4 AR wheelset’s combination of light weight and stiffness provided the feeling of turbo-boost responsiveness.
Clearly, the ENVE 3.4 AR disc is a very versatile wheelset. If you ride both paved and gravel surfaces and do a lot of climbing, this one wheelset which lists for $2550 can serve you well and save you from buying one for paved and another for dirt and gravel roads.
But, if you spend most of your time riding on paved roads and at aero speeds and your mental and perhaps, physical frames are more biased to aero performance than climbing, the SES 4.5 AR disc (review here) would be a better choice.
You can get the 3.4 AR at the best prices from stores I recommend for their low price and high customer satisfaction ratings by clicking these links directly to this wheelset’s page at Competitive Cyclist, Merlin, ENVE’s online store, and others in my Know’s Shop.
BONTRAGER RSL 37 DISC – LIGHT AND NIMBLE CLIMBER
The Bontrager Aeolus RSL 37 disc wheelset is a lot of fun to ride. Scooting around with it on my bike brings me back to how I remember riding as a kid. You go left, right, up, down, and straight ahead without giving it much thought. You just go where you want without holding back.
These wheels are very light and yet stiff enough without being overly so. That’s probably the combination that made me feel so agile and free riding the RSL 37 in almost every situation. I climbed my most challenging steep, long “hill repeats” with comparative ease and did a few 50-mile, rolling rides on days after my hardest interval training of the week and felt totally relaxed and unfatigued during and at the end of those rides.
I’ll admit, I felt as though something was out of whack when I rode the RSL the first time. It was early spring with a lot of crosswinds and I was coming off too many stay-at-home-mandated Zwift rides. Early season legs, wind in my face or from the side, and bib tights can make me feel a bit slow.
With the Bontrager RSL 37 disc, I cut through all of that. I immediately felt light, almost too light and I worried I’d get pushed around in the winds. Didn’t happen. The freehub engaged on command and the wheels accelerated as quickly as I wanted and far faster than expected to the point where I had to shift down the cassette sooner than I normally do to keep up my speed.
At 37mm, the RSL rims are deeper than climbing wheels have traditionally been but about the same as the benchmark for that category set by the ENVE SES 3.4 (38mm front, 42mm rear) a few years ago. They’re nearly as deep as where carbon all-arounders have historically started (40mm) but no longer where they currently range (45-50mm).
For me, the Bontrager Aeolus RSL 37 disc is a climbing wheel. It climbs as well as any I’ve reviewed from any brand. Bontrager must think so too are they are retiring the 28mm deep Aeolus XXX 2 disc wheelset in its lineup.
At the same time, Bontrager will continue to make the 47mm deep all-around Aeolus XXX 4. Makes sense as I found the RSL 37 doesn’t sustain your momentum the way I’ve experienced with a deeper and slightly wider 45mm-50mm all-around wheelset.
The tires I rode these wheels with – 25C Bontrager R3 Hard-Case Lite and Continental Grand Prix 5000 tube-type tires and the tubeless Continental Grand Prix 5000 TL – measured within a half mm of the RSL’s 27.5mm outside width. That’s a smaller difference than the Rule of 105 calls for (rim at least 5% wider than the tire so the air to re-attaches as it moves between tire and rim) though Bontrager (and others) don’t strictly adhere to that rule of thumb in their rim design for aero optimization.
As far as wheelset weight goes, I normally don’t make much mention of it because most of us can’t tell the difference between wheels weighing within 100-150 grams of each other that is typical of what you find from wheels in the same category. But since I’m reviewing a climbing wheelset and there may be a few of you weight weenies reading along, and principally because Bontrager gives you a few options that do make a difference, I’ll go through it here.
If you want to use tube-type tires, Bontrager provides you a cloth-like rim strap along with the wheels that you can easily install by stretching it over the rim wall and snapping into the rim bed. Per my scale, these weigh 22 grams per wheel.
If you prefer tubeless tires, the cloth strips won’t hold the air or sealant. Instead, Bontrager provides you plastic rim strip inserts to go into the rim bed. Those need a bit of experience to install without cracking or breaking or getting them just enough off-center to mess up the bead lock alignment. These add 62 grams to each rim, an unwarranted penalty if you care about climbing wheel weight.
The best solution is one they don’t provide with the wheels but have approved and I found works well. Good old 25mm rim tape. One wrap or two. I tried both and each sealed up successfully. The tape weighs 5-10 grams per wheel depending on the kind you use and the number of wraps.
It seems odd that Bontrager wouldn’t include the lightest weight solution with their lightest weight wheels but, no matter how you set it up, these wheels are still going to be light. I set them up initially for tubed-tire riding with the cloth-like rim straps (1376g) and later pulled them out and taped the rims (1352g not including the valves) and mounted tubeless tires. With the 62g per wheel tubeless inserts, they’d weigh-in around 1450 grams.
At 1352g for tubed or tubeless tires, it’s an easy choice.
Enough about climbing weight already! Going downhill and cornering at speed on the RSL 37 is a confident blast. And you don’t have to worry about crosswinds riding exposed roads. Simple. Fun and done.
As to comfort, these Bontragers aren’t any more or less so than most set up with tubes and the added pressure they require even with the RSL’s 21mm inside width. As with any other wheelset this wide, you could safely lower your 25C tire pressure 5psi below the suggested level, use tubeless tires and drop it 10psi or mount up 28C tires. Wider tires would add a good deal more weight and further diminish your aero performance when riding above 18-20mph/29-32kph.
These wheels get an attractive glossy finish with black stealth logos. Also contributing to a skinny look and the low weight are the new DT Swiss 240 EXP hubs used on this wheelset. They roll a bit smoother than the last generation DT 240s but their freehubs are a bit louder even after I regreased them. They’re not nearly as loud as Chris King, Industry Nine or other hubs seeking attention and DT Swiss hubs with a very similar design to the EXP have historically required next to no maintenance.
All in, the Bontrager RSL 37 does a joyful job of its main purpose in life – climbing – and is a wheelset you can feel quite spry riding any day on rolling routes. Priced at $2400, you can order them direct from Bontrager using this link to the Aeolus RSL 37 disc wheelset page on their parent Trek’s website.
ENVE SES 3.4 DISC – AN ALL-AROUND CARBON DISC WHEELSET THAT DOUBLES AS A CLIMBER
If you want a top-performing Gen 3 all-around carbon road disc wheelset that climbs extremely well, the ENVE 3.4 Disc is the one you want.
ENVE claims the 38mm deep front rim weighs 390 grams and the 42mm rear one just 10 grams heavier. I measured the complete wheelset with DT240 hubs at 1410 grams with tape. ENVE now uses a hub with a similar design that uses Mavic Instant Drive 360 internals that claims to weigh much the same. You can also get an Industry Nine hub that weighs 20g less or a Chris King that weighs 30g more
These kinds of weights for carbon rims and road disc wheelsets scream climber. Yet, their rim widths (measured approximately 21mm wide internally and 28mm wide externally, a little more for the U-shaped front and less for the V-shaped rear) and depth (38mm front, 42mm rear) put them just over the line as all-around wheels.
As all-around/climbers go, I found the ENVE 3.4 Disc wheels to be excellent performers. While only 100 grams lighter than the ENVE 4.5 AR Disc, all of it is in the rims and made climbing notably easier when I rode them back to back.
The 3.4s seemed almost immune to crosswinds and they accelerated with the best of the other wheels I’ve reviewed here. They handled confidently making high-speed turns. This combined with their no-worries attitude around crosswinds made me very calm going fast downhill.
They are also stiff and comfortable, though on par with most of the other wheelsets for those criteria. If I was doing a lot of dirt and gravel riding, I would probably go with the ENVE SES 4.5 AR (see review here) or 3.4 AR (see review above) for a similar volume of air at a lower tire pressure the AR’s wider rims allow.
Using the same hubs and trying to keep in the same riding position, I don’t find the 3.4 hold their speed as well as the similarly profiled 4.5 AR rims. That’s to be expected due to the depth difference and isn’t an issue in group riding. If you are racing or doing long pulls, you might want to go deeper so you don’t need to work as hard.
The one disappointment with these wheels was strictly cosmetic. I noted some white markings along the spoke edge of both rims that seemed to get worse over time. The carbon in the rim’s sidewalls and spoke beds appeared well laminated and structurally sound.
As these were wheels I bought rather than demoed, I tried to look at this with a “glass-half-full” attitude.
How? I used this situation to see how ENVE’s customer service would deal with my inquiry as just another paying road cycling enthusiast rather than trying to impress the marketing or PR folks with my reviewer status for some kind of special treatment.
An ENVE “consumer experience” agent got back to me the morning after I submitted my comments along with a couple of photos I attached on their web product support form. He explained that what I was seeing was powdered curing agent that normally dissolves into the resin but had pooled up in the molding process on my rims. The agent said this happens to various degrees in all their wheels as they don’t use paint, filler or cosmetic weave layers but their tests showed no effects on performance. I can’t confirm that independently but I didn’t notice any performance changes as the markings grew more evident.
After responding that I didn’t much care for the look of these markings and would like another set, the agent pulled my product registration information and sent me a shipping label. While he said the markings on my wheels were particularly obvious and expected the replacement set wouldn’t exhibit them, he couldn’t guarantee they wouldn’t but would again replace them if the situation re-occurred.
I was fully satisfied with the service response. While I would have preferred there were no markings in the first place or that they replaced them overnight, I think this was about as good as it gets if you ever have a problem.
If you see the value in this combination of all-around and climbing performance together with good customer service and are willing to pay the added price, you can pick up these wheels at recommended stores Competitive Cyclist, Merlin, and Tredz or directly from ENVE by clicking through this link to ENVE.com.
ZIPP 303 FIRECREST DISC – VERSATILE VALUE FOR GRAVEL AND ROAD CLIMBING
I’ll admit to being a bit skeptical of the new Zipp 303 Firecrest Carbon Tubeless Disc Brake wheelset before I rode it.
I’d learned to love the unique combination of comfort and speed of the 303 NSW disc road wheels that Zipp sadly dropped from their line-up after introducing this new Firecrest. And the also new, low-priced 303 S (reviewed here) I tested before the Firecrest didn’t ride like any Zipp wheelset I’ve ever known.
So while I wasn’t sure what to expect, I feared that Zipp and their new more jagged-looking logo might still be finding their way with this successor to the Firecrest franchise.
After riding this 303 Firecrest disc wheelset on enough paved flats, rollers, and alpine climbs, and a full range of gravel surfaces to get a bead on its character, I can tell you it is blazing a new Firecrest path.
And, for what it costs and what it does, I like that path.
At USD$1900 for a Firecrest, that path starts at a low price. With the $3200 Zipp 303 NSW disc now out of production (the other Zipp NSW rim and disc wheelsets remain), that price is not only the lowest it’s been for a Firecrest in, I think, ever, but it’s also now the price of their top-of-the-all-around-line disc wheelset.
Add to that, the 303 Firecrest disc is far wider (24.9mm inside, 30.0mm outside per my measurements), far lighter (1383 grams including pre-taped rims), and somewhat shallower (40.4mm) than previous Firecrests. Oh, and it only takes tubeless tires and has hookless rims.
So all that’s part of the new path, one that Zipp claims “is designed for the real world… a world of imperfect conditions, road surfaces, and elements”. In simpler words, it’s intended to be ridden on both paved and gravel roads.
For the most part, the Zipp 303 Firecrest disc pulls it off.
As a gravel bike wheelset, the 303 Firecrest is the full package. It’s comfortable and confident, or at least makes me feel that way on any class of surface. Negotiating around rocks, ruts, branches, in and out of lines, this wheelset is nimble and responsive.
Stiffness is a plus on these 303 Firecrests. Notably, stiffness wasn’t always a characteristic strength on previous Firecrests and isn’t on other Zipp wheels if you are a heavy rider or putting a lot of watts into them. This greater stiffness also shows up on gravel climbs, where the new 303 Firecrest disc excels.
The hubs also perform well on unpaved roads. They engage relatively quickly and provide the acceleration you frequently depend on riding gravel roads with their regularly changing pitches and surfaces.
Zipp uses their own ZR1 hubset on this Firecrest, a 6-pawl, 6 degrees of engagement affair. This is also a new model for them, something they seem to regularly do with hubs every few years. Because of that, it’s frustratingly hard to know how they’ll hold up over time.
On paved alpine climbs, I found the 303 Firecrest Zipp to be nearly the equal of the best lightweight disc wheels like the ENVE 3.4 disc and 3.4 AR disc and the Bontrager 37 RSL (reviewed here). It wasn’t as snappy as the ENVEs or as quick as the Bontrager, but it was steady, strong, and felt like nearly every watt of power I put into the wheels went right to the road.
At a measured 1383 grams with the Shimano/SRAM 10/11-speed compatible freehub on the wheelset I tested, its light weight (about 30 grams heavier than the Bontrager and 40-50 grams lighter than the ENVEs) clearly makes it one you’d want to join you going up long, steep climbs.
On flatter paved roads and rollers, some of the differences between the Zipp 303 Firecrest disc and more expensive ENVE 3.4 AR disc and far more expensive Zipp 303 NSW road disc wheelset came out. The ENVE and NSW are more comfortable and roll smoother on paved roads. And the NSW is clearly faster and holds its momentum far better than the Firecrest (and ENVE).
On paved roads, I used Zipp’s Tangente Speed Road Tubeless tires, ones I’ve found to be among the best tubeless tires, I did A-B and A-B-C comparative testing of these three wheelsets. The Firecrest and ENVE with their 25mm internal width rims got 28mm Tangentes inflated to the same pressure while the 21mm internal rim width NSW was shod with 25mm Tangentes inflated to the appropriate pressure for their widths and my weight.
Each of these wheelsets uses different hubs and layups. That might explain the comfort differences.
The NSW and ENVE rim and Tangente Speed Tubeless combinations easily passed the 105% outside rim width to tire width ratio target for optimal aero performance while the narrower outside width of the Firecrest put it slightly under 100%.
While I don’t expect top-end aero performance from a 40mm deep wheelset, the 30mm outside width of the Firecrest vs. the 32mm measurement of the ENVE 3.4 AR front wheel might explain the speed difference I felt in its ability to hold speed. Unfortunately, none of the other 28mm tubeless tires suitable for hookless rims that I mounted and measured on the Firecrest – Bontrager R3 Hard-Case Light TLR, Schwalbe Pro One TL, Specialized S-Works Turbo RapidAir – got me past 102%.
But at $1900 and used primarily for gravel and alpine climbing, the Zipp Firecrest 303 disc wheelset is a great option for those riding purposes and a good value. And, for what that’s worth, I’m kind of partial to the new logo too.
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Thanks and enjoy your rides safely! Cheers, Steve
First published on August 30, 2017. Date of the most recent major update shown at the top of the post.